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Phenyl aldehyde and propanoids exert multiple sites of action towards cell membrane and cell wall targeting ergosterol in Candida albicans. In the present study, two phyto-compounds phenyl aldehyde cinnamaldehyde and propanoid eugenol were selected to explore their modes of action against Candida albicans.

Electron microscopy, flow cytometry and spectroscopic assays were employed to determine the targets of these compounds. Treatment of Candida cells by cinnamaldehyde and eugenol at 0. The binding assays reflected the ability of compounds to bind with the ergosterol. Our findings have suggested that the membrane damaging effects of phenyl aldehyde and propanoids class of compounds is attributed to their ability to inhibit ergosterol biosynthesis and simultaneously binding with ergosterol.

Indirect or secondary action of these compounds on cell wall is also expected as revealed by electron microscopic studies. The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S.

The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. Septins and actin were mislocalized, and cell wall synthesis was very abnormal, including long projections of cell wall into the cytoplasm. These results expand the roles of eisosomes by demonstrating that Sur7 is needed for proper plasma membrane organization and cell wall synthesis.

A conserved Cys motif in the first extracellular loop of fungal Sur7 proteins is similar to a characteristic motif of the claudin proteins that form tight junctions in animal cells , suggesting a common role for these tetraspanning membrane proteins in forming specialized plasma membrane domains. Plasma membrane-cell wall connections: Tradescantia virginiana leaf epidermal cells were plasmolysed by sequential treatment with 0. Plasmolysis revealed adhesion of the plasma membrane to the cell wall at sites coinciding with cytoskeletal arrays involved in the polarisation of cells undergoing asymmetric divisions--cortical actin patch--and in the establishment and maintenance of the division site--preprophase band of microtubules and filamentous F actin.

The majority of cells retained adhesions at the actin patch throughout mitosis. After the breakdown of the nuclear envelope, plasmolysis had a dramatic effect on spindle orientation, cell plate formation, and the plane of cytokinesis. Spindles were rotated at abnormal angles including tilted into the plane of the epidermis.

Cell plates formed but were quickly replaced by vacuole-like intercellular compartments containing no Tinopal-stainable cell wall material. This compartment usually opened to the apoplast at one side, and cytokinesis was completed by the furrow extending across the protoplast. This atypical cytokinesis was facilitated by a phragmoplast containing microtubules and F-actin. Progression of the furrow was unaffected by 25 micrograms of cytochalasin B per ml but inhibited by 10 microM oryzalin.

Phragmoplasts were contorted and misguided and cytokinesis prolonged, indicating severe disruption to the guidance mechanisms controlling phragmoplast expansion. The mechanism of human T-lymphocyte activation by the pathogenic yeast Cryptococcus neoformans has not been established.

Previous investigations have suggested that C. Because of the potential importance of the mechanism of T- cell activation for our understanding of the immune response to C. The T- cell response to C. However, allogeneic cells were sufficient for accessory cell function, indicating that the response was not major histocompatibility complex restricted.

The percentage of T cells in the cell cycle was higher than that with the recall antigen tetanus toxoid but lower than that with the mitogenic lectin phytohemagglutinin A or the superantigen Staphylococcus enterotoxin B. Compared to the case for most mitogens or superantigens, the proliferative response is late and the number of T cells that enter the cell cycle and the precursor frequency are low, indicating that the mitogenic effect is modest.

However, the mitogenic effect of C. Crystal structure of MraY, an essential membrane enzyme for bacterial cell wall synthesis. MraY phospho-MurNAc-pentapeptide translocase is an integral membrane enzyme that catalyzes an essential step of bacterial cell wall biosynthesis: MraY has long been considered a promising target for the development of antibiotics, but the lack of a structure has hindered mechanistic understanding of this critical enzyme and the enzyme superfamily in general.

Single- wall carbon nanotube-based proton exchange membrane assembly for hydrogen fuel cells. A membrane electrode assembly MEA for hydrogen fuel cells has been fabricated using single- walled carbon nanotubes SWCNTs support and platinum catalyst. Scanning electron microscopy and Raman spectroscopy showed that the nanotubes and the platinum retained their nanostructure morphology on the carbon fiber surface.

Electrochemical impedance spectroscopy EIS revealed that the carbon nanotube-based electrodes exhibited an order of magnitude lower charge-transfer reaction resistance R ct for the hydrogen evolution reaction HER than did the commercial carbon black CB -based electrodes. Relative contribution of the cell wall , cytoplasmic membrane , and cytoplasm to the gram-positive characteristic of Bacillus megaterium.

Protoplasts of Bacillus megaterium were confirmed as being gram-negative, as reported by Gerhardt et al. Bacterial strains living in the environment must cope with the toxic compounds originating from humans production. Surface bacterial structures, cell wall and cytoplasmic membrane , surround each bacterial cell and create selective barriers between the cell interior and the outside world. They are a first site of contact between the cell and toxic compounds.

Organic pollutants are able to penetrate into cytoplasmic membrane and affect membrane physiological functions. Bacteria had to evolve adaptation mechanisms to counteract the damage originated from toxic contaminants and to prevent their accumulation in cell. This review deals with various adaptation mechanisms of bacterial cell concerning primarily the changes in cytoplasmic membrane and cell wall.

Low energy consumption of cell adaptation is required to provide other physiological functions. Bacteria able to survive in toxic environment could help us to clean contaminated areas when they are used in bioremediation technologies. Proteomics of plasma membranes from poplar trees reveals tissue distribution of transporters, receptors, and proteins in cell wall formation. ATP-binding cassette transporters all members of subfamilies B, C, and G and receptor-like kinases four subfamilies were two of the largest protein families found, and the members of these two families showed pronounced tissue distribution.

Leaf plasma membranes were characterized by a very high proportion of transporters, constituting almost half of the integral proteins. Proteins involved in cell wall synthesis such as cellulose and sucrose synthases and membrane trafficking were most abundant in xylem plasma membranes in agreement with the role of the xylem in wood formation.

Twenty-five integral proteins and 83 soluble proteins were exclusively found in xylem plasma membranes , which identifies new candidates associated with cell wall synthesis and wood formation. Among the proteins uniquely found in xylem plasma membranes were most of the enzymes involved in lignin biosynthesis, which suggests that they may exist as a complex linked to the plasma membrane. A laser microsurgical method of cell wall removal allows detection of large-conductance ion channels in the guard cell plasma membrane.

Application of patch clamp techniques to higher-plant cells has been subject to the limitation that the requisite contact of the patch electrode with the cell membrane necessitates prior enzymatic removal of the plant cell wall. Because the wall is an integral component of plant cells , and because cell-wall -degrading enzymes can disrupt membrane properties, such enzymatic treatments may alter ion channel behavior.

We compared ion channel activity in enzymatically isolated protoplasts of Vicia faba guard cells with that found in membranes exposed by a laser microsurgical technique in which only a tiny portion of the cell wall is removed while the rest of the cell remains intact within its tissue environment. These data indicate that ion channels are present in plant membranes that are not detected by conventional patch clamp techniques involving the production of individual plant protoplasts isolated from their tissue environment by enzymatic digestion of the cell wall.

Given the large conductances of the channels revealed by laser-assisted patch clamping, we hypothesize that these channels play a significant role in the regulation of ion content and electrical signalling in guard cells. Interactions between plant cell walls and plasma membranes are essential for cells to function properly, but the molecules that mediate the structural continuity between wall and membrane are unknown.

Some of these interactions, which are visualized upon tissue plasmolysis in Arabidopsis Arabidopsis thaliana , are disrupted by the RGD arginine-glycine-aspartic acid tripeptide sequence, a characteristic cell adhesion motif in mammals. To identify peptide sequences that specifically bind the RGD motif of the IPI-O protein and potentially play a role in receptor recognition, we screened a heptamer peptide library displayed in a filamentous phage and selected two peptides acting as inhibitors of the plasma membrane RGD-binding activity of Arabidopsis.

Moreover, the two peptides also disrupted cell wall -plasma membrane adhesions. Sequence comparison of the RGD-binding peptides with the Arabidopsis proteome revealed 12 proteins containing amino acid sequences in their extracellular domains common with the two RGD-binding peptides. Eight belong to the receptor-like kinase family, four of which have a lectin-like extracellular domain. The lectin domain of one of these, At5g, recognized the RGD motif both in peptides and proteins.

These results imply that lectin receptor kinases are involved in protein-protein interactions with RGD-containing proteins as potential ligands, and play a structural and signaling role at the plant cell surfaces. Lectin receptor kinases participate in protein-protein interactions to mediate plasma membrane-cell wall adhesions in Arabidopsis.

High affinity RGD-binding sites at the plasma membrane of Arabidopsis thaliana links the cell wall. The heptapeptide Tyr-Gly-Arg-Gly-Asp-Ser-Pro containing the sequence Arg-Gly-Asp RGD--the essential structure recognised by animal cells in substrate adhesion molecules was tested on epidermal cells of onion and cultured cells of Arabidopsis upon plasmolysis.

Dramatic changes were observed on both types of cells following treatment: Protoplasts isolated from Arabidopsis cells agglutinate in the presence of ProNectinF, a genetically engineered protein of 72 kDa containing 13 RGD sequences: The addition of the RGD-heptapeptide disrupted the adhesion between the protoplasts. Purified plasma membrane from Arabidopsis cells exhibits specific binding sites for the iodinated RGD-heptapeptide. The binding is saturable, reversible, and two types of high affinity sites Kd1 approximately 1 nM, and Kd2 approximately 40 nM can be discerned.

Competitive inhibition by several structurally related peptides and proteins noted the specific requirement for the RGD sequence. Thus, the RGD-binding activity of Arabidopsis fulfils the adhesion features of integrins, i. Cell wall accumulation of fluorescent proteins derived from a trans-Golgi cisternal membrane marker and paramural bodies in interdigitated Arabidopsis leaf epidermal cells. In most dicotyledonous plants, leaf epidermal pavement cells develop jigsaw puzzle-like shapes during cell expansion.

Therefore, visualization of membrane trafficking in leaf pavement cells should contribute an understanding of the mechanism of plant cell morphogenesis. To reveal membrane trafficking in pavement cells , we observed monomeric red fluorescent protein-tagged rat sialyl transferases, which are markers of trans-Golgi cisternal membranes , in the leaf epidermis of Arabidopsis thaliana.

Quantitative fluorescence imaging techniques and immunoelectron microscopic observations revealed that accumulation of the red fluorescent protein occurred mostly in the curved regions of pavement cell borders and guard cell ends during leaf expansion.

Transmission electron microscopy observations revealed that apoplastic vesicular membrane structures called paramural bodies were more frequent beneath the curved cell wall regions of interdigitated pavement cells and guard cell ends in young leaf epidermis.

In addition, pharmacological studies showed that perturbations in membrane trafficking resulted in simple cell shapes. These results suggested possible heterogeneity of the curved regions of plasma membranes , implying a relationship with pavement cell morphogenesis.

An enzyme complex responsible for the TUA chain biosynthesis was purified and characterized. TUAS displays hydrophobic properties and is found primarily associated with the cytoplasmic membrane. The purified TUAS contains carotinoids and lipids. TUAS activity is diminished by phospholipase digestion. We propose that TUAS serves as a multitasking polysaccharide assembling station on the bacterial membrane. Actin filaments regulate the adhesion between the plasma membrane and the cell wall of tobacco guard cells.

During the opening and closing of stomata, guard cells undergo rapid and reversible changes in their volume and shape, which affects the adhesion of the plasma membrane PM to the cell wall CW. The dynamics of actin filaments in guard cells are involved in stomatal movement by regulating structural changes and intracellular signaling. However, it is unclear whether actin dynamics regulate the adhesion of the PM to the CW.

In this study, we investigated the relationship between actin dynamics and PM-CW adhesion by the hyperosmotic-induced plasmolysis of tobacco guard cells.

We found that actin filaments in guard cells were depolymerized during mannitol-induced plasmolysis. However, treatment with latrunculin B alleviated the RGDS peptide-induced plasmolysis and endocytosis.

Our results reveal that the actin depolymerization is involved in the regulation of the PW-CW adhesion during hyperosmotic-induced plasmolysis in tobacco guard cells.

In this study, a series of nanocomposite membranes were fabricated with the PVA-influenced functionalized MWCNTs reinforced into the Nafion polymer matrix by a solution casting method. After that, the nanocomposite membranes were characterized by thermo-gravimetric analysis TGA to observe the thermal enhancement caused by effective cross-linking between the f-MWCNTs with the composite polymer matrixes.

Diffusion of nitric oxide across cell membranes of the vascular wall requires specific connexin-based channels. NO is generated within cells and frequently must be transferred to responsive neighboring cells , as occurs in the endothelium-dependent relaxation of smooth muscle cells observed in blood vessels.

It is thought that NO diffuses freely across cell membranes , but it may also permeate through low resistant membrane pathways. Here, we describe the participation of connexin Cx -formed channels in the NO transport across cell membranes and between endothelial and smooth muscle cells. We used a water-soluble NO donor of high molecular weight S-nitrosylated albumin, BSA-NO that does not permeate through cell membranes or Cx-based channels and the NO-sensitive dye 4,5-diaminofluorescein diacetate to detect changes of intracellular NO concentration.

We found that NO generated in the extracellular space was not detected intracellularly in Cx-deficient HeLa cells , suggesting that cell membrane represents a significant diffusion barrier for NO transfer. In contrast, NO closed hemichannels of HeLa-Cx32 cells , which otherwise are permeable to NO if are opened by a divalent cation-free extracellular solution.

Consistent with this, blockade of Cx-based channels abolished the myoendothelial NO transfer and associated NO-dependent vasodilation induced by acethylcholine.

These results indicate that Cx-based channels play a key role in the NO-dependent tonic control of vascular function and may direct the NO signal to specific targets, which provides a novel mechanistic basis for the critical role of Cxs in cell-cell communication in the vessel wall. Perturbation of the Staphylococcus aureus cytoplasmic membrane CM is felt to play a key role in the microbicidal mechanism of many antimicrobial peptides APs.

We hypothesized that the relationships between MP and killing may differ for distinct APs. Four APs with different structure-activity relationships were examined: MP was quantified fluorometrically by calcein release.

All APs tested, except polymyxin B, caused concentration-dependent MP and killing of whole cells , but not of protoplasts. The reduced AP susceptibility of protoplasts was associated with increased cardiolipin and lysyl-phosphatidylglycerol content and reduced fluidity of their CMs. Collectively, these results indicate that i structurally distinct APs likely exert their staphylocidal effects by differing mechanisms, ii MP is not the sole event leading to AP-induced staphylocidal activity, iii a complex interrelationship exists between the CM and CW in AP-induced killing, and iv liposomes modeled upon whole cell or protoplast CMs can recapitulate the respective susceptibilities to killing by distinct APs.

Peptidoglycan is the major component of the cell envelope of virtually all bacteria. It has structural roles and acts as a selective sieve for molecules from the outer environment. Peptidoglycan synthesis is therefore one of the most important biogenesis pathways in bacteria and has been studied extensively over the last twenty years. The pathway starts in the cytoplasm, continues in the cytoplasmic membrane and finishes in the periplasmic space, where the precursor is polymerized into the peptidoglycan layer.

A number of proteins involved in this pathway, such as the Mur enzymes and the penicillin binding proteins PBPs , have been studied and regarded as good targets for antibiotics. The present review focuses on the membrane steps of peptidoglycan synthesis that involve two enzymes, MraY and MurG, the inhibitors of these enzymes and the inhibition mechanisms. We also discuss the challenges of targeting these two cytoplasmic membrane associated proteins in bacterial cells and the perspectives on how to overcome the issues.

Knockout of the alanine racemase gene in Aeromonas hydrophila HBNUAh01 results in cell wall damage and enhanced membrane permeability. This study focused on the alanine racemase gene alr-2 , which is involved in the synthesis of d-alanine that forms the backbone of the cell wall. When the mutant was supplemented with d-alanine, growth was unaffected; deprivation of d-alanine caused the growth arrest of the starved mutant cells , but not cell lysis. No alanine racemase activity was detected in the culture of the mutant.

Additionally, a membrane permeability assay showed increasing damage to the cell wall during d-alanine starvation. No such damage was observed in the wild type during culture. Scanning and transmission electron microscopy analyses revealed deficiencies of the cell envelope and perforation of the cell wall. Leakage of UV-absorbing substances from the mutants was also observed.

Thus, the partial viability of the mutants and their independence of d-alanine for growth indicated that inactivation of alr-2 does not impose an auxotrophic requirement for d-alanine.

Effect of chirality and length on the penetrability of single- walled carbon nanotubes into lipid bilayer cell membranes. The ability of carbon nanotubes to enter the cell membrane acting as drug-delivery vehicles has yielded a plethora of experimental investigations, mostly with inconclusive results because of the wide spectra of carbon nanotube structures. Because of the virtual impossibility of synthesizing CNTs with distinct chirality, we report a parametric study on the use of molecular dynamics to provide better insight into the effect of the carbon nanotube chirality and the aspect ratio on the interaction with a lipid bilayer membrane.

The simulation results indicated that a single- walled carbon nanotube utilizes different time-evolving mechanisms to facilitate their internalization within the membrane. These mechanisms comprise both penetration and endocytosis. It was observed that carbon nanotubes with higher aspect ratios penetrate the membrane faster whereas shorter nanotubes undergo significant rotation during the final stages of endocytosis. Furthermore, nanotubes with lower chiral indices developed significant adhesion with the membrane.

This adhesion is hypothesized to consume some of the carbon nanotube energy, thus resulting in longer times for the nanotube to translocate through the membrane. Combined effect of synthetic enterocin CRL35 with cell wall , membrane -acting antibiotics and muranolytic enzymes against Listeria cells.

To evaluate the inhibition effectiveness of enterocin CRL35 in combination with cell wall , membrane -acting antibiotics and muranolytic enzymes against the foodborne pathogen Listeria. Synthetic enterocin CRL35 alone and in combination with monensin, bacitracin, gramicidin, mutanolysin and lysozyme were used in this study.

Antibiotics showed positive interactions with the bacteriocin in both strains tested. On the other hand, when mutanolysin and enterocin CRL35 were added to resting cells in a buffer system, the lytic effect of mutanolysin was enhanced.

However, the addition of mutanolysin showed no effect on the growth of L. Moreover, mutanolysin allowed the overgrowth of L. Based on our results, we conclude that the combination of synthetic enterocin CRL35 with some antibiotics is effective against L.

The effectiveness of the combination of synthetic enterocin CRL35 with muramidases seems to depend on complex environments, and more detailed studies need to be performed to elucidate this issue. Enterocin CRL35 represents a promising agent that not only can ensure the quality and safety of food but it can also be combined with several antimicrobial agents important in the medical field. Deciphering the Metabolism of Undecaprenyl-Phosphate: During the biogenesis of bacterial cell-wall polysaccharides, such as peptidoglycan, cytoplasmic synthesized precursors should be trafficked across the plasma membrane.

This essential process requires a dedicated lipid, undecaprenyl-phosphate that is used as a glycan lipid carrier. The sugar is linked to the lipid carrier at the inner face of the membrane and is translocated toward the periplasm, where the glycan moiety is transferred to the growing polymer.

Undecaprenyl-phosphate originates from the dephosphorylation of its precursor undecaprenyl-diphosphate, with itself generated by de novo synthesis or by recycling after the final glycan transfer.

Undecaprenyl-diphosphate is de novo synthesized by the cytosolic cis-prenyltransferase undecaprenyl-diphosphate synthase, which has been structurally and mechanistically characterized in great detail highlighting the condensation process.

In contrast, the next step toward the formation of the lipid carrier, the dephosphorylation step, which has been overlooked for many years, has only started revealing surprising features.

In contrast to the previous step, two unrelated families of integral membrane proteins exhibit undecaprenyl-diphosphate phosphatase activity: BacA and members of the phosphatidic acid phosphatase type 2 super-family, raising the question of the significance of this multiplicity. Moreover, these enzymes establish an unexpected link between the synthesis of bacterial cell-wall polymers and other biological processes.

In the present review, the current knowledge in the field of the bacterial lipid carrier, its mechanism of action, biogenesis, recycling, regulation, and future perspective works are presented.

Plants are able to generate large leaf surfaces that act as two-dimensional solar panels with a minimum investment in building material, thanks to a hydrostatic skeleton.

This requires high intracellular pressures up to 1 MPa , which depend on the presence of strong cell walls. The walls of growing cells also called primary walls , are remarkably able to reconcile extreme tensile strength up to MPa with the extensibility necessary for growth.

All walled organisms are confronted with this dilemma - the need to balance strength and extensibility - and bacteria, fungi and plants have evolved independent solutions to cope. In this Primer, we discuss how plant cells have solved this problem, allowing them to support often very large increases in volume and to develop a broad variety of shapes Figure 1A,B,D.

This shape variation reflects the targeted deposition of wall material combined with local variations in cell-wall extensibility, processes that remain incompletely understood. Once the cell has reached its final size, it can lay down secondary wall layers, the composition and architecture of which are optimized to exert specific functions in different cell types Figure 1E-G.

Specialized secondary walls , such as those constituting seed mucilage, are stored in a dehydrated form in seedcoat epidermis cells and show rapid swelling upon hydration of the seed. Other walls , in particular in reserve tissues, can accommodate large amounts of storage polysaccharides, which can be easily mobilized as a carbon source. Physiological and transcriptional responses of Saccharomyces cerevisiae to d-limonene show changes to the cell wall but not to the plasma membrane.

Monoterpenes can, upon hydrogenation, be used as light-fraction components of sustainable aviation fuels. Fermentative production of monoterpenes in engineered microorganisms, such as Saccharomyces cerevisiae, has gained attention as a potential route to deliver these next-generation fuels from renewable biomass.

However, end product toxicity presents a formidable problem for microbial synthesis. Due to their hydrophobicity, monoterpene inhibition has long been attributed to membrane interference, but the molecular mechanism remains largely unsolved. We found no alterations in membrane fluidity, structural membrane integrity, or fatty acid composition after the solvent challenge. A 4-fold increase in the mean fluorescence intensity per cell using calcofluor white stain and increased sensitivity to cell wall -degrading enzymes demonstrated that limonene disrupts cell wall properties.

Global transcript measurements confirmed the membrane integrity observations by showing no upregulation of ergosterol or fatty acid biosynthesis pathways, which are commonly overexpressed in yeast to reinforce membrane rigidity during ethanol exposure. This is the first report demonstrating that cell wall , rather than plasma membrane , deterioration is the main source of monoterpene inhibition.

We show that limonene can alter the structure and function of the cell wall , which has a clear effect on cytokinesis. Proteins in the cell wall and membrane of Cryptococcus neoformans stimulate lymphocytes from both adults and fetal cord blood to proliferate. Cryptococcus neoformans is an encapsulated yeast that infects patients who have defective cell -mediated immunity, including AIDS, but rarely infects individuals who have intact cell -mediated immunity.

Studies of the immune response to C. The goal of this study was to separate C. The lymphocyte response to fungal culture medium, whole organisms, disrupted organisms, and the yeast intracellular fraction or cell wall and membrane was studied by determining thymidine incorporation and by determining the number of lymphocytes at various times after stimulation. The cell wall and membrane of C.

The optimal response occurred on day 7 of incubation, with 4 x 10 5 peripheral blood mononuclear cells per well and with 13 microg of cryptococcal protein per ml. The number of lymphocytes increased with time in culture, indicating that thymidine incorporation was accompanied by proliferation. Proteinase K treatment of the cell wall and membrane abrogated lymphocyte proliferation, indicating that the molecule was a protein. At least 18 discrete bands were resolved from the cell wall and membrane.

Since a large percentage of healthy adults responded to the cryptococcal cell wall and membrane , a mitogenic effect was investigated by testing proliferation of fetal cord blood. An investigation into plasmolysis in the oomycete Achlya bisexualis reveals that membrane-wall attachment points are sensitive to peptides containing the sequence RGD and that cell wall deposition can occur despite retraction of the protoplast.

The structure and function of membrane-wall attachment sites in walled cells , and how these relate to animal focal adhesions, is an area that is poorly understood. In view of this, we investigated how membrane-wall attachments that form upon plasmolysis, respond to peptides that disrupt animal focal adhesions. The degree of cytoplasmic disruption during plasmolysis was also investigated. Upon hyperosmotic challenge, the protoplast in hyphae of the oomycete Achlya bisexualis typically retracted incompletely due to membrane-wall attachments.

The inclusion, in the plasmolysing solution, of peptides containing the sequence RGD disrupted these attachments in a dose-dependent manner. In some hyphae, protoplast retraction stopped temporarily at attachment points - upon resumption of retraction, material was left that traced the outline of the static protoplast. Staining of this material with fluorescence brightener indicated the presence of cellulose, which suggests that wall deposition was able to occur despite plasmolysis.

The F-actin cytoskeleton was disrupted during plasmolysis; peripheral F-actin staining was observed, but there was no distinct F-actin cap; staining was more diffuse; and there were fewer plaques compared with nonplasmolysed hyphae.

Our data indicate that membrane-wall attachment points are sensitive to RGD-containing peptides and that wall deposition continues despite protoplast retraction and F-actin disruption. Genome-wide reprogramming of regulatory networks, transport, cell wall and membrane biogenesis during arbuscular mycorrhizal symbiosis in Lotus japonicus. As a consequence of the fungal colonization and of the deep reorganization shown by arbusculated cells , important impacts on root transcriptome are expected.

Induction of a subset 24 genes of these was tested and confirmed by qRT-PCR, and transcript location in arbusculated cells was demonstrated for seven genes using laser-dissected cells. Improving the electro-transformation efficiency of Corynebacterium glutamicum by weakening its cell wall and increasing the cytoplasmic membrane fluidity. To improve the transformation efficiency of Corynebacterium glutamicum cells with heterogenous plasmid DNA and single-strand DNA ssDNA using a methodology based on electro-transformation.

A semicomplex hypertonic medium was selected with addition of glycine and DL-threonine to weaken cell walls and addition of Tween 80 and isonicotinic acid hydrazide to increase cytoplasmic membrane fluidity. Their contents were optimized by response surface methodology. Cell growth, electro-transformation buffer, and transformation protocol were also optimized.

Temporary heating inactivation of the host restriction enzyme showed a significant effect. Finally, a high transformation efficiency of 3.

The results shed light on the application in functional genomics and genome editing of C. The rice dynamin-related protein DRP2B mediates membrane trafficking, and thereby plays a critical role in secondary cell wall cellulose biosynthesis.

Membrane trafficking between the plasma membrane PM and intracellular compartments is an important process that regulates the deposition and metabolism of cell wall polysaccharides. Dynamin-related proteins DRPs , which function in membrane tubulation and vesiculation are closely associated with cell wall biogenesis.

However, the molecular mechanisms by which DRPs participate in cell wall formation are poorly understood. Consistent with the expression of BC3 in mechanical tissues, the bc3 mutation reduces mechanical strength, which results from decreased cellulose content and altered secondary wall structure.

Subcellular localization of fluorescence-tagged OsDRP2B and several compartment markers in protoplast cells showed that this protein not only lies at the PM and the clathrin-mediated vesicles, but also is targeted to the trans-Golgi network TGN. An FM uptake assay in transgenic plants that express green fluorescent protein-tagged OsDRP2B verified its involvement in an endocytic pathway.

All of these findings lead us to conclude that OsDRP2B participates in the endocytic pathway, probably as well as in post-Golgi membrane trafficking.

Mutation of OsDRP2B disturbs the membrane trafficking that is essential for normal cellulose biosynthesis of the secondary cell wall , thereby leading to inferior mechanical properties in rice plants. Enzymatic biofuel cells EBFCs utilize enzymes to convert chemical energy present in renewable biofuels into electrical energy and have shown much promise in the continuous powering of implantable devices.

Currently, however, EBFCs are greatly limited in terms of power and operational stability with a majority of reported improvements requiring the inclusion of potentially toxic and unstable electron transfer mediators or multicompartment systems separated by a semipermeable membrane resulting in complicated setups. Glucose oxidase and bilirubin oxidase were physically adsorbed onto these electrodes to form anodes and cathodes, respectively, and the EBFC produced power densities up to 0.

Further, the electrodes were rejuvenated by a simple wash and reloading procedure. We postulate these porous and ultrahigh surface area electrodes will be useful for biosensing applications, and will allow reuse of EBFCs. In this study the elastic spring constant of the yeast cell wall is probed with the atomic force microscope AFM under variable conditions. Cells were sequentially analyzed in rich growth medium YPD , a 0. Cells in late log phase, which have variable diameters within three to five microns, were immobilized on a patterned silicon substrate with holes approximately 3.

Force curves were taken moving laterally across the cell in one dimension after exposure to each medium. Spring constants of the cells , calculated from force curves, displayed a positional dependency and marked differences in high osmolarity medium and after the injection of sodium azide.

Common ragweed Ambrosia artemisiifolia is an invasive alien species in Europe producing pollen that causes severe allergic disease in susceptible individuals.

Ragweed plants could further invade European land with climate and land-use changes. However, airborne pollen evolution depends not only on plant invasion, but also on pollen production, release and atmospheric dispersion changes. To predict the effect of climate and land-use changes on airborne pollen concentrations, we used two comprehensive modelling frameworks accounting for all these factors under high-end and moderate climate and land-use change scenarios.

We estimate that by airborne ragweed pollen concentrations will be about 4 times higher than they are now, with a range of uncertainty from 2 to 12 largely depending on the seed dispersal rate assumptions. About a third of the airborne pollen increase is due to on-going seed dispersal, irrespective of climate change.

The remaining two-thirds are related to climate and land-use changes that will extend ragweed habitat suitability in northern and eastern Europe and increase pollen production in established ragweed areas owing to increasing CO2. Therefore, climate change and ragweed seed dispersal in current and future suitable areas will increase airborne pollen concentrations, which may consequently heighten the incidence and prevalence of ragweed allergy. Full Text Available Since the common ragweed , Ambrosia artemisiifolia , which was introduced from North America has also been found in Bavaria in larger stocks and has an increasing tendency to spread.

After receiving the report of the Bavarian Ministry of Health, the Bavarian Parliament addressed the implications for health. There was consensus across all political groups to combat the plant. The 96 district administration authorities, which each have a trained ragweed officer, report to the registration office on new verified ragweed locations with more than plants. The reports of common ragweed stands are filed by citizens or through research by the district administration authorities, who are also responsible for supporting the fight against stocks.

On behalf of the Bavarian Ministry of Health, the Working Group Biodiversity monitors the situation and finds many new locations. Since , new common ragweed stocks were registered. After control measures there are currently known remaining stocks. Since , however, the populated area has tripled. This means that the control measures need further improvement. This is especially true for the common ragweed stocks along roadsides where the plants have increased massively in recent years.

Sustainable control has proved to be particularly difficult. Ragweed -induced allergic rhinoconjunctivitis: Ragweed -induced allergic rhinoconjunctivitis has long been seen as a major immunologic condition in Northern America with high exposure and sensitization rates in the general population. The invasive occurrence of ragweed A. Possible explanations for its worldwide spread are climate change and urbanization, as well as pollen transport over long distances by globalized traffic and winds.

Due to the increasing disease burden worldwide, and to the lack of a current and comprehensive overview, this study aims to review the current and emerging treatment options for ragweed -induced rhinoconjunctivitis.

Sound clinical evidence is present for the symptomatic treatment of ragweed -induced allergic rhinoconjunctivitis with oral third-generation H1-antihistamines and leukotriene antagonists. The topical application of glucocorticoids has also been efficient in randomized controlled clinical trials. Combined approaches employing multiple agents are common.

The mainstay of causal treatment to date, especially in Northern America, is subcutaneous immunotherapy with the focus on the major allergen, Amb a 1. Beyond this, growing evidence from several geographical regions documents the benefit of sublingual immunotherapy. Future treatment options promise more specific symptomatic treatment and fewer side effects during causal therapy.

Novel antihistamines for symptomatic treatment are aimed at the histamine H3-receptor. New adjuvants with toll-like receptor 4 activity or the application of the monoclonal anti-immunoglobulin E antibody, omalizumab, are supposed to enhance conventional immunotherapy. An approach targeting toll-like receptor 9 by. Full Text Available The European Union handed over the regulation of common ragweed Ambrosia artemisiifolia to the member states. Austrian administration started to ask for control measures, i.

Any sustainable control measure must focus on the reduction of seeds produced by the annual ragweed. Seed bank dimension of ragweed turned out to be a good evaluation tool for any control measure. To evaluate the importance of different spreading mechanisms of dispersal, a need for serious figures can be stated.

Based on our seed trap experiments and comparable slip stream experiments by German botanists, the efficiency of vehicles in spreading ragweed over long distances was low. However, machines used by road services cutter, moulder turned out to spread thousands of seeds. Besides, there is serious indication that trucking agricultural food and seeds over long distances is relevant for ragweed seed dispersal. Dispersal of thousands of ragweed seeds from contaminated agricultural fields to fields not yet infested is caused by harvesters and other agricultural machines.

Regulations to reduce the ragweed load in traded agricultural goods are to be implemented in future. Small populations of ragweed should be simply uprooted and composted as long as they bear no flowers. Various possibilities are known for control of common ragweed in agricultural fields with mechanical and chemical methods. Limits are set in sunflowers because sunflower and ragweed are botanically related.

The legal obligation of reporting and control — introduced in Switzerland a couple of years ago — allowed the development of specific distribution maps and enhanced the quality of control measures. Facts and figures from the Canton of Geneva prove that the ragweed invasion has been stopped, but the species is not eradicated.

The results of Geneva represent the results of good ragweed control in the whole country. Beside agriculture, traffic infrastructure, building sites, gravel pits and urban park and garden areas are sensible to ragweed invasion.

The responsibility of individuals helps to improve control efficiency even if financial funds are small. A sustainable control success depends on the efficiency to hamper seed production. The reduction of pollen quantity in the air in a long term is part of the earnings for the control effort.

Actually, the publicity of common ragweed is fed by specialist information and its distribution in the media. It would be an interesting task to develop in our fast moving era an awareness level comparable to that of the stinging nettle.

Effect of heavy metals on seed germination and seedling growth of common ragweed and roadside ground cover legumes. It creates empty niches vulnerable to weed establishment such as common ragweed Ambrosia artemisiifolia. We hypothesized that heavy metal stresses may drive such species shifts along roadside edges.

A growth chamber experiment was conducted to assess effects of metals Zn, Pb, Ni, Cu, and Cd on germination and seedling behaviors of roadside weed A. All metals inhibited T. Low levels of Pb and Ni promoted germination initiation of A.

Metal additions hindered seedling growth of all test species, and the inhibitory effect on the belowground growth was greater than on the aboveground growth. Seedling mortality was lowest in A. In conclusion, the successful establishment of A. The findings also revealed that L. Full Text Available Identifying the sensitive habitats with high invasibility is critical for management of biological invasion.

Ragweed Ambrosia artemisiifolia Linn. The experiment took ragweek as a model invader to reveal the community invisibility of different habitats. The results suggested that the presence of native species had strong negative effects on the performance of the invader species.

The presence of native species occupied the niche space and left few empty niches for the colonization of the invaders. The results revealed that planting native species in bare soils, and maintaining the native communities with high diversity, was effective strategies to control the invasion of exotic species.

The present situation of the plant was analyzed in Qinhuangdao region, and the new campus was taken as an example to inves-tigate the effects of human activity disturbance on A. The invasiveness of A. In present, the plant was a community construction species in this region, and showed no invasion.

The investigated results showed that A. However, in the habitat disturbed by human activities, the plant had relatively high advantage. Therefore, excessive human activity disturbance should be prevented to control the invasive plant, by which to protect the local ecological environment. Ragweed subpollen particles of respirable size activate human dendritic cells. Full Text Available Ragweed Ambrosia artemisiifolia pollen grains, which are generally considered too large to reach the lower respiratory tract, release subpollen particles SPPs of respirable size upon hydration.

In this study, we examined whether exposure to SPPs initiates the activation of human monocyte-derived dendritic cells moDCs. Collectively, our data suggest that inhaled ragweed SPPs are fully capable of activating dendritic cells DCs in the airways and SPPs' NAD PH oxidase activity is involved in initiation of adaptive immune responses against innocuous pollen proteins.

Characterizing restriction enzyme-associated loci in historic ragweed Ambrosia artemisiifolia voucher specimens using custom-designed RNA probes. Population genetic studies of non-model organisms frequently employ reduced representation library RRL methodologies, many of which rely on protocols in which genomic DNA is digested by one or more restriction enzymes.

However, because high molecular weight DNA is recommended for these protocol Ambrosia is a kind of invasive alien weed, whose invasion not only threatens native biodiversity and ecosystems, but also causes considerable economic loss. In order to control the damage of Ambrosia effectively, on the basis of introducing mechanical, chemical and biological control methods, the insufficiencies of them were clarified and an integrated control measure was proposed.

Exotic plant invasion presents a serious threat to native ecosystem structure and function. Little is known about the role of soil microbial communities in facilitating or resisting the spread of invasive plants into native communities. The purpose of this research is to understand how the invasive annual plantAmbrosiaartemisiifoliaL. The soil characteristics of different areas invaded by A.

Greenhouse experiments were designed to assess the effect ofA. The results showed that the soil organic C content was the highest in heavily invaded sites, the lowest in native plant sites, and intermediate in newly invaded sites.

Soil available N, P and K concentrations in heavily invaded site were 2. Soil pH decreased asA. The soil microbial community structure was clearly separated in the three types of sites, andA. Soil biota of invaded sites inhibits growth of co-occurring plants Galinsoga parvilfora Cav. Results of the present study indicated thatA. Northern ragweed ecotypes flower earlier and longer in response to elevated CO2: Significant changes in plant phenology and flower production are predicted over the next century, but we know relatively little about geographic patterns of this response in many species, even those that potentially impact human wellbeing.

We tested for variation in flowering responses of the allergenic plant, Ambrosia artemisiifolia common ragweed. We hypothesized that northern ecotypes adapted to shorter growing seasons would flower earlier than their southern counterparts, and thus disproportionately allocate carbon gains from CO2 to reproduction.

As predicted, latitude of origin and carbon dioxide level significantly influenced the timing and magnitude of flowering. Reproductive onset occurred earlier with increasing latitude, with concurrent increases in the number of flowers produced. Elevated carbon dioxide resulted in earlier reproductive onset in all ecotypes, which was significantly more pronounced in the northern populations.

We interpret our findings as evidence for ecotypic variation in ragweed flowering time, as well in responses to CO2. Thus, the ecological and human health implications of common ragweed 's response to global change are likely to depend on latitude. We conclude that increased flower production, duration, and possibly pollen output, can be expected in Northeastern United States with rising levels of CO2.

The effects are likely, however, to be most significant in northern parts of the region. The invasive alien species Ambrosia artemisiifolia common or short ragweed is increasing its range in Europe. In the UK and the Netherlands, airborne concentrations of Ambrosia pollen are usually low.

However, more than 30 Ambrosia pollen grains per cubic metre of air above the level capable to trigger allergic symptoms were recorded in Leicester UK and Leiden NL on 4 and 5 September The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the episode could be the result of long distance transport, to identify the potential sources of these pollen grains and to describe the conditions that facilitated this possible long distance transport.

Airborne Ambrosia pollen data were collected at 10 sites in Europe. Back trajectories calculated at Leicester and Leiden show that higher altitude air masses m originated from source areas on the Pannonian Plain and Ukraine. The study indicates that the Ambrosia pollen grains recorded during the episode in Leicester and Leiden were probably not produced by local sources but transported long distances from potential source regions in east Europe, i.

Ambrosia airborne pollen concentration modelling and evaluation over Europe. Native from North America, Ambrosia artemisiifolia L. Common Ragweed is an invasive annual weed introduced in Europe in the mid-nineteenth century. It has a very high spreading potential throughout Europe and releases very allergenic pollen leading to health problems for sensitive persons. Because of its health effects, it is necessary to develop modelling tools to be able to forecast ambrosia air pollen concentration and to inform allergy populations of allergenic threshold exceedance.

To calculate and predict airborne concentrations of ambrosia pollen, a chain of models has been built. The detailed methodology, formulations and input data will be presented. A set of simulations has been performed to simulate airborne concentrations of pollens over long time periods on a large European domain.

Hindcast simulations - driven by ERA-Interim re-analyses are designed to best simulate past periods airborne pollens. The modelled pollen concentrations are calibrated with observations and validated against additional observations. Then, year long historical simulations - are carried out using calibrated ambrosia density distribution and climate model-driven weather in order to serve as a control simulation for future scenarios.

By comparison with multi-annual observed daily pollen counts we have shown that the model captures well the gross features of the pollen. Modelling the introduction and spread of non-native species: Biological invasions are a major driver of global change, for which models can attribute causes, assess impacts and guide management.

However, invasion models typically focus on spread from known introduction points or non-native distributions and ignore the transport processes by which species arrive. Here, we developed a simulation model to understand and describe plant invasion at a continental scale, integrating repeated transport through trade pathways, unintentional release events and the population dynamics and local anthropogenic dispersal that drive subsequent spread.

We used the model to simulate the invasion of Europe by common ragweed Ambrosia artemisiifolia , a globally invasive plant that causes serious harm as an aeroallergen and crop weed.

Simulations starting in accurately reproduced ragweed 's current distribution, including the presence of records in climatically unsuitable areas as a result of repeated introduction. Furthermore, the model outputs were strongly correlated with spatial and temporal patterns of ragweed pollen concentrations, which are fully independent of the calibration data.

The model suggests that recent trends for warmer summers and increased volumes of international trade have accelerated the ragweed invasion. For the latter, long distance dispersal because of trade within the invaded continent is highlighted as a key invasion process, in addition to import from the native range. Biosecurity simulations, whereby transport through trade pathways is halted, showed that effective control is only achieved by early action targeting all relevant pathways.

We conclude that invasion models would benefit from integrating introduction processes transport and release with spread dynamics, to better represent propagule pressure from native sources as well as mechanisms for long-distance dispersal within invaded continents. Ultimately, such integration may facilitate better prediction of spatial and temporal variation in invasion.

Ragweed pollen production and dispersion modelling within a regional climate system, calibration and application over Europe. Its pollen can be transported over large distances and has been recognized as a significant cause of hay fever and asthma D'Amato et al. To simulate production and dispersion of common ragweed pollen, we implement a pollen emission and transport module in the Regional Climate Model RegCM version 4 using the framework of the Community Land Model CLM version 4.

In this online approach pollen emissions are calculated based on the modelling of plant distribution, pollen production, species-specific phenology, flowering probability, and flux response to meteorological conditions. A pollen tracer model is used to describe pollen advective transport, turbulent mixing, dry and wet deposition. The model is then applied and evaluated on a European domain for the period To reduce the large uncertainties notably due to the lack of information on ragweed density distribution, a calibration based on airborne pollen observations is used.

Accordingly a cross validation is conducted and shows reasonable error and sensitivity of the calibration. Resulting simulations show that the model captures the gross features of the pollen concentrations found in Europe, and reproduce reasonably both the spatial and temporal patterns of flowering season and associated pollen concentrations measured over Europe. The model can explain The correlation between simulated and observed daily concentrations time series reaches 0.

Statistical scores show that the model performs better over the central Europe source region where pollen loads are larger and the model is better constrained. From these simulations health risks associated to common ragweed pollen.

The airborne ragweed pollen spectrum was investigated in the air of Ankara, Turkey for aperiod of ten years using a Burkard seven-day volumetric recording trap. In our study period,long distance transported Ambrosia pollen has been registered. Daily pollen levels varied from low to highin Burge's system. In last three years, the pollen concentration of Ambrosia showed a clear increasingtendency. Our results prove that ragweed pollen may be an important threat for ragweed sensitive patientsin Ankara city in near future.

Lifescience Database Archive English. Full Text Available c Spatial and temporal variations in airborne Ambrosia pollen in Europe. The goal of the present study is to provide a baseline for spatial and temporal variations in airborne Ambrosia pollen in Europe that can be used for the management and evaluation of this noxious plant.

The study covers the full range of Ambrosia artemisiifolia L. Airborne Ambrosia pollen data for the principal flowering period of Ambrosia August-September recorded during a year period were obtained from monitoring sites.

The mean sum of daily average airborne Ambrosia pollen and the number of days that Ambrosia pollen was recorded in the air were analysed. The mean and standard deviation SD were calculated regardless of the number of years included in the study period, while trends are based on those time series with 8 or more years of data. The direction of any trends varied locally and reflected changes in sources of the pollen, either in size or in distance from the monitoring station.

Pollen monitoring is important for providing an early warning of the expansion of this invasive and noxious plant. The extraction of exotic plant ragweed Ambrosia artemisiifolia L. It can prevent the extraction of ragweed from inactivation,which could be easily caused by external condition such as illumination and temperature. The microcapsule technique can improve the property of extraction.

The results showed that the morphology of microcapsules was regular and integrated observed under scanning electron microscope SEM. Moreover,the core material was coated with shell material observed by the infrared spectrum analysis with Fourier transform infrared spectroscopy FTIR. The association efficiency and loading capacity of the microcapsules determined by ultraviolet spectrophotometer were The medium diameter was And the results of thermogravimetric analysis TGA demonstrated that the thermal stability of the microcapsules was superior to the core material.

Consequently,the microcapsules with the extraction can avoid the unstable defect of the natural extraction. In addition,the activity was also lengthened by this technique.

The occurrence of Ambrosia pollen in the atmosphere of Northwest Turkey: Ambrosia pollen was first reported as an important allergen in North America at the end of the nineteenth century, and many European countries have recently reported its increasing significance for pollen allergy. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the studied period could be the result of long-distance transport LDT and to identify the potential sources of Ambrosia pollen grains.

The study investigates Ambrosia pollen episodes during the peak term of six yearly periods between and by examining source regions in Ambrosia pollen in Bursa, Turkey. A volumetric trap was used for collecting the pollen samples, and the back-trajectory model was used to identify a potential source of atmospheric Ambrosia pollen. The days when pollen levels exceeded 30 P m-3 were computed, and clusters were shown on the figures. The study indicates that the Ambrosia pollen grains recorded during the episode in Bursa were not produced by local sources but transported long distances from potential source regions around the Azov Sea in Russia and Ukraine, Black Sea region of Turkey, Romania, and Bulgaria.

Note that atmospheric concentrations of Ambrosia pollen exceeded the clinical threshold during 28 days during the investigation period. Taking into consideration the high allergenicity of Ambrosia pollen, the present findings suggest that the number of ragweed -sensitized individuals might increase in the near future in the region. Full Text Available From a medical perspective, introduction and spread of ragweed in Germany are a disaster.

The pollen of the species trigger allergic rhinitis and conjunctivitis that often lead to allergies against food items like celery or spices. In some cases this can lead to allergic asthma that at first appears during the ragweed pollen season in September and October, but can later prevail during the whole year.

In addition, touching the plant can result in contact dermatitis. From a medical point of view, halting the spread of ragweed is important and necessary. Analysis of high allergenicity airborne pollen dispersion: The appearance of ragweed pollen in the air became more frequent in northerly countries. Attention of allergologists and aerobiologists in these countries is focused on the phenomenon that Ambrosia plants found relatively sporadic but the amount of pollen is high in particular days.

Over the latter decade, a matter of particular concern has been Ambrosia pollen, whose appearance in the air is determined by the plants dispersing it and meteorological processes that alter pollen release, dissemination, transport or deposition on surfaces.

Pollen data used in this study were collected in three pollen-trapping sites in Lithuania. The data corresponding to years of pollen monitoring were documented graphically and evaluated statistically. Analysis of the pollen data suggests that although the number of ragweed plants identified has not increased over the latter decade, the total pollen count has been on the increase during the recent period.

The highest atmospheric pollen load is established on the last days of August and first days of September. We have established a regularity exhibiting an increase in ragweed pollen count conditioned by south-eastern winds in Lithuania. The ex-periment took ragweek as a model invader to reveal the community invisibility of different habitats. The results revealed that planting native species in bare soils, and maintaining the native communities.

Plants remember past weather: After extreme dry wet summers or years, pollen production of different taxa may decrease increase substantially. Accordingly, studying effects of current and past meteorological conditions on current pollen concentrations for different taxa have of major importance. The purpose of this study is separating the weight of current and past weather conditions influencing current pollen productions of three taxa.

Two procedures, namely multiple correlations and factor analysis with special transformation are used. The year data sets include daily pollen counts of Ambrosia ragweed , Poaceae grasses and Populus poplar , as well as daily values of four climate variables temperature, relative humidity, global solar flux and precipitation. Multiple correlations of daily pollen counts with simultaneous values of daily meteorological variables do not show annual course for Ambrosia , but do show definite trends for Populus and Poaceae.

Results received using the two methods revealed characteristic similarities. For all the three taxa, the continental rainfall peak and additional local showers in the growing season can strengthen the weight of the current meteorological elements.

However, due to the precipitation, big amount of water can be stored in the soil contributing to the effect of the past climate elements during dry periods. Higher climate sensitivity especially water sensitivity of the herbaceous taxa Ambrosia and Poaceae can be definitely established compared to the arboreal Populus.

Separation of the weight of the current and past weather conditions for different taxa involves practical importance both for health care and agricultural production. Field and greenhouse experiments were conducted during and at Stoneville, MS to determine control of ragweed parthenium with several preemergence PRE and postemergence POST herbicides registered for use in corn, cotton, peanut, rice, and soybean.

Change in Ragweed Pollen Season, Environmental Protection Agency — This figure shows how the length of ragweed pollen season changed at 11 locations in the central United States and Canada between and Ambrosia beetles are being increasingly recognized as significant pests of field-grown ornamental nursery stock. Two species are especially problematic in ornamental nurseries, namely the black stem borer, Xylosandrus germanus, and the granulate ambrosia beetle, Xylosandrus crassiusculus.

Economic analysis of preventing introduction of ragweed in Denmark. Ragweed is an Invasive Alien Species natively growing in North America which is at risk of being introduced in Denmark thru import of bird seeds. The plant produces a high amount of pollen which causes allergy and asthma and is considered a very potent allergy source.

It is estimated that An inordinate fondness for Fusarium: Phylogenetic diversity of fusaria cultivated by Euwallacea ambrosia beetles on avocado and other plant hosts. Ambrosia beetle fungiculture represents one of the most ecologically and evolutionarily successful symbioses. Here we document the evolution of a clade within Fusarium associated with ambrosia beetles in the genus Euwallacea Coleoptera: Is ragweed pollen allergenicity governed by environmental conditions during plant growth and flowering?

However, how genotype and environment contribute to ragweed pollen allergenicity has still to be established. To throw some light on the factors governing allergenicity, in this work ragweed plants from three Regions Canada, France, Italy were grown in both controlled constant and standard environmental conditions seasonal changes in temperature, relative humidity and light.

Pollen from single plants was characterized for its allergenic potency and for the underlying regulation mechanisms by studying the qualitative and quantitative variations of the main isoforms of the major ragweed allergen Amb a 1.

Results showed a statistically higher variability in allergenicity of pollen from standard conditions than from controlled conditions growing plants. This variability was due to differences among single plants, regardless of their origin, and was not ascribed to differences in the expression and IgE reactivity of individual Amb a 1 isoforms but rather to quantitative differences involving all the studied isoforms.

It suggests that the allergenic potency of ragweed pollen and thus the severity of ragweed pollinosis mainly depends on environmental conditions during plant growth and flowering, which regulate the total Amb a 1 content.

Effects of photoperiod and temperature on reproductive diapause in Ophraella communa Coleoptera: Chrysomelidae , a potential biocontrol agent against Ambrosia artemisiifolia.

To investigate the seasonal adaptation strategies of Ophraella communa to new habitats,the effects and regulation mechanisms of photoperiod and temperature on the reproductive diapause in a population collected from Changsha,Hunan were examined. Adults showed obvious reproductive diapause,which was regulated by photoperiod and temperature. The pre-oviposition period was significantly prolonged when the pupae and adults were transferred from long-days to short-days,but the day length influence was not obvious when they were transferred only in the adult stage.

However,the fecundity dropped greatly no matter whether the photoperiod shifted to short-days only in the adult stage or whether the shift occurred in both the pupal and adult stage. The fecundity was extremely low when photoperiod shifted from long-days to short-days in both pupal and adult stages.

This was an indication that the pupal and adult stages were the photoperiod-sensitive stage for adult reproductive diapause. This was especially true for the photoperiod in the pupal stage,which has a distinctly significant regulative effect on reproductive diapause. Additionally,this article also addresses the reason for different photoperiodic response patterns in reproductive diapause induction between the Changsha strain and the Tsukuba strain Japan of O.

Ragweed in France is a rather recent pollen which causes strong allergies on the populations concerned. This pollen, mainly located in the area Rhone-Alpes, extend more and more on totality of France. Indeed, the pollinic data highlight the presence of ragweed on all the territory with very low, as for Brittany, to several hundreds grains in the area of Rhone-Alpes. So four towns of this area have followed closely the extend of this pollen during the year through five pollen-traps 2 for the town of Lyon.

The trap of Lyon I Gerland made it possible to follow temporal the extend of ragweed from to and the increase of the number of grains as that of the number of days with a significant allergic risk.

The study shows also the differences in quantity of pollens, the differences between the daily allergic risks of the five sites, as well as the differences, between the cities, of the number of days when the allergic risk is significant. It is necessary that pollen of ragweed can be followed closely because of its strong allergenic capacity, in the area of Rhone-Alpes, where the plant prevails mainly, but also on the totality of the own territory, this to supervise its evolution and the speed of proliferation of the plant.

Chemical ecology and lure development for redbay ambrosia beetle. The exotic redbay ambrosia beetle, Xyleborus glabratus Eichhoff, has become a serious invasive pest in the U. Female beetles are the primary vectors of a pathogenic fungus Raffaelea lauricola that causes laurel wilt.

This lethal vascular dise Ambrosia beetles associated with laurel wilt of avocado. Redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-boring pest first detected in near Savannah, Georgia. Laurel wilt has since spr The invasive redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-boring pest first detected in the U.

Redbay Ambrosia Beetle xyleborus glabratus eichoff coleoptera: The redbay ambrosia beetle, Xyleborus glabratus Eichoff, and its associated fungus Raffaelea lauricola T.

Together, they cause a vascular wilt disease that is highly destructive to some species in the Lauraceae Fraedrich et al. Xyleborus glabratus is a member of the Chemical ecology of the redbay ambrosia beetle Xyleborus glabratus. The redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-boring pest first detected in the U. Ethanol injection of ornamental trees facilitates testing insecticide efficacy against ambrosia beetles Coleoptera: Exotic ambrosia beetles are damaging pests in ornamental tree nurseries in North America.

The species Xylosandrus crassiusculus Motshulsky and Xylosandrus germanus Blandford are especially problematic. Management of these pests relies on preventive treatments of insecticides. Kumisi Lake , a brackish water body in an active agricultural area, appeared to be the most polluted, whereas the Tbilisi Sea, a freshwater reservoir was the least polluted. High values for fecal indicators in all three lakes in summer and early autumn were revealed.

In our study, total enterococci counts TEC appeared to be a better indicator than either fecal or total coliform counts for the evaluation of fresh and brackish microbial water quality. We found significant correlation between total Vibrio counts and TEC for all three water bodies. Prevalence of somatic coliphages and V.

Particular phytoplankton groups in the lakes responded to the changes of fecal indicators; however, no correlation was observed between dominant zooplankton taxonomic groups and microbial parameters. Lake Erie, the smallest and warmest lake among the Laurentian Great Lakes , is known for its problem of eutrophication and frequent occurrence of harmful cyanobacterial blooms CyanoHABs. One major harmful effect of CyanoHABs is the production of cyanotoxins, especially microcystins.

Field measurements and lab experiments indicate that MC degradation in Lake Erie is mainly carried out by indigenous bacteria. However, our knowledge on taxa involved in this process is very limited. This study aimed to fill this knowledge gap using a culture-dependent approach. Cells were plated on a number of culturing media.

Viruses in subarctic lakes and their impact on benthic and pelagic bacteria. Virus-bacterium interactions were investigated in the pelagic and benthic habitats in a set of lakes along an altitudinal gradient in the subarctic northern Sweden.

Viral and bacterial abundances showed a significant variation between the lakes , with the highest benthic microbial abundances recorded in a high-altitude lake [ m above sea level a. In the pelagic habitat, there was also a distinct difference in microbial abundances between the summer-autumn and the winter sampling occasion. A positive relationship was noted between viruses and bacteria in both the pelagic and the benthic habitats.

Visibly virus-infected bacterial cells were uncommon in the pelagic habitat and undetectable in the benthos. Both lytic and lysogenic pelagic viral production rates were undetectable or low; thus, a possible explanation for the relative high viral abundances found in the water column could be an allochthonous input of viruses or release of sediment-derived viruses.

Overall, our results provide novel information about the relevance of viruses in the subarctic region and indicate that viruses play only a minor role in the nutrient and carbon cycling in the microbial communities of subarctic lakes.

Water -resources data, including stage and discharge data at most streamflow-gaging stations, are available throught the World Wide Web on the Internet. The Wisconsin District's home page is at http: Information on the Wisconsin District's Lakes Program is found at wi. Water -quality and lake stage data for Wisconsin lakes , water year Information on the Wisconsin District's Lakes Program is found atwi. Viruses and bacteria in floodplain lakes along a major Amazon tributary respond to distance to the Amazon River.

In response to the massive volume of water along the Amazon River, the Amazon tributaries have their water backed up by s of kilometers upstream their mouth. This backwater effect is part of the complex hydrodynamics of Amazonian surface waters , which in turn drives the variation in concentrations of organic matter and nutrients, and also regulates planktonic communities such as viruses and bacteria. Viruses and bacteria are commonly tightly coupled to each other, and their ecological role in aquatic food webs has been increasingly recognized.

Here, we surveyed viral and bacterial abundances BAs in 26 floodplain lakes along the Trombetas River, the largest clear- water tributary of the Amazon River's north margin. We correlated viral and BAs with temperature, pH, dissolved inorganic carbon, dissolved organic carbon DOC , phosphorus, nitrogen, turbidity, water transparency, partial pressure of carbon dioxide pCO2 , phytoplankton abundance, and distance from the lake mouth until the confluence of the Trombetas with the Amazon River.

We hypothesized that both bacterial and viral abundances VAs would change along a latitudinal gradient, as the backwater effect becomes more intense with increased proximity to the Amazon River; different flood duration and intensity among lakes and waters with contrasting sources would cause spatial variation.

Our measurements were performed during the low water period, when floodplain lakes are in their most lake -like conditions. Most viruses were bacteriophages, as viruses were strongly linked to bacteria , but not to phytoplankton. Our results highlight that hydrodynamics plays a key role in the regulation of planktonic viral and bacterial communities in Amazonian floodplain lakes.

The percentage of [methyl-3H]thymidine incorporated into samples from a dimictic eutrophic lake and retained on polycarbonate membranes of 3. Water samples were also examined by epifluorescence microscopy for evidence of algal senescence and bacterial colonization of intact and damaged cyanobacterial filaments.

Epilimnetic samples also had a small percentage of cyanobacterial filaments, either intact or damaged, which were visibly colonized by bacteria in summer and fall samples. The proportion of damaged cyanobacterial filaments was higher in these samples than in those from the epilimnion or from those obtained early in the summer. Furthermore, the filaments in these samples were more heavily colonized by bacteria.

It appears that the supply of colonizable particles damaged cyanobacterial filaments is an important factor affecting the level of particle-bound bacterial activity in this lake. Factors controlling bacteria and protists in selected Mazurian eutrophic lakes North-Eastern Poland during spring.

Background The bottom-up food resources and top-down grazing pressure controls, with other environmental parameters water temperature, pH are the main factors regulating the abundance and structure of microbial communities in aquatic ecosystems.

It is still not definitively decided which of the two control mechanisms is more important. The significance of bottom-up versus top-down controls may alter with lake productivity and season. The studied lakes were characterized by high nanoflagellate mean Among the staining methods used to examine bacterial cellular metabolic activity, the lowest percentage of active cells was recorded with the CTC 1.

Conclusions In the euphotic zone, the bottom-up factors TP and DOC concentrations played a more important role than top-down control grazing by protists in regulating bacterial numbers and activity. Geological Survey USGS , in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes.

To make these data available to interested parties outside the USGS, the data are published annually in this report series. The locations of water -quality and lake -stage stations in Wisconsin for water year are shown in figure 1. A water year is the month period from October 1 through September It is designated by the calendar year in which it ends. Thus, the period October 1, through September 30, is called ' water year Data collected include measurements of in- lake water quality and lake stage.

Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Vertical distribution of Archaea and Bacteria in a meromictic lake as determined by fluorescent in situ hybridization. The prokaryotic cells distribution in the water column of the coastal saline meromictic Lake Faro Messina, Italy was investigated by microscopic counting techniques.

Water samples were collected at a central station from the surface to the bottom, when waters were characterized by a marked stratification. A "red- water " layer, caused by a dense growth of photosynthetic sulfur bacteria , was present at a depth of 15 m, defining a transition area between oxic mixolimnion and anoxic monimolimnion layers.

Bacteria decreased from surface to bottom, while Archaea increased with depth and reached the maximum value at 30 m, where they outnumbered the Bacteria. Bacteria and picophytoplankton prevailed in the mixolimnion. At the chemocline high numbers of prokaryotic cells were present, mainly represented by Cyanobacteria, Chromatium okenii and Euryarchaeota. Although Archaea constitute a minor fraction of microbial community, they could represent active contributors to the meromictic Lake Faro ecosystem.

Effects of residential development on the water quality of Higgins Lake , Michigan Higgins Lake , a popular recreation area in the north-central Lower Peninsula of Michigan, drains an area of 58 square miles and is composed of two deep basins separated by a narrow channel between Flag Point and Point Detroit.

The North and South Basins have a maximum depth of about and feet respectively. The quality of the lake water near shore has been affected by residential development.

The concentration of chloride and turbidity in the lake water near the shore increases with increases in building and road density. Nitrogen concentration in lake water near shore also has increased the most in areas where buildings exceed a density of 0. Ground water beneath the lake showed higher concentrations of phosphorus, nitrogen, chloride, and boron than the lake-water samples.

Phosphorus concentration in lake and ground water appears to be more affected by site-specific conditions, such as soil type and distance of sampling sites from individual septic systems, than by building density alone.

Energy and water in the Great Lakes. The nexus between thermoelectric power production and water use is not uniform across the U. That is, in some regions water demand for thermoelectric production is relatively small while in other regions it represents the dominate use. The later is the case for the Great Lakes region, which has important implications for the water resources and aquatic ecology of the Great Lakes watershed.

This is today, but what about the future? Projected demographic trends, shifting lifestyles, and economic growth coupled with the threat of global climate change and mounting pressure for greater U. Planning for such an uncertain future is further complicated by the fact that energy and environmental planning and regulatory decisionmaking is largely bifurcated in the region, with environmental and water resource concerns generally taken into account after new energy facilities and technologies have been proposed, or practices are already in place.

Based on these confounding needs, the objective of this effort is to develop Great Lakes -specific methods and tools to integrate energy and water resource planning and thereby support the dual goals of smarter energy planning and development, and protection of Great Lakes water resources. Guiding policies for this planning are the Great Lakes and St. The desired outcome of integrated energy- water -aquatic resource planning is a more sustainable regional energy mix for the Great Lakes basin ecosystem.

Great Lakes Energy- Water Model. Planning for such an uncertain future is further complicated by the fact that energy and environmental planning and regulatory decision-making is largely bifurcated in the region, with environmental and water resource concerns generally taken into account after new energy facilities and technologies have been proposed, or practices are already in place. The location of water -quality and lake -stage stations in Wisconsin for water year are shown in figure 1.

Thus, the period October 1, through September 30, is called ' water year '. Data collected include measurements of lake stage and in- lake water quality. Graphs of Secchi depths, surface total-phosphorus and chlorophyll-a concentrations versus time are usually included for lakes with two or more years of data.

Viability and potential for immigration of airborne bacteria from Africa that reach high mountain lakes in Europe. We have analysed the diversity of the bacteria , which grow after addition of concentrated airborne particles and desert dust in different microcosms combinations with water samples from oligotrophic alpine lakes. We used, on the one hand, airborne bacteria transported by an African dust plume and collected in a high mountain area in the central Pyrenees Spain.

On the other hand, we collected desert dust in Mauritania c. In all the dust-amended treatments we consistently observed bacterial growth of common phyla usually found in freshwater ecosystems, i.

Alpha-, Beta- and Gammaproteobacteria, Actinobacteria, and a few Bacteroidetes, but with different composition based on lake water pretreatment and dust type. Overall, we tentatively split the bacterial community in i typical freshwater non-airborne bacteria , ii cosmopolitan long-distance airborne bacteria , iii non-freshwater low-distance airborne bacteria , iv non-freshwater long-distance airborne soil bacteria and v freshwater non-soil airborne bacteria.

We identified viable long-distance airborne bacteria as immigrants in alpine lakes e. Sphingomonas-like but also viable putative airborne pathogens with the potential to grow in remote alpine areas Acinetobacter-like and Arthrobacter-like. Generation of atmospheric aerosols and remote dust deposition is a global process, largely enhanced by perturbations linked to the global change, and high mountain lakes are very convenient worldwide model systems for monitoring global-scale bacterial dispersion and pathogens entries in remote pristine environments.

Survival of lake trout eggs and fry reared in water from the upper Great Lakes. As part of continuing studies of the reproductive failure of lake trout Salvelinus namaycush in Lake Michigan, we measured the survival of lake trout eggs and fry of different origins and reared in different environments. Eggs and milt were stripped from spawning lake trout collected in the fall of from southeastern Lake Michigan, northwestern Lake Huron, south central Lake Superior, and from hatchery brood stock.

Eggs from all sources were incubated, and the newly hatched fry were reared for days in lake water from each of the three upper Great Lakes and in well water. Comparisons of incubation water from the different lakes indicated that hatching success of eggs from all sources was highest in Lake Huron water , and lowest in Lake Michigan water.

The most notable finding was the nearly total mortality of fry from eggs of southeastern Lake Michigan lake trout. In a comparison of the rearing sites, little influence of water quality on fry survival was found.

Thus, the poor survival was associated with the source of eggs and sperm, not the water in which the fry were reared. Coliform bacteria isolated from recreational lakes carry class 1 and class 2 integrons and virulence-associated genes. To characterize the integron-harbouring Gram-negative bacteria in recreational lakes , with focus on the genetic content of integrons, antimicrobial resistance profiles and virulence-associated genes. Antimicrobial resistance testing was done by disc diffusion method.

Virulence-associated genes in integron-bearing Escherichia coli isolates were detected by PCR. A total of integron-bearing strains of coliform bacteria were cultured.

Higher frequency of integron-positive bacteria and higher antimicrobial resistance ranges were noted in colder months January and November compared with spring and summer months. Integron-bearing multidrug resistant coliform bacteria carrying virulence genes are present in waters of recreational lakes. This study presents antimicrobial resistance and virulence-associated genes in integron-bearing coliform bacteria present in the waters of recreational lakes , which showed that multidrug resistant bacteria with virulence traits might pose a threat to public health.

Moreover, the presence of genes typical for enterotoxigenic and Shiga toxin-producing E. Lakes and Reservoir Management, vol. Due to the rapidly rising production and usage of nano-enabled products, aquatic environments are increasingly exposed to engineered nanoparticles ENPs , causing concerns about their potential negative effects.

In this study we assessed the effects of uncoated titanium dioxide nanoparticles TiO2NPs on the growth and activity of bacterial communities of three Swedish lakes featuring different chemical characteristics such as dissolved organic carbon DOC concentration, pH and elemental composition.

The nanoparticles were most stable in lake water with high DOC and low chemical element concentrations. The cell-specific bacterial activity was significantly enhanced at high TiO2NP exposure concentrations, indicating the loss of nanoparticle-sensitive bacteria and a subsequent increased activity by tolerant ones.

We conclude that in freshwater lakes with high DOC and low chemical element concentrations, uncoated TiO2NPs show an enhanced stability and can significantly reduce bacterial abundance at relatively low exposure concentrations. The Wisconsin Water Science Center's home page is at http: The effects of using ground water to maintain water levels of Cedar Lake , Wisconsin. There were no identifiable changes in measured physical and chemical characteristics of lake water during sustained pumping of ground water into the lake , nor were there identifiable changes in the number or makeup of the phytoplankton community.

Differences in physical and chemical characteristics of lake water and ground water added to the lake probably were not great enough to cause changes within the lake. Bacteria foraging in turbulent waters. Bacteria forage on patches of dissolved nutrients using chemotaxis, the ability to swim up chemical gradients. As turbulence is ubiquitous in the Ocean, it is important to understand how turbulent flow conditions affect bacterial foraging.

We used three-dimensional, isotropic direct numerical simulations coupled with a bacterial transport equation to address this problem. After the flow is continuously forced until it reaches a steady state, microscale nutrient patches are injected into the turbulent flow, and stirring produces thin nutrient filaments.

Two populations of bacteria compete against each other: The distribution of both populations is initially uniform. Chemotaxis allows active bacteria to cluster near the center of the nutrient filaments, increasing their nutrient uptake relative to passive bacteria.

Increasing the turbulence intensity increases the short-term chemotactic advantage by quickly producing large gradients in the nutrient concentration, but also leads to rapid mixing of the nutrient field, which makes the chemotactic advantage short-lived. The results suggest that the evolutionary advantage of chemotaxis, based on the increase in nutrient uptake relative to the energetic cost of swimming, strongly depends on the turbulence level.

Water -quality and lake -stage data for Wisconsin Lakes , water year Anaerobic ammonium-oxidizing anammox process can play an important role in freshwater nitrogen cycle. However, the distribution of anammox bacteria in freshwater lake and the associated environmental factors remain essentially unclear.

The present study investigated the temporal and spatial dynamics of sediment anammox bacterial populations in eutrotrophic Dianchi Lake and mesotrophic Erhai Lake on the Yunnan Plateau southwestern China.

The remarkable spatial change of anammox bacterial abundance was found in Dianchi Lake , while the relatively slight spatial shift occurred in Erhai Lake. Dianchi Lake had greater anammox bacterial abundance than Erhai Lake. In both Dianchi Lake and Erhai Lake , anammox bacteria were much more abundant in summer than in spring.

Anammox bacterial community richness, diversity, and structure in these two freshwater lakes were subjected to temporal and spatial variations. Sediment anammox bacterial communities in Dianchi Lake and Erhai Lake were dominated by Candidatus Brocadia and a novel phylotype followed by Candidatus Kuenenia; however, these two lakes had distinct anammox bacterial community structure.

In addition, trophic status determined sediment anammox bacterial community structure. The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes during water years — Thus, the period October 1, through September 30, is called " water year Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes , are available via the "USGS Annual Water Data Report" Web site: Our planet's surface waters are a fundamental resource encompassing a broad range of ecosystems that are core to global biogeochemical cycling, biodiversity and food and energy security.

Despite this, these same waters are impacted by multiple natural and anthropogenic pressures and drivers of environmental change. The complex interaction between physical, chemical and biological processes in surface waters poses significant challenges for in situ monitoring and assessment and this often limits our ability to adequately capture the dynamics of aquatic systems and our understanding of their status, functioning and response to pressures.

Recent developments in the availability of satellite platforms for Earth observation including ESA's Copernicus Programme offers an unprecedented opportunity to deliver measures of water quality at a global scale. The UK NERC-funded Globo Lakes project is a five-year research programme investigating the state of lakes and their response to climatic and other environmental drivers of change through the realization of a near-real time satellite based observatory Sentinel-3 and archive data processing MERIS, SeaWiFS to produce a year time-series of observed ecological parameters and lake temperature for more than lakes globally.

However, the diverse and complex optical properties of lakes mean that algorithm performance often varies markedly between different water types. The Globo Lakes project is overcoming this challenge by developing a processing chain whereby algorithms are dynamically selected according to the optical properties of the lake under observation. The development and validation of the Globo Lakes processing chain has been supported by access to extensive in situ data from more than thirty partners around the world that are now held in the LIMNADES community-owned data repository developed under the auspices of Globo Lakes.

This approach has resulted in a step-change in our ability to produce regional and. Microbial water quality in freshwater lakes with different land use. The relationship between land use undeveloped, cattle grazing, urban , faecal indicator bacteria FIB levels and microbial source tracking MST marker detection was investigated in lakes created following phosphate mining.

FIB levels varied significantly by sampling date and were correlated with antecedent rainfall. FIB levels varied with land use category only in the case of faecal coliform levels in sediments of urban lakes , which were significantly greater than those in undeveloped or cattle-impacted lakes. HPyVs was the only human source marker detected.

Rainfall was more strongly associated with FIB levels than land use category. The detection frequency of only the ruminant MST marker was associated with land use. Microbial source tracking MST can fine-tune the assessment of human health risk from recreational use of inland waters , particularly when similar FIB levels but different surrounding land use and probable impacts exist.

Denitrifying and anammox bacteria are involved in the nitrogen cycling in marine sediments but the environmental factors that regulate the relative importance of these processes are not well constrained. Here, we evaluated the abundance, diversity, and potential activity of denitrifying, anammox, and sulfide-dependent denitrifying bacteria in the sediments of the seasonally hypoxic saline Lake Grevelingen, known to harbor an active microbial community involved in sulfur oxidation pathways.

Depth distributions of 16S rRNA gene, nirS gene of denitrifying and anammox bacteria , aprA gene of sulfur-oxidizing and sulfate-reducing bacteria , and ladderane lipids of anammox bacteria were studied in sediments impacted by seasonally hypoxic bottom waters.

Samples were collected down to 5 cm depth 1 cm resolution at three different locations before March and during summer hypoxia August. The abundance of denitrifying bacteria did not vary despite of differences in oxygen and sulfide availability in the sediments, whereas anammox bacteria were more abundant in the summer hypoxia but in those sediments with lower sulfide concentrations.

The simultaneous presence and activity of organoheterotrophic denitrifying bacteria , sulfide-dependent denitrifiers, and anammox bacteria suggests a tight network of bacteria coupling carbon-, nitrogen-, and sulfur cycling in Lake Grevelingen sediments. Water -quality and lake -stage data for Wisconsin lakes , water years — Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes , are published online at http: Water -resources data, including stage and discharge data at most streamflow-gaging stations, are available online.

These data, accumulated over many years, provide a database for developing an improved understanding of the water quality of lakes.

Time series of Secchi depths, surface total phosphorus, and chlorophyll a concentrations collected during nonfrozen periods are included for many lakes. The purpose of this report is to provide information about the chemical and physical charac-teristics of Wisconsin lakes.

Data collected include measure-ments of in- lake water quality and lake stage. Time series graphs of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Descriptive infor-mation for each lake includes: Ecological dynamics of toxic Microcystis spp.

Toxic cyanobacterial blooms directly threaten both human safety and the ecosystem of surface waters. The widespread occurrence of these organisms, coupled with the tumor-promoting properties of the microcystin toxins that they produce, demands action to mitigate their potential impacts and, thus, a robust understanding of their ecological dynamics. In the present work, the abundance of toxic Microcystis spp.

Samples were taken at monthly intervals from June to December at three sampling stations within this freshwater lake. Results revealed that variation in the abundance of both total Microcystis spp. Importantly, we observed that peaks in mlrA gene copy numbers of MC-degrading bacteria occurred in the months following observed peaks in MC concentrations. To understand this phenomenon, we added MCs to the MC-degrading bacteria designated strains HW and SW in this study and found that MCs significantly enhanced mlrA gene copy numbers over the number for the control by a factor of 5.

These results indicate that toxic Microcystis and MC-degrading bacteria exert both direct and indirect effects on each other and that MC-degrading bacteria also mediate a shift from toxic to nontoxic populations of Microcystis. The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes. Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are usually included for lakes with two or more years of data.

Vertical stratification of bacteria and archaea in sediments of a boreal stratified humic lake. Boreal stratified humic lakes , with steep redox gradients in the water column and in the sediment, are important sources of methane CH4 to the atmosphere.

CH4 flux from these lakes is largely controlled by the balance between CH4-production methanogenesis , which takes place in the organic rich sediment and in the deepest water layers, and CH4-consumption methanotrophy , which takes place mainly in the water column.

While there is already some published information on the activity, diversity and community structure of bacteria in the water columns of these lakes , such information on sediment microbial communities is very scarce. This study aims to characterize the vertical variation patterns in the diversity and the structure of microbial communities in sediment of a boreal stratified lake. Particular focus is on microbes with the potential to contribute to methanogenesis fermentative bacteria and methanogenic archaea and to methanotrophy methanotrophic bacteria and archaea.

The abundance of methanogenic archaea was also specifically studied by quantitative-PCR of methyl coenzyme-M reductase gene mcrA amplicons. Furthermore, the community structure and the abundance of bacteria were studied by phospholipid fatty acid PLFA analysis. Dominant potential fermentative bacteria belonged to families Syntrophaceae, Clostridiaceae and Peptostreptococcaceae.

There were considerable differences in the vertical distribution among these groups. The relative abundance of Syntrophaceae started to increase from the sediment surface, peaked at depth layer from 5 to 10 cm up. Abundance and diversity of ammonia-oxidizing bacteria in relation to ammonium in a chinese shallow eutrophic urban lake. The measures of most-probable-number and restriction fragment length polymorphism analysis were used to analyze the abundance and diversity of ammonia-oxidizing bacteria in sediment of a Chinese shallow eutrophic urban lake Lake Yuehu.

Among the 5 sampling sites, ammonia concentration in interstitial water was positively proportional not only to the content of organic matter, but also to ammonia-oxidizing bacteria numbers at a magnitude of cells g-1 dry weight in sediment significantly.

Furthermore, the diversity of ammonia-oxidizing bacteria were determined by means of PCR primers targeting the amoA gene with five gene libraries created and restriction pattern analysis. The 13 restriction patterns were recorded with 4 ones being common among all sampling sites. Thus, the abundance and diversity of sediment AOB is closely linked to ammonium status in eutrophic lakes.

According to the results of seasonal monitoring, in purple sulfur bacteria morphologically similar to Thiocapsa sp. No pronounced seasonal periodicity in the total cell number in the water column was revealed during the period of observation. In some years cell number during the period when the lake was covered with ice was reliably higher than in summer.

The absence ofseasonal periodicity was probably due to the low amplitude of seasonal variations in temperature and illumination in the redox zone, resulting from its relatively deep location m. The year-to-year dynamics was characterized by a reliable decrease of the total cell number in and maxima in and Canonical correlation analysis revealed that water temperature in the redox zone was the best predictor of the PSB abundance in Lake Shira.

Water temperature, in turn, depended on the depth of mixing of the water column. Intense mixing in was probably responsible for decreased PSB abundance in the lake. On the other hand, the absence of deep winter mixing, resulting in stable conditions in the chemocline, favored the preservation of relatively high PSB biomass. Prediction of circulation depth, which. These results may be useful for paleolimnological reconstructions of the history of the lake based on the remnants of purple sulfur bacteria in bottom sediments.

The water levels of Lake Saumatre in Haiti and Lake Enriquillo in the Dominican Republic have been increasing continuously for the past years. As result roads and lake shore agriculture are flooded and there is an interest in determining the causes of the continuous lake growth and finding solutions to reverse the trend Various theories haven proposed for growth of the lakes such as climate change and deforestation.

Deforestation would affect the hydrological balance by means of changing infiltration rates. To examine the temporal variations in the lake , the lake surface areas during the past 30 years were obtained from available satellite data and converted into volumes.

These lake surface areas showed a steady increase starting in for Lake Saumatre and in for Lake Enriquillo. Land cover change obtained by means of remote sensing for the years of and showed no significant change and could therefore be ruled out as a cause for the lake levels increases.

A simple water balance model that had been validated for monsoon climates matched the lake level volumes fluctuations well for the last 30 years including the recent rise in lake levels. Thus the lake level increases could be directly related to the greater precipitation starting some 10 years ago. The difference in starting time of lake level rise between the two lakes could be explained by a larger storage capacity in the a Lake Enriquillo watershed compared to the Lake Saumatre watershed.

Contamination of water resources by pathogenic bacteria. Water -borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water -borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole.

Providing a broader perceptive of pathogen contamination in freshwater rivers, lakes , reservoirs, groundwater and saline water estuaries and coastal waters resources, this review paper attempts to develop the first comprehensive single source of existing information on pathogen contamination in multiple types of water resources. In addition, a comprehensive discussion describes the challenges associated with using indicator organisms.

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Among the proteins uniquely found in xylem plasma membranes were most of the enzymes involved in lignin biosynthesis, which suggests that they may exist as a complex linked to the plasma membrane. A laser microsurgical method of cell wall removal allows detection of large-conductance ion channels in the guard cell plasma membrane.

Application of patch clamp techniques to higher-plant cells has been subject to the limitation that the requisite contact of the patch electrode with the cell membrane necessitates prior enzymatic removal of the plant cell wall.

Because the wall is an integral component of plant cells , and because cell-wall -degrading enzymes can disrupt membrane properties, such enzymatic treatments may alter ion channel behavior.

We compared ion channel activity in enzymatically isolated protoplasts of Vicia faba guard cells with that found in membranes exposed by a laser microsurgical technique in which only a tiny portion of the cell wall is removed while the rest of the cell remains intact within its tissue environment. These data indicate that ion channels are present in plant membranes that are not detected by conventional patch clamp techniques involving the production of individual plant protoplasts isolated from their tissue environment by enzymatic digestion of the cell wall.

Given the large conductances of the channels revealed by laser-assisted patch clamping, we hypothesize that these channels play a significant role in the regulation of ion content and electrical signalling in guard cells. Interactions between plant cell walls and plasma membranes are essential for cells to function properly, but the molecules that mediate the structural continuity between wall and membrane are unknown.

Some of these interactions, which are visualized upon tissue plasmolysis in Arabidopsis Arabidopsis thaliana , are disrupted by the RGD arginine-glycine-aspartic acid tripeptide sequence, a characteristic cell adhesion motif in mammals. To identify peptide sequences that specifically bind the RGD motif of the IPI-O protein and potentially play a role in receptor recognition, we screened a heptamer peptide library displayed in a filamentous phage and selected two peptides acting as inhibitors of the plasma membrane RGD-binding activity of Arabidopsis.

Moreover, the two peptides also disrupted cell wall -plasma membrane adhesions. Sequence comparison of the RGD-binding peptides with the Arabidopsis proteome revealed 12 proteins containing amino acid sequences in their extracellular domains common with the two RGD-binding peptides. Eight belong to the receptor-like kinase family, four of which have a lectin-like extracellular domain.

The lectin domain of one of these, At5g, recognized the RGD motif both in peptides and proteins. These results imply that lectin receptor kinases are involved in protein-protein interactions with RGD-containing proteins as potential ligands, and play a structural and signaling role at the plant cell surfaces.

Lectin receptor kinases participate in protein-protein interactions to mediate plasma membrane-cell wall adhesions in Arabidopsis. High affinity RGD-binding sites at the plasma membrane of Arabidopsis thaliana links the cell wall.

The heptapeptide Tyr-Gly-Arg-Gly-Asp-Ser-Pro containing the sequence Arg-Gly-Asp RGD--the essential structure recognised by animal cells in substrate adhesion molecules was tested on epidermal cells of onion and cultured cells of Arabidopsis upon plasmolysis. Dramatic changes were observed on both types of cells following treatment: Protoplasts isolated from Arabidopsis cells agglutinate in the presence of ProNectinF, a genetically engineered protein of 72 kDa containing 13 RGD sequences: The addition of the RGD-heptapeptide disrupted the adhesion between the protoplasts.

Purified plasma membrane from Arabidopsis cells exhibits specific binding sites for the iodinated RGD-heptapeptide. The binding is saturable, reversible, and two types of high affinity sites Kd1 approximately 1 nM, and Kd2 approximately 40 nM can be discerned.

Competitive inhibition by several structurally related peptides and proteins noted the specific requirement for the RGD sequence. Thus, the RGD-binding activity of Arabidopsis fulfils the adhesion features of integrins, i. Cell wall accumulation of fluorescent proteins derived from a trans-Golgi cisternal membrane marker and paramural bodies in interdigitated Arabidopsis leaf epidermal cells.

In most dicotyledonous plants, leaf epidermal pavement cells develop jigsaw puzzle-like shapes during cell expansion. Therefore, visualization of membrane trafficking in leaf pavement cells should contribute an understanding of the mechanism of plant cell morphogenesis. To reveal membrane trafficking in pavement cells , we observed monomeric red fluorescent protein-tagged rat sialyl transferases, which are markers of trans-Golgi cisternal membranes , in the leaf epidermis of Arabidopsis thaliana.

Quantitative fluorescence imaging techniques and immunoelectron microscopic observations revealed that accumulation of the red fluorescent protein occurred mostly in the curved regions of pavement cell borders and guard cell ends during leaf expansion. Transmission electron microscopy observations revealed that apoplastic vesicular membrane structures called paramural bodies were more frequent beneath the curved cell wall regions of interdigitated pavement cells and guard cell ends in young leaf epidermis.

In addition, pharmacological studies showed that perturbations in membrane trafficking resulted in simple cell shapes. These results suggested possible heterogeneity of the curved regions of plasma membranes , implying a relationship with pavement cell morphogenesis. An enzyme complex responsible for the TUA chain biosynthesis was purified and characterized.

TUAS displays hydrophobic properties and is found primarily associated with the cytoplasmic membrane. The purified TUAS contains carotinoids and lipids. TUAS activity is diminished by phospholipase digestion. We propose that TUAS serves as a multitasking polysaccharide assembling station on the bacterial membrane. Actin filaments regulate the adhesion between the plasma membrane and the cell wall of tobacco guard cells.

During the opening and closing of stomata, guard cells undergo rapid and reversible changes in their volume and shape, which affects the adhesion of the plasma membrane PM to the cell wall CW. The dynamics of actin filaments in guard cells are involved in stomatal movement by regulating structural changes and intracellular signaling.

However, it is unclear whether actin dynamics regulate the adhesion of the PM to the CW. In this study, we investigated the relationship between actin dynamics and PM-CW adhesion by the hyperosmotic-induced plasmolysis of tobacco guard cells. We found that actin filaments in guard cells were depolymerized during mannitol-induced plasmolysis. However, treatment with latrunculin B alleviated the RGDS peptide-induced plasmolysis and endocytosis.

Our results reveal that the actin depolymerization is involved in the regulation of the PW-CW adhesion during hyperosmotic-induced plasmolysis in tobacco guard cells. In this study, a series of nanocomposite membranes were fabricated with the PVA-influenced functionalized MWCNTs reinforced into the Nafion polymer matrix by a solution casting method.

After that, the nanocomposite membranes were characterized by thermo-gravimetric analysis TGA to observe the thermal enhancement caused by effective cross-linking between the f-MWCNTs with the composite polymer matrixes. Diffusion of nitric oxide across cell membranes of the vascular wall requires specific connexin-based channels. NO is generated within cells and frequently must be transferred to responsive neighboring cells , as occurs in the endothelium-dependent relaxation of smooth muscle cells observed in blood vessels.

It is thought that NO diffuses freely across cell membranes , but it may also permeate through low resistant membrane pathways. Here, we describe the participation of connexin Cx -formed channels in the NO transport across cell membranes and between endothelial and smooth muscle cells. We used a water-soluble NO donor of high molecular weight S-nitrosylated albumin, BSA-NO that does not permeate through cell membranes or Cx-based channels and the NO-sensitive dye 4,5-diaminofluorescein diacetate to detect changes of intracellular NO concentration.

We found that NO generated in the extracellular space was not detected intracellularly in Cx-deficient HeLa cells , suggesting that cell membrane represents a significant diffusion barrier for NO transfer. In contrast, NO closed hemichannels of HeLa-Cx32 cells , which otherwise are permeable to NO if are opened by a divalent cation-free extracellular solution. Consistent with this, blockade of Cx-based channels abolished the myoendothelial NO transfer and associated NO-dependent vasodilation induced by acethylcholine.

These results indicate that Cx-based channels play a key role in the NO-dependent tonic control of vascular function and may direct the NO signal to specific targets, which provides a novel mechanistic basis for the critical role of Cxs in cell-cell communication in the vessel wall. Perturbation of the Staphylococcus aureus cytoplasmic membrane CM is felt to play a key role in the microbicidal mechanism of many antimicrobial peptides APs.

We hypothesized that the relationships between MP and killing may differ for distinct APs. Four APs with different structure-activity relationships were examined: MP was quantified fluorometrically by calcein release.

All APs tested, except polymyxin B, caused concentration-dependent MP and killing of whole cells , but not of protoplasts. The reduced AP susceptibility of protoplasts was associated with increased cardiolipin and lysyl-phosphatidylglycerol content and reduced fluidity of their CMs.

Collectively, these results indicate that i structurally distinct APs likely exert their staphylocidal effects by differing mechanisms, ii MP is not the sole event leading to AP-induced staphylocidal activity, iii a complex interrelationship exists between the CM and CW in AP-induced killing, and iv liposomes modeled upon whole cell or protoplast CMs can recapitulate the respective susceptibilities to killing by distinct APs.

Peptidoglycan is the major component of the cell envelope of virtually all bacteria. It has structural roles and acts as a selective sieve for molecules from the outer environment. Peptidoglycan synthesis is therefore one of the most important biogenesis pathways in bacteria and has been studied extensively over the last twenty years.

The pathway starts in the cytoplasm, continues in the cytoplasmic membrane and finishes in the periplasmic space, where the precursor is polymerized into the peptidoglycan layer. A number of proteins involved in this pathway, such as the Mur enzymes and the penicillin binding proteins PBPs , have been studied and regarded as good targets for antibiotics. The present review focuses on the membrane steps of peptidoglycan synthesis that involve two enzymes, MraY and MurG, the inhibitors of these enzymes and the inhibition mechanisms.

We also discuss the challenges of targeting these two cytoplasmic membrane associated proteins in bacterial cells and the perspectives on how to overcome the issues. Knockout of the alanine racemase gene in Aeromonas hydrophila HBNUAh01 results in cell wall damage and enhanced membrane permeability.

This study focused on the alanine racemase gene alr-2 , which is involved in the synthesis of d-alanine that forms the backbone of the cell wall. When the mutant was supplemented with d-alanine, growth was unaffected; deprivation of d-alanine caused the growth arrest of the starved mutant cells , but not cell lysis. No alanine racemase activity was detected in the culture of the mutant.

Additionally, a membrane permeability assay showed increasing damage to the cell wall during d-alanine starvation. No such damage was observed in the wild type during culture.

Scanning and transmission electron microscopy analyses revealed deficiencies of the cell envelope and perforation of the cell wall. Leakage of UV-absorbing substances from the mutants was also observed. Thus, the partial viability of the mutants and their independence of d-alanine for growth indicated that inactivation of alr-2 does not impose an auxotrophic requirement for d-alanine.

Effect of chirality and length on the penetrability of single- walled carbon nanotubes into lipid bilayer cell membranes. The ability of carbon nanotubes to enter the cell membrane acting as drug-delivery vehicles has yielded a plethora of experimental investigations, mostly with inconclusive results because of the wide spectra of carbon nanotube structures. Because of the virtual impossibility of synthesizing CNTs with distinct chirality, we report a parametric study on the use of molecular dynamics to provide better insight into the effect of the carbon nanotube chirality and the aspect ratio on the interaction with a lipid bilayer membrane.

The simulation results indicated that a single- walled carbon nanotube utilizes different time-evolving mechanisms to facilitate their internalization within the membrane.

These mechanisms comprise both penetration and endocytosis. It was observed that carbon nanotubes with higher aspect ratios penetrate the membrane faster whereas shorter nanotubes undergo significant rotation during the final stages of endocytosis.

Furthermore, nanotubes with lower chiral indices developed significant adhesion with the membrane. This adhesion is hypothesized to consume some of the carbon nanotube energy, thus resulting in longer times for the nanotube to translocate through the membrane.

Combined effect of synthetic enterocin CRL35 with cell wall , membrane -acting antibiotics and muranolytic enzymes against Listeria cells. To evaluate the inhibition effectiveness of enterocin CRL35 in combination with cell wall , membrane -acting antibiotics and muranolytic enzymes against the foodborne pathogen Listeria. Synthetic enterocin CRL35 alone and in combination with monensin, bacitracin, gramicidin, mutanolysin and lysozyme were used in this study.

Antibiotics showed positive interactions with the bacteriocin in both strains tested. On the other hand, when mutanolysin and enterocin CRL35 were added to resting cells in a buffer system, the lytic effect of mutanolysin was enhanced. However, the addition of mutanolysin showed no effect on the growth of L. Moreover, mutanolysin allowed the overgrowth of L. Based on our results, we conclude that the combination of synthetic enterocin CRL35 with some antibiotics is effective against L.

The effectiveness of the combination of synthetic enterocin CRL35 with muramidases seems to depend on complex environments, and more detailed studies need to be performed to elucidate this issue.

Enterocin CRL35 represents a promising agent that not only can ensure the quality and safety of food but it can also be combined with several antimicrobial agents important in the medical field.

Deciphering the Metabolism of Undecaprenyl-Phosphate: During the biogenesis of bacterial cell-wall polysaccharides, such as peptidoglycan, cytoplasmic synthesized precursors should be trafficked across the plasma membrane. This essential process requires a dedicated lipid, undecaprenyl-phosphate that is used as a glycan lipid carrier.

The sugar is linked to the lipid carrier at the inner face of the membrane and is translocated toward the periplasm, where the glycan moiety is transferred to the growing polymer. Undecaprenyl-phosphate originates from the dephosphorylation of its precursor undecaprenyl-diphosphate, with itself generated by de novo synthesis or by recycling after the final glycan transfer.

Undecaprenyl-diphosphate is de novo synthesized by the cytosolic cis-prenyltransferase undecaprenyl-diphosphate synthase, which has been structurally and mechanistically characterized in great detail highlighting the condensation process. In contrast, the next step toward the formation of the lipid carrier, the dephosphorylation step, which has been overlooked for many years, has only started revealing surprising features.

In contrast to the previous step, two unrelated families of integral membrane proteins exhibit undecaprenyl-diphosphate phosphatase activity: BacA and members of the phosphatidic acid phosphatase type 2 super-family, raising the question of the significance of this multiplicity.

Moreover, these enzymes establish an unexpected link between the synthesis of bacterial cell-wall polymers and other biological processes.

In the present review, the current knowledge in the field of the bacterial lipid carrier, its mechanism of action, biogenesis, recycling, regulation, and future perspective works are presented.

Plants are able to generate large leaf surfaces that act as two-dimensional solar panels with a minimum investment in building material, thanks to a hydrostatic skeleton.

This requires high intracellular pressures up to 1 MPa , which depend on the presence of strong cell walls. The walls of growing cells also called primary walls , are remarkably able to reconcile extreme tensile strength up to MPa with the extensibility necessary for growth. All walled organisms are confronted with this dilemma - the need to balance strength and extensibility - and bacteria, fungi and plants have evolved independent solutions to cope.

In this Primer, we discuss how plant cells have solved this problem, allowing them to support often very large increases in volume and to develop a broad variety of shapes Figure 1A,B,D. This shape variation reflects the targeted deposition of wall material combined with local variations in cell-wall extensibility, processes that remain incompletely understood.

Once the cell has reached its final size, it can lay down secondary wall layers, the composition and architecture of which are optimized to exert specific functions in different cell types Figure 1E-G. Specialized secondary walls , such as those constituting seed mucilage, are stored in a dehydrated form in seedcoat epidermis cells and show rapid swelling upon hydration of the seed. Other walls , in particular in reserve tissues, can accommodate large amounts of storage polysaccharides, which can be easily mobilized as a carbon source.

Physiological and transcriptional responses of Saccharomyces cerevisiae to d-limonene show changes to the cell wall but not to the plasma membrane.

Monoterpenes can, upon hydrogenation, be used as light-fraction components of sustainable aviation fuels. Fermentative production of monoterpenes in engineered microorganisms, such as Saccharomyces cerevisiae, has gained attention as a potential route to deliver these next-generation fuels from renewable biomass.

However, end product toxicity presents a formidable problem for microbial synthesis. Due to their hydrophobicity, monoterpene inhibition has long been attributed to membrane interference, but the molecular mechanism remains largely unsolved.

We found no alterations in membrane fluidity, structural membrane integrity, or fatty acid composition after the solvent challenge. A 4-fold increase in the mean fluorescence intensity per cell using calcofluor white stain and increased sensitivity to cell wall -degrading enzymes demonstrated that limonene disrupts cell wall properties.

Global transcript measurements confirmed the membrane integrity observations by showing no upregulation of ergosterol or fatty acid biosynthesis pathways, which are commonly overexpressed in yeast to reinforce membrane rigidity during ethanol exposure.

This is the first report demonstrating that cell wall , rather than plasma membrane , deterioration is the main source of monoterpene inhibition. We show that limonene can alter the structure and function of the cell wall , which has a clear effect on cytokinesis. Proteins in the cell wall and membrane of Cryptococcus neoformans stimulate lymphocytes from both adults and fetal cord blood to proliferate.

Cryptococcus neoformans is an encapsulated yeast that infects patients who have defective cell -mediated immunity, including AIDS, but rarely infects individuals who have intact cell -mediated immunity. Studies of the immune response to C. The goal of this study was to separate C.

The lymphocyte response to fungal culture medium, whole organisms, disrupted organisms, and the yeast intracellular fraction or cell wall and membrane was studied by determining thymidine incorporation and by determining the number of lymphocytes at various times after stimulation. The cell wall and membrane of C. The optimal response occurred on day 7 of incubation, with 4 x 10 5 peripheral blood mononuclear cells per well and with 13 microg of cryptococcal protein per ml.

The number of lymphocytes increased with time in culture, indicating that thymidine incorporation was accompanied by proliferation. Proteinase K treatment of the cell wall and membrane abrogated lymphocyte proliferation, indicating that the molecule was a protein. At least 18 discrete bands were resolved from the cell wall and membrane. Since a large percentage of healthy adults responded to the cryptococcal cell wall and membrane , a mitogenic effect was investigated by testing proliferation of fetal cord blood.

An investigation into plasmolysis in the oomycete Achlya bisexualis reveals that membrane-wall attachment points are sensitive to peptides containing the sequence RGD and that cell wall deposition can occur despite retraction of the protoplast. The structure and function of membrane-wall attachment sites in walled cells , and how these relate to animal focal adhesions, is an area that is poorly understood.

In view of this, we investigated how membrane-wall attachments that form upon plasmolysis, respond to peptides that disrupt animal focal adhesions. The degree of cytoplasmic disruption during plasmolysis was also investigated. Upon hyperosmotic challenge, the protoplast in hyphae of the oomycete Achlya bisexualis typically retracted incompletely due to membrane-wall attachments.

The inclusion, in the plasmolysing solution, of peptides containing the sequence RGD disrupted these attachments in a dose-dependent manner. In some hyphae, protoplast retraction stopped temporarily at attachment points - upon resumption of retraction, material was left that traced the outline of the static protoplast. Staining of this material with fluorescence brightener indicated the presence of cellulose, which suggests that wall deposition was able to occur despite plasmolysis.

The F-actin cytoskeleton was disrupted during plasmolysis; peripheral F-actin staining was observed, but there was no distinct F-actin cap; staining was more diffuse; and there were fewer plaques compared with nonplasmolysed hyphae.

Our data indicate that membrane-wall attachment points are sensitive to RGD-containing peptides and that wall deposition continues despite protoplast retraction and F-actin disruption. Genome-wide reprogramming of regulatory networks, transport, cell wall and membrane biogenesis during arbuscular mycorrhizal symbiosis in Lotus japonicus.

As a consequence of the fungal colonization and of the deep reorganization shown by arbusculated cells , important impacts on root transcriptome are expected. Induction of a subset 24 genes of these was tested and confirmed by qRT-PCR, and transcript location in arbusculated cells was demonstrated for seven genes using laser-dissected cells.

Improving the electro-transformation efficiency of Corynebacterium glutamicum by weakening its cell wall and increasing the cytoplasmic membrane fluidity. To improve the transformation efficiency of Corynebacterium glutamicum cells with heterogenous plasmid DNA and single-strand DNA ssDNA using a methodology based on electro-transformation.

A semicomplex hypertonic medium was selected with addition of glycine and DL-threonine to weaken cell walls and addition of Tween 80 and isonicotinic acid hydrazide to increase cytoplasmic membrane fluidity. Their contents were optimized by response surface methodology. Cell growth, electro-transformation buffer, and transformation protocol were also optimized.

Temporary heating inactivation of the host restriction enzyme showed a significant effect. Finally, a high transformation efficiency of 3. The results shed light on the application in functional genomics and genome editing of C. The rice dynamin-related protein DRP2B mediates membrane trafficking, and thereby plays a critical role in secondary cell wall cellulose biosynthesis.

Membrane trafficking between the plasma membrane PM and intracellular compartments is an important process that regulates the deposition and metabolism of cell wall polysaccharides. Dynamin-related proteins DRPs , which function in membrane tubulation and vesiculation are closely associated with cell wall biogenesis.

However, the molecular mechanisms by which DRPs participate in cell wall formation are poorly understood. Consistent with the expression of BC3 in mechanical tissues, the bc3 mutation reduces mechanical strength, which results from decreased cellulose content and altered secondary wall structure.

Subcellular localization of fluorescence-tagged OsDRP2B and several compartment markers in protoplast cells showed that this protein not only lies at the PM and the clathrin-mediated vesicles, but also is targeted to the trans-Golgi network TGN. An FM uptake assay in transgenic plants that express green fluorescent protein-tagged OsDRP2B verified its involvement in an endocytic pathway. All of these findings lead us to conclude that OsDRP2B participates in the endocytic pathway, probably as well as in post-Golgi membrane trafficking.

Mutation of OsDRP2B disturbs the membrane trafficking that is essential for normal cellulose biosynthesis of the secondary cell wall , thereby leading to inferior mechanical properties in rice plants. Enzymatic biofuel cells EBFCs utilize enzymes to convert chemical energy present in renewable biofuels into electrical energy and have shown much promise in the continuous powering of implantable devices.

Currently, however, EBFCs are greatly limited in terms of power and operational stability with a majority of reported improvements requiring the inclusion of potentially toxic and unstable electron transfer mediators or multicompartment systems separated by a semipermeable membrane resulting in complicated setups. Glucose oxidase and bilirubin oxidase were physically adsorbed onto these electrodes to form anodes and cathodes, respectively, and the EBFC produced power densities up to 0.

Further, the electrodes were rejuvenated by a simple wash and reloading procedure. We postulate these porous and ultrahigh surface area electrodes will be useful for biosensing applications, and will allow reuse of EBFCs.

In this study the elastic spring constant of the yeast cell wall is probed with the atomic force microscope AFM under variable conditions. Cells were sequentially analyzed in rich growth medium YPD , a 0. Cells in late log phase, which have variable diameters within three to five microns, were immobilized on a patterned silicon substrate with holes approximately 3.

Force curves were taken moving laterally across the cell in one dimension after exposure to each medium. Spring constants of the cells , calculated from force curves, displayed a positional dependency and marked differences in high osmolarity medium and after the injection of sodium azide. This study demonstrates the ability of the AFM to investigate changes in cell morphology and correlate those findings to underlying physiological processes. The Lamportian cell wall.

The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks.

The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined.

Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: An electrochemical impedance spectroscopy study of polymer electrolyte membrane fuel cells electrocatalyst single wall carbon nanohorns-supported.

Additionally, as-prepared and oxidized SWNH Pt-supports were compared with conventional carbon black. Two different oxidizing treatments were considered: Both oxidizing treatments increased SWNH surface area; oxygen treatment increased surface area 4 times while acid treatment increased 2.

The increase in surface area should be related to the opening access to the inner tube of SWNH. On the other hand, the oxygen treated SWNH sample allowed to obtain the highest electrocatalyst load.

Moreover, EIS analysis indicated that the major improvement in performance is related to the cathode kinetics in the as-prepared SWNH sample, while concerning the oxidized SWNH sample, the improvements are related to the electrokinetics in both anode and cathode electrodes.

These improvements should be related with differences in the hydrophobic character between SWNH and carbon black. Lipoprotein cofactors located in the outer membrane activate bacterial cell wall polymerases. Most bacteria surround themselves with a peptidoglycan PG exoskeleton synthesized by polysaccharide polymerases called penicillin-binding proteins PBPs.

Because they are the targets of penicillin and related antibiotics, the structure and biochemical functions of the PBPs have been extensively studied. Overall, our results indicate that PBP accessory proteins play a central role in PG biogenesis, and like the PBPs they work with, these factors are attractive targets for antibiotic development.

Stabilization of glucose-C in microbial cell membranes PLFA and cell walls amino sugars evaluated by 13C-labelling in a field experiment. Microorganisms control carbon C cycle and strongly contribute to formation of soil organic matter. Strong differences in the turnover of microbial groups and cellular compounds complicate the assessment of their contribution to microbial food webs and C sequestration in soil in situ.

The uptake and incorporation of 13C labeled glucose by microbial groups were traced during 50 days after the labeling under field conditions. This allowed tracing C in microbial groups as well as cellular compounds. Such long cytosol MRT depends on its heterogeneous composition, which includes high and low molecular weight organics. Amino sugars were mainly originated from microbial residues and thus, observation periods higher than 1 year are required for estimation of their MRT.

Relative 13C incorporation into amino sugars of living microorganisms showed only 0. Therefore, the turnover of cell membrane components is two times faster than that of cell walls , even in living microorganisms.

Consequently, bacteria contribute more to the decomposition of low molecular weight organics, whereas fungi consume bacterial products or necromass and contribute more to long-term C stabilisation. Thus, tracing of 13C in cellular. Hydroxylation of multi- walled carbon nanotubes: Enhanced biocompatibility through reduction of oxidative stress initiated cell membrane damage, cell cycle arrestment and extrinsic apoptotic pathway. Modification of CNTs with hydroxyl group promotes their applications in biomedical area.

However, the impact of hydroxylation on their biocompatibility is far from being completely understood. More interestingly, MWCNTs-OH exhibited significantly lower tendency to activate caspase-8, a key molecule involved in the extrinsic apoptotic pathway. Arabidopsis NDR1 is an integrin-like protein with a role in fluid loss and plasma membrane-cell wall adhesion. Whereas the genetic requirement for NDR1 in plant disease resistance signaling has been detailed, our study focuses on determining a global, physiological role for NDR1.

Specific protein motifs also point to a degree of homology with mammalian integrins, well-characterized proteins involved in adhesion and signaling. This structural homology led us to examine a physiological role for NDR1 in preventing fluid loss and maintaining cell integrity through plasma membrane-cell wall adhesions.

Our results show a substantial alteration in induced i. As an extension of these analyses, using a combination of genetic and cell biology-based approaches, we have identified a role for NDR1 in mediating plasma membrane-cell wall adhesions. Taken together, our data point to a broad role for NDR1 both in mediating primary cellular functions in Arabidopsis through maintaining the integrity of the cell wall -plasma membrane connection and as a key signaling component of these responses during pathogen infection.

Fungal cell wall organization and biosynthesis. The composition and organization of the cell walls from Saccharomyces cerevisiae, Candida albicans, Aspergillus fumigatus, Schizosaccharomyces pombe, Neurospora crassa, and Cryptococcus neoformans are compared and contrasted.

A comparison of these cell walls shows that there is a great deal of variability in fungal cell wall composition and organization. However, in all cases, the cell wall components are cross-linked together to generate a cell wall matrix.

The biosynthesis and properties of each of the major cell wall components are discussed. The chitin and glucans are synthesized and extruded into the cell wall space by plasma membrane -associated chitin synthases and glucan synthases. The glycoproteins are synthesized by ER-associated ribosomes and pass through the canonical secretory pathway.

Over half of the major cell wall proteins are modified by the addition of a glycosylphosphatidylinositol anchor. The cell wall glycoproteins are also modified by the addition of O-linked oligosaccharides, and their N-linked oligosaccharides are extensively modified during their passage through the secretory pathway.

These cell wall glycoprotein posttranslational modifications are essential for cross-linking the proteins into the cell wall matrix. Cross-linking the cell wall components together is essential for cell wall integrity. The activities of four groups of cross-linking enzymes are discussed. Cell wall proteins function as cross-linking enzymes, structural elements, adhesins, and environmental stress sensors and protect the cell from environmental changes.

A case of ragweed Ambrosia artemisiifolia L. Invasive exotic species pose a growing threat to the economy, public health, and ecological integrity of nations worldwide. Explaining and predicting the spatial distribution of invasive exotic species is of great importance to prevention and early warning efforts. We are investigating the potential distribution of invasive exotic species, the environmental factors that influence these distributions, and the ability to predict them using statistical and information-theoretic approaches.

However, for most species, absence data are not available. Presented with the challenge of developing a model based on presence-only information, we developed an improved logistic regression approach using Information Theory and Frequency Statistics to produce a relative suitability map. This paper generated a variety of distributions of ragweed Ambrosia artemisiifolia L. Our logistic regression model was based on Akaike's Information Criterion AIC from a suite of ecologically reasonable predictor variables.

Based on the results we provided a new Frequency Statistical method to compartmentalize habitat-suitability in the native range. Finally, we used the model and the compartmentalized criterion developed in native ranges to "project" a potential distribution onto the exotic ranges to build habitat-suitability maps.

Common ragweed Ambrosia artemisiifolia L. Ragweed pollen is the main cause of allergenic diseases in Northern America, and the weed has become a spreading neophyte in Europe. Climate change and air pollution are speculated to affect the allergenic potential of pollen. The objective of this study was to investigate the effects of NO2 , a major air pollutant, under controlled conditions, on the allergenicity of ragweed pollen.

Ragweed was exposed to different levels of NO2 throughout the entire growing season, and its pollen further analysed. Spectroscopic analysis showed increased outer cell wall polymers and decreased amounts of pectin. Proteome studies using two-dimensional difference gel electrophoresis and liquid chromatography-tandem mass spectrometry indicated increased amounts of several Amb a 1 isoforms and of another allergen with great homology to enolase Hev b 9 from rubber tree.

Analysis of protein S-nitrosylation identified nitrosylated proteins in pollen from both conditions, including Amb a 1 isoforms. However, elevated NO2 significantly enhanced the overall nitrosylation. Finally, we demonstrated increased overall pollen allergenicity by immunoblotting using ragweed antisera, showing a significantly higher allergenicity for Amb a 1. The data highlight a direct influence of elevated NO2 on the increased allergenicity of ragweed pollen and a direct correlation with an increased risk for human health.

Expansion and aerobiology of Ambrosia artemisiifolia L. Full Text Available [b]Introduction and objective. The purpose of this study was to survey the spread and distribution of this species in Slovakia and to analyse its airborne pollen pattern.

Aerobiological sampling was based on the analysis of pollen records at five aerobiological stations in Slovakia. Highest airborne pollen counts were recorded in Nitra, Trnava and Bratislava Monitoring Stations situated in the areas most infested by A.

Besides the most infested areas, high airborne pollen counts were also recorded in territories where the plant species was less abundant. During the study period, the intensity of [i] Ambrosia. Full Text Available The effect on Ambrosia artemisiifolia common ragweed of combining cutting and herbicide application was studied in pot experiments in Germany and Denmark in Matrigon, mesotrione in Germany and Denmark: Callisto and glyphosate in Germany: Roundup Bio were applied at 4 doses at three different timings: The plants were harvested 5 weeks after the last herbicide application.

At both sites clopyralid and mesotrione had a low efficacy on common ragweed when applied on developed plants with only minor differences in efficacy at the three timings. Application after cutting improved the efficacy of clopyralid at both sites and of mesotrione in Denmark. In Germany glyphosate had a higher efficacy on noncut plants in comparison to the cut plants, in Denmark it was vice versa.

The highest dose of glyphosate provided higher control levels on developed plants than clopyralid and mesotrione at both sites. In Denmark the highest effects were obtained shortly after cutting with the maximum dose of each herbicide and declined with time between cutting and herbicide application. In summary the results demonstrated that herbicides can be applied shortly after cutting without loss of efficacy.

Agricultural fields under integrated pest management and ecological farming were monitored The aim was to assess the performance of chemical and other control measures against ragweed under farming conditions of the region.

These parameters were ranked and, by way of multiplication, merged into one single value, which can be expressed as degree of a defined intense infestation level. Such approach is considered to be useful to track recuperation efforts and estimate control efficiency by comparing pre and post measure infestation status. The index is applied to results of the growing season, which is illustrated by some examples.

Molecular and immunological characterization of ragweed Ambrosia artemisiifolia L. Full Text Available Climate change and air pollution, including ozone is known to affect plants and might also influence the ragweed pollen, known to carry strong allergens. We compared the transcriptome of ragweed pollen produced under ambient and elevated ozone by sequencing.

Pollen surface was examined by scanning electron microscopy and attenuated total reflectance-Fourier transform infrared spectroscopy ATR-FTIR, and phenolics were analysed by high-performance liquid chromatography.

Elevated ozone had no influence on the pollen size, shape, surface structure or amount of phenolics. Transcriptomic analyses showed changes in expressed-sequence tags ESTs, including allergens. The data highlight a direct influence of ozone on the exine components and transcript level of allergens. As the total protein amount of Amb a 1 was not altered, a direct correlation to an increased risk to human health could not be derived. Additional, the sequencing contributes to the identification of stress-related transcripts in mature pollen that could be grouped into distinct gene ontology terms.

Climate change and air pollution, including ozone is known to affect plants and might also influence the ragweed pollen, known to carry strong allergens. Pollen surface was examined by scanning electron microscopy and attenuated total reflectance-Fourier transform infrared spectroscopy ATR-FTIR , and phenolics were analysed by high-performance liquid chromatography.

Transcriptomic analyses showed changes in expressed-sequence tags ESTs , including allergens. New Sesquiterpenoids from Ambrosia artemisiifolia L. Full Text Available A new pseudoguaianolide 1 and two new guaiane-type sesquiterpene glucosides 2 and 3, were isolated from the aerial parts of Ambrosia artemisiifolia L together with two known sesquiterpene dilactones 4 and 5.

The isolated compounds were evaluated for cytotoxicity against human promyelocytic leukemia HL cell lines in vitro, but were all inactive. Results showed that increasing density of A. There was no significant impact on peanut plant height. Exponential regression model was the best in describing the relationship between A. Immunoproteomic characterization of Ambrosia artemisiifolia pollen allergens in canine atopic dermatitis.

Short ragweed Ambrosia artemisiifolia pollen represents one of the major seasonal sources of allergenic pollen proteins in Europe, particularly in the Pannonian valley of the Balkan region.

Therefore, characterization of Ambrosia artemisiifolia pollen components, in terms of defining major and minor allergens that induce clinically manifested allergic reaction in dogs, is important for valid diagnosis and efficient therapy.

This study has, for the first time, characterized and identified major Ambrosia artemisiifolia allergens in CAD, using an immunoproteomic approach. To assess the prevalence of specific IgE in electrophoretically separated ragweed pollen proteins, individual reactivity of sera from dogs with CAD was analyzed and compared to the reactivity of sera from healthy dogs in the non-reducing conditions, which were found optimal for specific canine IgE detection.

The most prominent ragweed proteins in CAD, represent, as in humans, variants of all five isoallergens of the Amb a 1 group pectate lyase: Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. New sets of genomic and expressed sequence tag EST based simple sequence repeats SSRs markers were developed in this species using three approaches. After validation, 13 genomic SSRs and 13 EST-SSRs were retained and used to characterize the genetic diversity and population genetic structure of Ambrosia artemisiifolia populations from the native North America and invasive Europe ranges of the species.

Analysing the mating system based on maternal families did not reveal any departure from complete allogamy and excess homozygosity was mostly due the presence of null alleles. High genetic diversity and patterns of genetic structure in Europe suggest two main introduction events followed by secondary colonization events. Cross-species transferability of the newly developed markers to other invasive species of the Ambrosia genus was assessed.

Cloning, expression, and characterization of pollen allergens from Humulus scandens Lour Merr and Ambrosia artemisiifolia L. The allergen genes were selectively amplified in the weed pollen cDNA pool by using a special PCR profile, with the primers designed by a modeling procedure.

Following truncated gene cloning and confirmation of the pollen source, unknown 3'cDNA ends were identified by using the 3'-RACE method. The gene function conferred by the full-length coding region was evaluated by a homologue search in the GenBank database. Recombinant proteins expressed in Escherichia coli pET RosettaBlue cells were subsequently characterized by N-terminal end sequencing, IgE binding, and crossreactivity.

Three full-length cDNAs were obtained in each weed. Five recombinant proteins were abundantly expressed in nonfusion forms and were confirmed by using the N-terminal end sequence identity. Sera from patients who were allergic to A artemisiifolia reacted not only with rAmb a 8 D03 derived from A artemisiifolia , but also with recombinant protein rHum s 1 LCM9 derived from H scandens, which confirmed the allergenicity and cross-reactivity of the recombinant proteins from the 2 sources.

Comparison of the degenerate primers used for truncated gene cloning with the full-length cDNA demonstrated that alternative nucleotide degeneracy occurred. This study demonstrates a useful method for cloning homologous allergen genes across different species, particularly for little-studied species. The weeding of Ambrosia artemisiifolia and sanitary risks. Ambrosia artemisiifolia is a potentially allergenic annual herbaceous plant coming from North America and widespread in Italy, where it can be easily seen since May-April.

Its pollination is mainly windborne and each plant is able to produce billions of pollen grains. The pollen peaks are in the hottest days in the absence of rain and wind.

In susceptible individuals, the great amount of pollen produced by this species may cause rhinitis and severe asthma attacks. Some allergic subjects can manifest disorders already at a concentration of a few granules per cubic metre. Chemical control is often practiced on a large scale and uses herbicides. A major risk is the result of the unprofessional use of chemicals by the population, especially in residential or very busy areas eg railways, urban areas. In this paper we propose preventive measures of chemical hazards that may be resulting from the excessive use of plant protection products.

Its pollen can be transported over large distances and has been recognized as a significant cause of hayfever and asthma D'Amato et al.

RegCM4 was adapted to incorporate the pollen emissions from ORCHIDEE French Global Land Surface Model and a pollen tracer model for describing pollen convective transport, turbulent mixing, dry and wet deposition over extensive domains, using consistent assumption regarding the transport of multiple species Fabien et al.

We performed two families of recent-past simulations on the Euro-Cordex domain simulation for future condition is been considering. The observations were divided into two groups and used for calibration and validation separately. A wide range of possible calibration coefficients were tested for each calibration station, making the bias between observations and simulations within an admissible value then.

Gradual loss of genetic diversity of Ambrosia artemisiifolia L. Over the last two decades, while expanding toward southern parts of Serbia, this common ragweed has become a very troublesome plant species in the whole country. Considering the importance of genetic studies in understanding of invasive species, our main objectives in this study were to analyze the genetic diversity and genetic structure of Ambrosia artemisiifolia populations from Central Serbia, a relatively recently invaded region.

Comparing values of genetic measures obtained by microsatellite analyses, a number of differences were detected in genetic diversity between sampled populations. Allelic richness-r ranged from 5. We observed greater genetic variability in populations from the northern part of investigated area than in southern populations.

Data obtained for analyses of differentiation and gradual losses of genetic diversity of sampled populations provides useful information about invasion dynamics of common ragweed in recently invaded region. Changes in defense of an alien plant Ambrosia artemisiifolia before and after the invasion of a native specialist enemy Ophraella communa.

Full Text Available The evolution of increased competitive ability hypothesis EICA predicts that when alien plants are free from their natural enemies they evolve lower allocation to defense in order to achieve a higher growth rate.

If this hypothesis is true, the converse implication would be that the defense against herbivory could be restored if a natural enemy also becomes present in the introduced range. We tested this scenario in the case of Ambrosia artemisiifolia common ragweed - a species that invaded Japan from North America. We collected seeds from five North American populations, three populations in enemy free areas of Japan and four populations in Japan where the specialist herbivore Ophraella communa naturalized recently.

Using plants grown in a common garden in Japan, we compared performance of O. Conversely, in locations where the herbivore O. These results strengthen the case for EICA and suggest that defense levels of alien populations can be recuperated rapidly after the native specialist becomes present in the introduced range.

Our study implies that the plant defense is evolutionary labile depending on plant-herbivore interactions. Northern range edge equilibrium of Ambrosia artemisiifolia L. Full Text Available Description of the subject.

The geographic distributions of a species, be it native or alien, is expected to be limited at some point by environmental conditions.

In this situation, a range edge equilibrium REE takes place, i. The occurrence of REE has never been tested for an invasive species. In Western Europe, the invasive weed Ambrosia artemisiifolia L. It is currently unknown whether the range has reached a limit or not. Information about how the species responds to sunflower competition is also lacking.

This work addressed two questions: Has the northern part of A. Plots were established in an agricultural field ca. The following year, the population growth rates and the soil seed bank were assessed. The species established populations with relatively high growth rates and soil seed bank. Sunflower competition did not have a significant impact on plant performance.

The results invalidate the hypothesis of equilibrium at the current margin of A. Let native species take their course: Ambrosia artemisiifolia replacement during natural or ;artificial; succession. In this study, we considered the time-span in which the species is suppressed during active restoration actions and passive spontaneous vegetation recovery. In particular, we envisaged that A. Three different treatments were applied within an abandoned quarry area commonly invaded by A. We determined the effect of mixtures of grassland species, established from native hayseed or from a commercial seed mixture, on A.

The results demonstrated that, after the first growing season, compared with spontaneous succession, both commercial seed and hayseed resulted in a strong reduction of A.

After the second growing season, A. This study indicated that both active and passive vegetation recovery by niche filling and competitive exclusion could be used as methods individually or in combination with other methods, such as mowing and biological control, to suppress A. Scientific Opinion on the effect on public or animal health or on the environment on the presence of seeds of Ambrosia spp. The genus Ambrosia Asteraceae family is distributed worldwide. Ambrosia artemisiifolia common ragweed has heavily colonised several areas of South-East Europe.

Life history trait differentiation and local adaptation in invasive populations of Ambrosia artemisiifolia in China. Local adaptation has been suggested to play an important role in range expansion, particularly among invasive species.

However, the extent to which local adaptation affects the success of an invasive species and the factors that contribute to local adaptation are still unclear. This study aimed to investigate a case of population divergence that may have contributed to the local adaptation of invasive populations of Ambrosia artemisiifolia in China.

Common garden experiments in seven populations indicated clinal variations along latitudinal gradients, with plants from higher latitudes exhibiting earlier flowering and smaller sizes at flowering. In reciprocal transplant experiments, plants of a northern Beijing origin produced more seeds at their home site than plants of a southern Wuhan origin, and the Wuhan-origin plants had grown taller at flowering than the Beijing-origin plants in Wuhan, which is believed to facilitate pollen dispersal.

These results suggest that plants of Beijing origin may be locally adapted through female fitness and plants from Wuhan possibly locally adapted through male fitness.

Selection and path analysis suggested that the phenological and growth traits of both populations have been influenced by natural selection and that flowering time has played an important role through its direct and indirect effects on the relative fitness of each individual. This study evidences the life history trait differentiation and local adaptation during range expansion of invasive A.

New insights into ragweed pollen allergens. Pollen allergens from short ragweed Ambrosia artemisiifolia cause severe respiratory allergies in North America and Europe. To date, ten short ragweed pollen allergens belonging to eight protein families, including the recently discovered novel major allergen Amb a 11, have been recorded in the International Union of Immunological Societies IUIS allergen database. With evidence that other components may further contribute to short ragweed pollen allergenicity, a better understanding of the allergen repertoire is a requisite for the design of proper diagnostic tools and efficient immunotherapies.

This review provides an update on both known as well as novel candidate allergens from short ragweed pollen, identified through a comprehensive characterization of the ragweed pollen transcriptome and proteome. Common ragweed invasion in Sweden: Common ragweed Ambrosia artemisiifolia is a neophyte from North America that has spread rapidly throughout Europe. Because the pollen of common ragweed is highly allergic, many countries have adopted containment and mitigation measures.

The neophyte has only recently established flowering populations in Sweden. We use this well documented case to study the early impacts of an invasive species on human health. Our identification strategy relies on spatial and temporal variation in common rag Full Text Available Germination characteristics and frost tolerance of seedlings are crucial parameters for establishment and invasion success of plants.

Within this study, we investigated germination characteristics of Ambrosia artemisiifolia L. We determined germination rates and speed under different temperature conditions. From these parameters we calculated minimal, optimal, and maximal temperature for germination.

We also investigated the frost tolerance of seedlings. The European populations were characterized by a higher fitness with higher germination rates and germination speed, increased biomass and higher frost tolerance of seedlings.

Furthermore, the temperature niche width for germination was significantly broader for the European populations. The increased frost tolerance of the European populations might allow germination earlier in the year which may subsequently lead to higher biomass allocation — due to a longer growing period — and result in higher pollen and seed production. The increase in germination rates, germination speed and seedling frost tolerance might result in a higher fitness of the European populations which may facilitate further successful invasion and sharpen the existing problems.

Effects of seed traits variation on seedling performance of the invasive weed, Ambrosia artemisiifolia L. Seedling performance can determine the survival of a juvenile plant and impact adult plant performance. Understanding the factors that may impact seedling performance is thus critical, especially for annuals, opportunists or invasive plant species. Seedling performance can vary among mothers or populations in response to environmental conditions or under the influence of seed traits.

However, very few studies have investigated seed traits variations and their consequences on seedling performance. Specifically, the following questions have been addressed by this work: With seeds from nine Western Europe ruderal populations, seed traits that can influence seedling development were measured.

The seeds were sown into growth chambers with warmer or colder temperature treatments. During seedling growth, performance-related traits were measured.

A high variability in seed traits was highlighted. Variation was determined by the mother identity and population, but not latitude. Together, the temperature, population and the identity of the mother had an effect on seedling performance.

Seed traits had a relative impact on seedling performance, but this did not appear to be temperature dependent. Seedling performance exhibited a strong plastic response to the temperature, was shaped by the identity of the mother and the population, and was influenced by a number of seed traits.

Prevalence of sensitization to weed pollens of Humulus scandens,Artemisia vulgaris, and Ambrosia artemisiifolia in northern China.

Weed pollens are common sources of allergens worldwide. The prevalence of weed pollen sensitization is not yet fully known in China. The purpose of this study was to investigate the prevalence of sensitization to weed allergens from Artemisia, Ambrosia ,and Humulus in northern China. A total of subjects aged from 5 to 68 years visiting our clinic from June to October underwent intradermal testing using a panel of 25 allergen sources. Subjects with positive skin responses to any pollen were further tested for their serum concentrations of IgE antibodies against Artemisia vulgaris, Ambrosia artemisiifolia ,and Humulus scandens,and against the purified allergens,Art v 1 and Amb a 1.

Of 1 subjects, had positive intradermal reactions to pollen and donated serum for IgE testing. The prevalence of positive intradermal responses to pollens of Artemisia sieversiana,Artemisia annua,A. Among the intradermal positive subjects,the prevalence of specific IgE antigens to A. The prevalence of specific IgE antigens to the allergen Art v 1 was The correlation between the presence of IgE antibodies specific to A.

There were no correlations between the presence of IgE antibodies to H. The intradermal prevalence of weed pollen sensitization among allergic subjects in northern China is about Correlations of specific IgE antibodies suggest that pollen allergens from Artemisia and Humulus are independent sources for primary sensitization.

Mesoscale atmospheric transport of ragweed pollen allergens from infected to uninfected areas. Allergenic ragweed Ambrosia spp. However, the action of air temperature, humidity and solar radiation on pollen grains in the atmosphere could impact on the ability of long distance transported LDT pollen to maintain allergenic potency. Here, we report that the major allergen of Ambrosia artemisiifolia pollen Amb a 1 collected in ambient air during episodes of LDT still have immunoreactive properties.

The amount of Amb a 1 found in LDT ragweed pollen grains was not constant and varied between episodes. In addition to allergens in pollen sized particles, we detected reactive Amb a 1 in subpollen sized respirable particles. These findings suggest that ragweed pollen grains have the potential to cause allergic reactions, not only in the heavily infested areas but, due to LDT episodes, also in the regions unaffected by ragweed populations. Glyphosate resistance in common ragweed Ambrosia artemisiifolia L.

Glyphosate is one of the most commonly used broad-spectrum herbicides over the last 40 years. Due to widespread adoption of glyphosate-resistant GR crop technology, especially, corn, cotton, and soybean, several weed species in agronomic situations have developed resistance to this herbicide.

Glyphosate resistance in giant ragweed Ambrosia trifida L. A giant ragweed population from a glyphosate-resistant GR soybean field in Mississippi was suspected to be resistant to glyphosate. Greenhouse and laboratory studies were conducted to confirm and quantify the magnitude of glyphosate resistance in the giant ragweed population and to elucidate the p Full Text Available Only a limited spectrum of active substances is available for weed control in leguminous plants and sunflowers.

Since the official plant protection service in Brandenburg conducts herbicide field trials in these crop species in the region around Drebkau for the investigation of practicable approaches for control of Ambrosia artemisiifolia. For the cultivation of lupins only pre-emergence herbicides are registered. Due to the high density of A. Likewise, the performance of authorised herbicides in sunflowers is insufficient. In the region concerned cultivation of grain legumes and sunflowers is limited in areas with high coverage rate of A.

Full Text Available Since the beginning of common ragweed registration in North Rhine-Westphalia in there have been ragweed records, among them 31 populations with more than individuals. Common ragweed is not yet established in North Rhine-Westphalia but seems to do very well on sandy soils in the Lowland. North Rhine-Westphalia is tackling common ragweed in an early stage of invasion and will continue the strategy of rapid response to achieve a total eradication.

Thirty-three countries have already signed the Memorandum of Understanding and over researchers with specialists in weed research, invasive alien species management, ecology, aerobiology, allergology and economics are registered participants of SMARTER.

COST Actions interlink nationally funded research projects and enable and finance conferences, working groups, training schools and research exchanges. SMARTER aims to initiate and develop long-term and sustainable control methods, to integrate these into existing mechanical and chemical control measures, and to quantify the success of these measures both for agriculture and health.

The focus is on biological control methods with insects and fungi especially using alien species from the area of origin of Ambrosia and vegetation management to achieve a competitive plant cover.

For this, we develop and parameterize models, starting from the population dynamics of Ambrosia , on the impact of control measures on the frequency and distribution of Ambrosia and finally on pollen counts and allergy occurrences, each with both ecological and economic components. The necessary data are derived from the many experiments that we carry out in well-coordinated studies across Europe. SMARTER will allow the various stakeholders to select optimal habitat- and region-specific combinations of control methods.

After an introduction and overview of the structure and the state of the Action, we briefly describe two planned activities typical for our Action, a study on the population dynamics of Ambrosia in different climates and habitats in Europe as a basis for estimating the efficiency of control measures, and an interdisciplinary study to clarify the impact the of North American native Ambrosia leaf beetle Ophraella communa Coleoptera. Climate-change-induced range shifts of three allergenic ragweeds Ambrosia L.

Full Text Available Invasive allergenic plant species may have severe health-related impacts. In this study we aim to predict the effects of climate change on the distribution of three allergenic ragweed species Ambrosia spp. We estimate that by year , the distribution range of all three ragweed species increases towards Northern and Eastern Europe under all climate scenarios. We conclude that areas in Europe affected by severe ragweed associated allergy problems are likely to increase substantially by year , affecting millions of people.

To avoid this, management strategies must be developed that restrict ragweed dispersal and establishment of new populations. Precautionary efforts should limit the spread of ragweed seeds and reduce existing populations. Only by applying cross-countries management plans can managers mitigate future health risks and economical consequences of a ragweed expansion in Europe. Invasive allergenic plant species may have severe health-related impacts.

We quantify the extent of the increase in 'high allergy risk' HAR areas, i. Effects of climate change and seed dispersal on airborne ragweed pollen loads in Europe. Common ragweed Ambrosia artemisiifolia is an invasive alien species in Europe producing pollen that causes severe allergic disease in susceptible individuals.

Ragweed plants could further invade European land with climate and land-use changes. However, airborne pollen evolution depends not only on plant invasion, but also on pollen production, release and atmospheric dispersion changes. To predict the effect of climate and land-use changes on airborne pollen concentrations, we used two comprehensive modelling frameworks accounting for all these factors under high-end and moderate climate and land-use change scenarios.

We estimate that by airborne ragweed pollen concentrations will be about 4 times higher than they are now, with a range of uncertainty from 2 to 12 largely depending on the seed dispersal rate assumptions. About a third of the airborne pollen increase is due to on-going seed dispersal, irrespective of climate change.

The remaining two-thirds are related to climate and land-use changes that will extend ragweed habitat suitability in northern and eastern Europe and increase pollen production in established ragweed areas owing to increasing CO2. Therefore, climate change and ragweed seed dispersal in current and future suitable areas will increase airborne pollen concentrations, which may consequently heighten the incidence and prevalence of ragweed allergy.

Full Text Available Since the common ragweed , Ambrosia artemisiifolia , which was introduced from North America has also been found in Bavaria in larger stocks and has an increasing tendency to spread.

After receiving the report of the Bavarian Ministry of Health, the Bavarian Parliament addressed the implications for health. There was consensus across all political groups to combat the plant. The 96 district administration authorities, which each have a trained ragweed officer, report to the registration office on new verified ragweed locations with more than plants.

The reports of common ragweed stands are filed by citizens or through research by the district administration authorities, who are also responsible for supporting the fight against stocks.

On behalf of the Bavarian Ministry of Health, the Working Group Biodiversity monitors the situation and finds many new locations. Since , new common ragweed stocks were registered. After control measures there are currently known remaining stocks. Since , however, the populated area has tripled.

This means that the control measures need further improvement. This is especially true for the common ragweed stocks along roadsides where the plants have increased massively in recent years.

Sustainable control has proved to be particularly difficult. Ragweed -induced allergic rhinoconjunctivitis: Ragweed -induced allergic rhinoconjunctivitis has long been seen as a major immunologic condition in Northern America with high exposure and sensitization rates in the general population.

The invasive occurrence of ragweed A. Possible explanations for its worldwide spread are climate change and urbanization, as well as pollen transport over long distances by globalized traffic and winds.

Due to the increasing disease burden worldwide, and to the lack of a current and comprehensive overview, this study aims to review the current and emerging treatment options for ragweed -induced rhinoconjunctivitis. Sound clinical evidence is present for the symptomatic treatment of ragweed -induced allergic rhinoconjunctivitis with oral third-generation H1-antihistamines and leukotriene antagonists.

The topical application of glucocorticoids has also been efficient in randomized controlled clinical trials. Combined approaches employing multiple agents are common. The mainstay of causal treatment to date, especially in Northern America, is subcutaneous immunotherapy with the focus on the major allergen, Amb a 1.

Beyond this, growing evidence from several geographical regions documents the benefit of sublingual immunotherapy. Future treatment options promise more specific symptomatic treatment and fewer side effects during causal therapy. Rapid, automated separation of specific bacteria from lake water and sewage by flow cytometry and cell sorting.

The use of fluorescence-activated flow cytometric cell sorting to obtain highly enriched populations of viable target bacteria was investigated. Preliminary studies employed mixtures of Staphylococcus aureus and Escherichia coli. This was possible even when S.

Cell sorting was also tested for the ability to recover E. The environmental samples were challenged with fluorescently labelled antibodies specific for E. Biodegradation studies and sequencing of microcystin-LR degrading bacteria isolated from a drinking water biofilter and a fresh water lake.

The presence of microcystin-LR -degrading bacteria in an active anthracite biofilter and in Lake Mead, Nevada was investigated. Four bacterial isolates from enrichment culture were identified using 16S rRNA analysis. Microcystin biodegradation tests were performed with both, the enrichment cultures and the respective isolates, using microcystin alone and acetate as carbon sources.

A newly recognized microcystin-degrading bacterium, Morganella morganii, was isolated from the biofilter and from Lake Mead. The results of the biodegradation tests indicated that addition of a carbon source acetate , significantly repressed the degradation of microcystin-LR.

The findings of this study inform on the prevalence of microcystin-degrading bacteria in the environment indicating bioaugmentation may not be needed, if biofiltration is used to remove microcystin from waters. The results also imply that, in a biofilter, biodegradable naturally organic matter NOM and microcystin will compete and therefore lower toxin removals are likely in waters with higher NOM content.

The feasibility of removing microcystin by biofiltration depends on the toxin concentration and the concentration of biodegradable carbon sources in the biofilter. Depth profiles of spectral and hydrological characteristics of water and their relation to abundances of green sulfur bacteria in the stratified lakes of the White Sea.

We analyze the results received from two expeditions performed in August-September , August-September and February in the Kandalaksha Bay of the White Sea. Depth profiles of hydrological characteristics and optical properties of water were recorded for five marine lakes being on different stages of isolation from the White Sea. Those relic lakes demonstrate a tendency to meromixis and are characterized by apparent stratification of the water bodies from the brackish top layer to the bottom salt water.

Maximal concentrations of anoxygenic phototrophs green sulfur bacteria were found at depths close to the redox interface in all the studied lakes.

To discriminate differently pigmented groups of microorganisms the fluorescence emission spectra of bacteriochlorophylls from the living cells were used. We puzzle out the data on light spectrum propagation through the water body in each lake using optical properties of water attenuation spectra in the UV, visible and NIR ranges, as well as direct measurements of the total irradiances at various depths.

The changes in optical characteristics of water in the stratified reservoirs due to cromophoric dissolved organic matter CDOM and microbial pigments affect the light intensity and its spectral distribution at each water layer thus influencing the living conditions for differently pigmented phototrophic microorganisms and determining the composition of microbial community.

Effect of cadmium on lake water bacteria as determined by the luciferase assay of adenosine triphosphate. A firefly luciferase assay of bacterial adenosine triphosphate ATP was developed to measure the toxic effects of cadmium ions on aquatic organisms. The bacteria , which belonged mainly to the families Enterobacteriaceae and Pseudomonadaceae, exhibited varying degrees of resistance to up to ppm cadmium when grown in a glucose-salts medium at pH 6.

Among the organisms tested, cadmium resistance decreased in the following order: A rise in the pH of the growth medium from 5 to 7 resulted in increased toxicity of cadmium. A guide to the natural history of freshwater lake bacteria.

Freshwater bacteria are at the hub of biogeochemical cycles and control water quality in lakes. Despite this, little is known about the identity and ecology of functionally significant lake bacteria. Molecular studies have identified many abundant lake bacteria , but there is a large variation in the taxonomic or phylogenetic breadths among the methods used for this exploration. Because of this, an inconsistent and overlapping naming structure has developed for freshwater bacteria , creating a significant obstacle to identifying coherent ecological traits among these groups.

A discourse that unites the field is sorely needed. Here we present a new freshwater lake phylogeny constructed from all published 16S rRNA gene sequences from lake epilimnia and propose a unifying vocabulary to discuss freshwater taxa. With this new vocabulary in place, we review the current information on the ecology, ecophysiology, and distribution of lake bacteria and highlight newly identified phylotypes. In the second part of our review, we conduct meta-analyses on the compiled data, identifying distribution patterns for bacterial phylotypes among biomes and across environmental gradients in lakes.

We conclude by emphasizing the role that this review can play in providing a coherent framework for future studies. Effects of water -column mixing on bacteria , phytoplankton, and rotifers under different levels of herbivory in a shallow eutrophic lake. Water -column mixing is known to have a decisive impact on plankton communities.

The underlying mechanisms depend on the size and depth of the water body, nutrient status and the plankton community structure, and they are well understood for shallow polymictic and deep stratified lakes.

Two consecutive mixing events of similar intensity under different levels of herbivory were performed in enclosures in a shallow, but periodically stratified, eutrophic lake , in order to investigate the effects of water -column mixing on bacteria abundance, phytoplankton abundance and diversity, and rotifer abundance and fecundity. When herbivory by filter-feeding zooplankton was low, water -column mixing that provoked a substantial nutrient input into the euphotic zone led to a strong net increase of bacteria and phytoplankton biomass.

Phytoplankton diversity was lower in the mixed enclosures than in the undisturbed ones because of the greater contribution of a few fast-growing species.

After the second mixing event, at a high biomass of filter-feeding crustaceans, the increase of phytoplankton biomass was lower than after the first mixing, and diversity remained unchanged because enhanced growth of small fast-growing phytoplankton was prevented by zooplankton grazing. Bacterial abundance did not increase after the second mixing, when cladoceran biomass was high. Changes in rotifer fecundity indicated a transmission of the phytoplankton response to the next trophic level.

Our results suggest that water -column mixing in shallow eutrophic lakes with periodic stratification has a strong effect on the plankton community via enhanced nutrient availability rather than resuspension or reduced light availability. This fuels the basis of the classic and microbial food chain via enhanced phytoplankton and bacterial growth, but the effects on biomass may be damped by high levels of herbivory. Environmental factors influencing the distribution of ammonifying and denitrifying bacteria and water qualities in 10 lakes and reservoirs of the Northeast, China.

This study presents seasonal and spatial variations of the ammonifying bacteria AB and denitrifying bacteria DNB and physicochemical parameters in 10 lakes and reservoirs in the northeast of China. Water samples were collected in winter January , spring March , summer July and fall November in Seasonally, the levels of AB presents gradually upward trend from winter to summer, and declines in fall and DNB were higher in spring and fall than summer and lowest in winter.

Thirteen water quality tests measuring five categories of pollution were conducted twice monthly from May, to April, at eight locations on Lake Sidney Lanier to establish baseline data and detect trends. Additionally, sediment and water samples were analyzed for ten toxic metals. Sampling stations were located at or near the point of entry of streams into the Lake.

Oxygen demanding pollutants were highest in urban streams and phosphorus and nitrogen concentrations were highest in streams having poultry processing operations within their watersheds. Indicators of siltation increased coincidentally with highway construction in one watershed. Fecal coliform bacteria counts decreased at Flat Creek and increased in the Chattahoochee River. Zinc and copper occurred in water samples at levels of detectability.

Sediment samples from several locations contained metal concentrations which warrant further study. Streams are an important sink for anthropogenic N owing to their hydrological connections with terrestrial systems, but main factors influencing the community structure and abundance of denitrifiers in stream water remain unclear. To elucidate the potential impact of varying water properties of different streams on denitrifiers, the abundance and community of three denitrifying genes coding for nitrite nirK, nirS and nitrous oxide nosZ reductase were investigated in 11 streams inlets at the north part of Dianchi Lake.

The DGGE results showed the significant pairwise differences in community structure of nirK, nirS, and nosZ genes among different streams. The results of redundancy analysis RDA confirmed that nitrogen and phosphorus concentrations, pH, and temperature in waters were the main environmental factors leading to a significant alteration in the community structure of denitrifiers among different streams. Bacteria , archaea, and crenarchaeota in the epilimnion and hypolimnion of a deep holo-oligomictic lake.

In a deep, subalpine holo-oligomictic lake , the relative abundance of Archaea and Crenarchaeota, but not that of Bacteria , increases significantly with depth and varies seasonally. Cell-specific prokaryotic productivity is homogeneous along the water column. The concept of active Archaea observed in the deep ocean can therefore be extended to a deep oxic lake.

Antibiotic concentration and antibiotic-resistant bacteria in two shallow urban lakes after stormwater event. Stormwater runoff is generally characterized as non-point source pollution. In the present study, antibiotic concentration and antibiotic susceptibilities of cultivable heterotrophic bacteria were investigated in two small shallow urban lakes before and after strong storm event.

In general, the frequencies of bacteria showing resistance to nine antibiotics increased after storm event. Based on the 16S rRNA genes of 50 randomly selected isolates from each water sample of two lakes , Aeromonas and Bacillus were dominant genera in samples from two lakes , while genera Proteus and Lysinibacillus were the third abundant genera in Lake Xuanwu and Wulongtu, respectively. Presences of nine antibiotic resistance genes ARGs in the isolates were detected and most of these isolates harbored at least two ARGs with different functions.

The detection frequency of ARGs in Gram-negative isolates was higher than that in Gram-positive isolates. Our results indicate that strong storm events potentially contribute to the transfer of ARGs and antibiotic-resistant bacteria from land-sewer system to the urban Lakes. Cold-active halophilic bacteria from the ice-sealed Lake Vida, Antarctica.

Lake Vida is a large, permanently ice-covered lake in the Victoria Valley of the McMurdo Dry Valleys, Antarctica and is unique among Dry Valley lakes because it is ice-sealed, with an ice-cover of nearly 19 m. Enrichment cultures of melt- water from Lake Vida Of these, one strain grew at -8 degrees C and the four others at -4 degrees C.

Phylogenetic analysis revealed the Lake Vida isolates to be Gammaproteobacteria, related to species of Psychrobacter and Marinobacter. This is the first report of pure cultures of bacteria from Lake Vida, and the isolates displayed a phenotype consistent with life in a cold hypersaline environment. The spatial distribution of enteric bacteria in the Jordan River- Lake Kinneret contact zone. Lake Kinneret, in the north of Israel, is the only freshwater body in the country. It supports many activities, including recreation, tourism, and a commercial fishing industry, but its prime function is to supply water to other parts of the country.

Consequently, maintaining a high water quality of the lake is of prime importance. During this period, the river carries sediments, toxic agricultural chemicals, and allochthonous organisms, including pathogenic bacteria , into the lake. The Jordan River- Lake Kinneret contact zone is characterized by a rapid transformation from a riverine to a lacustrine water mass within m from the river mouth, with very high spatial gradients of practically all hydrodynamic, hydrophysical, hydrochemical, and microbiological parameters.

Previous measurements have shown that the distribution of enteric bacteria in the river- lake contact zone is related to the attenuation of river current flows. The aim of this study was to determine whether the change in the number of enteric bacteria fecal coliforms, Escherichia coli, and Klebsiella spp.

The data were then utilized to build a conceptual model explaining the distribution of biological pollutants bacteria in the river- lake contact zone of a shallow tropical lake , using the microbial communities of the River Jordan- Lake Kinneret contact zone, as an example.

Water -quality data collected from Lake Austin and Town Lake , following runoff, generally were not adequate to fully determine the effects of runoff on the lakes. Data collection should not to be limited to fixed-station sampling following runoff, and both lakes need to be sampled simultaneously as soon as possible following significant precipitation. From the water column of Lake Baikal, several strains of prosthecate bacteria belonging to the genera Caulobacter and Brevundimonas were isolated.

In this article, the methods applied for their isolation and cell number determination are described; the occurrence frequency and spatial distribution of these microorganisms in the lake are demonstrated.

Characterization of the species composition of cultivable and uncultivable prosthecate bacteria was carried out using the methods of traditional and molecular microbiology, respectively. A comparative phylogenetic analysis of the DNA sequences of uncultivable bacteria , which showed homology to the members of the alpha subclass of proteobacteria, was carried out.

It was demonstrated that the lake water column is inhabited by uncultivable alpha-proteobacteria of uncertain phylogenetic affinity, in addition to representatives of the species Caulobacter vibrioides and C. Lake Vostok, the largest subglacial lake in Antarctica, is separated from the surface by approximately 4 km of glacial ice.

It has been isolated from direct surface input for at least years, and the possibility of a novel environment and ecosystem therefore exists. Lake Vostok water has not been sampled, but an ice core has been recovered that extends into the ice accreted below glacial ice by freezing of Lake Vostok water.

Here, we report the recovery of bacterial isolates belonging to the Brachybacteria, Methylobacterium, Paenibacillus and Sphingomonas lineages from a sample of melt water from this accretion ice that originated m below the surface. Pore water chemistry of an alkaline rift valley lake: Lake Turkana is the largest closed basin lake in the African rift system.

It has evolved through the past years to become a moderately alkaline lake. Previous mass balance argument suggest that sulfate is removed from the lake by sulfate reduction in the sediments, and that the lake is accumulating in chloride, sodium, and alkalinity. Studies of pore water from 12 meter cores collected in November show that sulfate is reduced in the sediment column with a net production of alkalinity. Some sodium is lost from the lake and diffuses into the sediment to maintain charge balance.

Magnesium and calcium molar ratios change with depth; chloride, sodium, and alkalinity also change with depth. Methanotrophic bacteria are globally significant due to their role as a major biological sink for methane, a greenhouse gas.

These microorganisms are especially active at interfaces where methane and oxygen meet. Methanotrophs are also of environmental interest because of their ability to co-metabolize many common organic pollutants including halogenated and aromatic hydrocarbons.

Lake Mishawum in Woburn, MA, is a shallow, permanently stratified lake with an anoxic, methane-rich hypolimnion and an oxic epilimnion. This unique stratification is maintained because the bottom water continually receives inputs of salty groundwater, while the upper layer is fed by rainwater runoff.

Modeling of methane concentration profiles in the lake showed high rates of methane oxidation at the oxic-anoxic interface. Hence, methanotrophs have been postulated to be a significant and active population of the bacteria residing in the lake 's metalimnion. The diversity, abundance, and seasonal variation of methanotrophic bacteria at this interface was investigated using PCR gene diversity studies, quantitative PCR QPCR , and cultures of methane-oxidizing isolates from metalimnion water samples.

Gene diversity and isolate analyses revealed that as in other saline lakes , both Type I and Type II methanotrophs were present at the interface. QPCR studies using the methanol dehydrogenase gene showed that their populations comprised up to 15 percent of the total bacterial population in the summer months. Year long QPCR studies of methanotrophs populations at the Lake Mishawum interface indidcated that, while total bacteria numbers do not change over time, methanotroph population size varied seasonally and correlated with temperature changes in the lake.

These results suggest that methanotrophs are a diverse and highly active population in the oxic-anoxic interface of Lake Mishawum. The finding of both Type I and Type II methanotrophs at the interface calls into question the role of these two. Enrichment of sulfate-reducing bacteria and resulting mineral formation in media mimicking pore water metal ion concentrations and pH conditions of acidic pit lakes.

Acid mine drainage sites are extreme environments with high acidity and metal ion concentrations. Under anoxic conditions, microbial sulfate reduction may trigger the formation of secondary minerals as a result of H2S production and pH increase. At initial pH values of 5 and 6, sulfate reduction occurred shortly after inoculation.

Sulfate- reducing bacteria affiliated to the genus Desulfosporosinus predominated the microbial communities as shown by 16S rRNA gene analysis performed at the end of the incubation. At initial pH values of 3 and 4, sulfate reduction and cell growth occurred only after an extended lag phase, however, at a higher rate than in the less acidic assays. At the end of the growth phase, enrichments were dominated by Thermodesulfobium spp. Iron sulfides in the bulk phase were common in all assays, but specific aluminum precipitates formed in close association with cell surfaces and may function as a detoxification mechanism of dissolved Al species at low pH.

Removal and inactivation of bacteria during alum treatment of a lake. Flocculation and removal of bacteria were observed during two separate aluminum sulfate alum treatments for removal of phosphorus from a eutrophic recreational lake.

In addition, die-off and release of bacteria from alum floc were studied in columns under laboratory conditions. Membrane filtration and spread plates were used to determine concentrations of indicator species and total cultivatable bacteria , respectively. The numbers of and survival of E. Thus, the floc poses a potential human health risk if ingested by swimmers or if others use the lake as a potable water source. Bacteria and emerging chemical contaminants in the St.

Introduction Since the enactment of the Clean Water Act in , awareness of the quality of the Nation's water has continued to improve. Despite improvements to wastewater-treatment systems and increased regulation on waste discharge, bacterial and chemical contamination is still a problem for many rivers and lakes throughout the United States.

Pathogenic microorganism and newly recognized chemical contaminants have been found in waters that are used for drinking water and recreation Rose and Grimes, ; Kolpin and others, This summary of bacteria and emerging-chemical-contaminant monitoring in the St. Clair, and Wayne, and the U. We employed culture-dependent and -independent techniques to study microbial diversity in Lake Chaka, a unique hypersaline lake It is situated at 3, m above sea level in a dry climate.

The average water depth is 2 to 3 cm. Halophilic isolates were obtained from the lake water , and halotolerant isolates were obtained from the shallow sediment. The isolates exhibited resistance to UV and gamma radiation. A major change in the bacterial community composition was observed across the interface.

A similar change was also present in the archaeal community. While all archaeal clone sequences in the lake water belonged to the Halobacteriales, the majority of the sequences in the sediments were related to those previously obtained from methanogenic soils and sediments. The observed changes in the microbial community structure across the water -sediment interface were correlated with a decrease in salinity from the lake water Across the interface, the redox state also changed from oxic to anoxic and may also have contributed to the observed shift in the microbial community.

Long-term population dynamics of phototrophic sulfur bacteria in the chemocline of Lake Cadagno, Switzerland. Population analyses in water samples obtained from the chemocline of crenogenic, meromictic Lake Cadagno, Switzerland, in October for the years to were studied using in situ hybridization with specific probes. During this year period, large shifts in abundance between purple and green sulfur bacteria and among different populations were obtained.

All populations of purple sulfur bacteria showed large fluctuations in time with populations belonging to the genus Lamprocystis being numerically much more important than those of the genera Chromatium and Thiocystis. Green sulfur bacteria were initially represented by Chlorobium phaeobacteroides but were replaced by Chlorobium clathratiforme by the end of the study.

At this time, numbers of purple sulfur bacteria had decreased and those of green sulfur bacteria increased by about 1 order of magnitude and C. This major change in community structure in the chemocline was accompanied by changes in profiles of turbidity and photosynthetically available radiation, as well as for sulfide concentrations and light intensity. Overall, these findings suggest that a disruption of the chemocline in may have altered environmental niches and populations in subsequent years.

Grazing of the copepod Diaptomus connexus on purple sulphur bacteria in a meromictic salt lake. A meromictic lake ecosystem Mahoney Lake , BC, Canada was investigated to elucidate the significance of chemocline bacteria in the total carbon cycle under natural conditions. In this lake , primary production by oxygenic phototrophs was insufficient to support the observed net secondary production of the calanoid copepod Diaptomus connexus and the rotifer Brachionus plicatilis, indicating the presence of additional food sources for consumers.

Mahoney Lake harbours the densest population of phototrophic sulphur bacteria ever reported in a natural body of water. This layer is located at the interface between oxic and anoxic water layers and is dominated by the purple sulphur bacterium Amoebobacter purpureus.

The transfer rates of A. Stable stratification within the mesocosms prevented an upwelling of A. However, measurements of carbon fluxes, infrared fluorescence microscopy and stable carbon analysis provided cumulative evidence that, under in situ conditions, the cell carbon of purple sulphur bacteria indeed enters the aerobic food chain via the grazing activity of D.

Based on a two-source isotopic mixing model, A. Autumnal upwelling into oxic water layers and aggregation of A. Lake water quality mapping from Landsat. In the project described remote sensing was used to check the quality of lake waters. From the MDAS color coded maps, the lake with the worst algae problem was easily located. The lake was closely checked, and the presence of cows in the springs which fed the lake could be identified as the pollution source. The laboratory and field work involved in the lake classification project is described.

Methane oxidation in anoxic lake waters. Freshwater habitats such as lakes are important sources of methante CH4 , however, most studies in lacustrine environments so far provided evidence for aerobic methane oxidation only, and little is known about the importance of anaerobic oxidation of CH4 AOM in anoxic lake waters.

In marine environments, sulfate reduction coupled to AOM by archaea has been recognized as important sinks of CH4. More recently, the discorvery of anaerobic methane oxidizing denitrifying bacteria represents a novel and possible alternative AOM pathway, involving reactive nitrogen species e. We investigate anaerobic methane oxidation in the water column of two hydrochemically contrasting sites in Lake Lugano, Switzerland.

The South Basin displays seasonal stratification, the development of a benthic nepheloid layer and anoxia during summer and fall. The North Basin is permanently stratified with anoxic conditions below m water depth.

Both Basins accumulate seasonally South Basin or permanently North Basin large amounts of CH4 in the water column below the chemocline, providing ideal conditions for methanotrophic microorganisms.

Previous work revealed a high potential for aerobic methane oxidation within the anoxic water column, but no evidence for true AOM. Here, we show depth distribution data of dissolved CH4, methane oxidation rates and nutrients at both sites. In addition, we performed high resolution phylogenetic analyses of microbial community structures and conducted radio-label incubation experiments with concentrated biomass from anoxic waters and potential alternative electron acceptor additions nitrate, nitrite and sulfate.

First results from the unamended experiments revealed maximum activity of methane oxidation below the redoxcline in both basins. While the incubation experiments neither provided clear evidence for NOx- nor sulfate-dependent AOM, the phylogenetic analysis revealed the. Iron-oxidizing bacteria are present within the top 2 m but not always at the surface and near the water table-capillary fringe of the vegetated Nordic uranium deposit, Elliot Lake , Ontario, Canada.

They are distributed uniformly in the top 0. The locations of these bacteria correlate with zones of pyrite oxidation as delineated in previous studies by the formation of soluble iron and sulfate.

Heterotrophic bacteria are also present in the tailings, with greatest concentrations at the surface and near the water table-capillary fringe. Sulfate-reducing bacteria were detected in the soil and peat at the base of the tailings.

The results of this study suggest that the establishment of vegetation directly upon the tailings surface does not arrest bacterial pyrite oxidation. Demonstration of antifreeze protein activity in Antarctic lake bacteria. Antifreeze proteins AFPs are a structurally diverse group of proteins that have the ability to modify ice crystal structure and inhibit recrystallization of ice.

AFPs are well characterized in fish and insects, but very few bacterial species have been shown to have AFP activity to date. Eight hundred and sixty six bacterial isolates were cultivated. A novel AFP assay, designed for high-throughput analysis in Antarctica, demonstrated putative activity in of the cultures.

Subsequent analysis of the putative positive isolates showed 19 isolates with significant recrystallization inhibition RI activity. They belong to genera from the alpha- and gamma-Proteobacteria, with genera from the gamma-subdivision being predominant. The 19 AFP-active isolates were isolated from four physico-chemically diverse lakes. Ace Lake and Oval Lake were both meromictic with correspondingly characteristic chemically stratified water columns.

Pendant Lake was a saline holomictic lake with different chemical properties to the two meromictic lakes. Triple Lake was a hypersaline lake rich in dissolved organic carbon and inorganic nutrients. The environments from which the AFP-active isolates were isolated are remarkably diverse.

It will be of interest, therefore, to elucidate the evolutionary forces that have led to the acquisition of functional AFP activity in microbes of the Vestfold Hills lakes and to discover the role the antifreezes play in these organisms. Influence of lake morphology on water quality. Lakes are seriously affected due to urban pollution. The study of the morphological features of a lake system helps to identify its environmental status. The objective of the present study is to analyse the influence of morphometry on water quality in a lake Akkulam-Veli Lake , Thiruvananthapuram, Kerala.

The morphological features namely mean depth, surface area, volume, shoreline length, shoreline development and index of basin permanence have been evaluated. Correlation analysis has been conducted to determine the relationship between morphological features and water quality. Regression analysis has been conducted to find out the extent of influence of morphometric features on water quality.

The study revealed that the lake is less affected by wind-induced wave action due to various reasons. The depth and volume have significant role in the water quality. The nitrogen fixation of blue green algae can be observed from the morphological features.

The morphology has greater role in the water quality of a lake system. Carbon isotope fractionation by anoxygenic phototrophic bacteria in euxinic Lake Cadagno. Anoxygenic phototrophic bacteria utilize ancient metabolic pathways to link sulfur and iron metabolism to the reduction of CO2. In meromictic Lake Cadagno, Switzerland, both purple sulfur PSB and green sulfur anoxygenic phototrophic bacteria GSB dominate the chemocline community and drive the sulfur cycle.

Here, these differences in C-isotope fractionation are used to constrain the relative input of various anoxygenic phototrophs to the bulk community C-isotope signal in the chemocline. We sought to determine whether a distinct isotopic signature of GSB and PSB in the chemocline persists in the settling fraction and in the sediment.

To answer these questions, we also sought investigated C-isotope fractionation in the water column, settling material, and sediment of Lake Cadagno, compared these values to C-isotope fractionation of isolated anoxygenic phototroph cultures, and took a mass balance approach to investigate relative contributions to the bulk fractionation signature.

This large fractionation between the DIC and POC was also found in culture experiments carried out with anoxygenic phototrophic bacteria isolated from the lake.

Furthermore, the contribution of PSB and GSB to bulk C-isotope fractionation in the chemocline could be traced in the settling fraction and in the sediment. Taken together with other studies, such as lipid biomarker analyzes and investigations of other stratified lakes , these results offer a firmer understanding of diagenetic influences on bacterial biomass. Water -quality and lake -stage data for Wisconsin lakes , water year The purpose of this report is to provide information about the physical, che-nical, and biological characteristics of Wisconsin lakes.

Data that have been collected at specific lakes , and information to aid in the interpretation of those data, are included in this report. Data collected includes measurements of lake stage and in- lake water quality. Graphs of Secchi depths, and total-phosphorus and chlorophyll-a concentrations versus time are included for lakes with two or more years of data. Descriptive information for each lake includes location of the lake , drainage area of the lake 's watershed, period for which data are available, revisions to previously published records, and pertinent remarks.

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Maintenance of plasma membrane microstructure can be via physical features that provide intrinsic ordering such as lipid microdomains, or from membrane -associated structures such as the cytoskeleton. Recent evidence indicates, that in the case of plant cells , the cell wall seems to be a major player in maintaining plasma membrane microstructure.

Characterisation of cell-wall polysaccharides from mandarin segment membranes. In an attempt to develop a process of enzymatic peeling of mandarin segments suitable for use on an industrial scale, the cell wall fraction of the segment membrane of Satsuma mandarin fruits was extracted to obtain a chelating agent-soluble pectin fraction ChSS , a dilute sodium hydroxide-soluble pectin fraction DASS , a 1M sodium hydroxide-soluble hemicellulose fraction 1MASS , a 4M sodium hydroxide-soluble hemicellulose fraction 4MASS and a cellulose-rich residue 3.

The ChSS pectin consisted mainly of galacturonic acid followed by arabinose and galactose. Eighty-nine percent of the galacturonic acid present in the segment membranes was recovered in the above two pectin fractions. The two hemicellulosic fractions consisted of two different molecular weight populations, which also differed in their sugar composition. Arabinose, xylose, mannose, galactose and glucose were the main sugar constituents of these hemicellulose fractions.

In addition to an arabino xylan and a xyloglucan, the presence of an arabinogalactan is suggested by the sugar composition of both hemicelluloses.

The pectin fractions were also characterised by their degradability by the pectic enzymes polygalacturonase, pectinmethylesterase and rhamnogalacturonan hydrolase. However the degree of degradation of the pectin fractions by enzymes differed, and the amount of the polymeric materials resistant to further degradation and the oligomeric products also differed. Using pectic enzymes it is possible to obtain peeled mandarin segments ready to eat or for canning. Plant cell wall secretion and lipid traffic at membrane contact sites of the cell cortex.

Plant cell wall secretion is the result of dynamic vesicle fusion events at the plasma membrane. The importance of the lipid bilayer environment of the plasma membrane and its interactions with the endomembrane system through vesicle traffic are well recognized. Recent advances in yeast molecular biology and biochemistry lead us to re-examine the hypothesis that non-vesicular traffic of lipids through close contact sites of the plasma membrane and endoplasmic reticulum could also be important in plant cell wall biosynthesis.

Non-vesicular traffic is the extraction and transfer of individual lipid molecules from a donor bilayer to a target bilayer, usually with the assistance of lipid transfer proteins. The connection of cytoskeletal network with plasma membrane and the cell wall. The cell wall provides external support of the plant cells , while the cytoskeletons including the microtubules and the actin filaments constitute an internal framework. The cytoskeletons contribute to the cell wall biosynthesis by spatially and temporarily regulating the transportation and deposition of cell wall components.

This tight control is achieved by the dynamic behavior of the cytoskeletons, but also through the tethering of these structures to the plasma membrane. This tethering may also extend beyond the plasma membrane and impact on the cell wall , possibly in the form of a feedback loop. We also discuss the prospective roles of these components in cell wall biosynthesis and modifications, and aim to provide a platform for further studies in this field.

Vesicles between plasma membrane and cell wall prior to visible senescence of Iris and Dendrobium flowers. Cut Iris flowers Iris x hollandica, cv. Blue Magic show visible senescence about two days after full opening. Epidermal cells of the outer tepals collapse due to programmed cell death PCD. Transmission electron microscopy TEM showed irregular swelling of the cell walls , starting prior to cell collapse. Compared to cells in flowers that had just opened, wall thickness increased up to tenfold prior to cell death.

Fibrils were visible in the swollen walls. After cell death very little of the cell wall remained. Prior to and during visible wall swelling, vesicles paramural bodies were observed between the plasma membrane and the cell walls. The vesicles were also found in groups and were accompanied by amorphous substance. They usually showed a single membrane , and had a variety of diameters and electron densities. Cut Dendrobium hybrid cv.

Lucky Duan flowers exhibited visible senescence about 14 days after full flower opening. Paramural bodies were also found in Dendrobium tepal epidermis and mesophyll cells , related to wall swelling and degradation.

Although alternative explanations are well possible, it is hypothesized that paramural bodies carry enzymes involved in cell wall breakdown. Cell wall polysaccharide biosynthesis by membrane fragments from Streptococcus pyogenes and stabilized L-form. The formation and composition of a cell wall rhamnose-containing polysaccharide by membrane fragments from Streptococcus pyogenes and its stabilized L-form were compared.

Also, the effect of prior treatment on the ability of coccal whole- cell and membrane fragments to incorporate radioactivity from thymidine diphosphate- 14 C-rhamnose, and the results of subsequent attempts to remove labeled polysaccharide from such membranes are given. However, once bound, both membrane fragments polymerized rhamnose to the same extent. These findings tend to negate the almost complete lack of polymeric rhamnose within the intact L-form as being due to the absence of membrane enzymes necessary for the transfer of rhamnose from a suitable precursor to membrane acceptor sites or enzymes responsible for rhamnose polymerization.

Degradation of labeled rhamnose polysaccharide after isolation from coccal membranes by mild acid hydrolysis showed muramic acid and glucosamine to be attached. This same polysaccharide from L-form membrane fragments was devoid of amino sugars. These data suggest the possible involvement of amino sugars in the attachment of cell wall polymeric rhamnose to the streptococcal cytoplasmic membrane. The absence of attached amino sugars to rhamnose polysaccharide from L-form membrane fragments is discussed in terms of this organism's continued inability for new cell wall formation.

The isolation, from streptococcal membrane fragments, of a polysaccharide containing rhamnose and amino sugars common to at least two different streptococcal cell wall -type polymers was demonstrated. S-layer and cytoplasmic membrane - exceptions from the typical archaeal cell wall with a focus on double membranes. The common idea of typical cell wall architecture in archaea consists of a pseudo-crystalline proteinaceous surface layer S-layer , situated upon the cytoplasmic membrane.

This is true for the majority of described archaea, hitherto. Within the crenarchaea, the S-layer often represents the only cell wall component, but there are various exceptions from this wall architecture. Beside glycosylated S-layers in hyper thermophilic cren- and euryarchaea as well as halophilic archaea, one can find a great variety of other cell wall structures like proteoglycan-like S-layers Halobacteria , glutaminylglycan Natronococci , methanochondroitin Methanosarcina or double layered cell walls with pseudomurein Methanothermus and Methanopyrus.

The presence of an outermost cellular membrane in the crenarchaeal species Ignicoccus hospitalis already gave indications for an outer membrane similar to Gram-negative bacteria. Although there is just limited data concerning their biochemistry and ultrastructure, recent studies on the euryarchaeal methanogen Methanomassiliicoccus luminyensis, cells of the ARMAN group, and the SM1 euryarchaeon delivered further examples for this exceptional cell envelope type consisting of two membranes.

S-layer and cytoplasmic membrane — exceptions from the typical archaeal cell wall with a focus on double membranes. Plasma membrane microdomains from hybrid aspen cells are involved in cell wall polysaccharide biosynthesis.

Detergent-resistant plasma membrane microdomains [DRMs detergent-resistant membranes ] were isolated recently from several plant species. As for animal cells , a large range of cellular functions, such as signal transduction, endocytosis and protein trafficking, have been attributed to plant lipid rafts and DRMs. The data available are essentially based on proteomics and more approaches need to be undertaken to elucidate the precise function of individual populations of DRMs in plants.

We report here the first isolation of DRMs from purified plasma membranes of a tree species, the hybrid aspen Populus tremula x tremuloides, and their biochemical characterization. Plasma membranes were solubilized with Triton X and the resulting DRMs were isolated by flotation in sucrose density gradients.

The DRMs were enriched in sterols, sphingolipids and glycosylphosphatidylinositol-anchored proteins and thus exhibited similar properties to DRMs from other species. The association of these enzymes with DRMs was demonstrated using specific glucan synthase assays and antibodies, as well as biochemical and chemical approaches for the characterization of the polysaccharides synthesized in vitro by the isolated DRMs.

In addition to shedding light on the lipid environment of callose and cellulose synthases, our results demonstrate the involvement of DRMs in the biosynthesis of important cell wall polysaccharides. This novel concept suggests a function of plant membrane microdomains in cell growth and morphogenesis.

Fungal cell walls and cell membranes are the main targets of antifungals. In this study, we report on the antifungal activity of an ethanol extract from Paeonia lactiflora against Candida albicans, showing that the antifungal activity is associated with the synergistic actions of preventing cell wall synthesis, enabling membrane depolarization, and compromising permeability.

First, it was shown that the ethanol extract from P. In isotonic media, cell bursts of C. Second, the ethanol extract from P. Membrane depolarization manifested as increased fluorescence intensity by staining P. Membrane permeability was assessed by crystal violet assay, and C.

The findings suggest that P. AT14A mediates the cell wall -plasma membrane -cytoskeleton continuum in Arabidopsis thaliana cells. AT14A has a small domain that has sequence similarities to integrins from animals. Integrins serve as a transmembrane linker between the extracellular matrix and the cytoskeleton, which play critical roles in a variety of biological processes.

Because the function of AT14A is unknown, Arabidopsis thaliana AT14A, which is a transmembrane receptor for cell adhesion molecules and a middle member of the cell wall -plasma membrane -cytoskeleton continuum in plants, has been described. AT14A, co-expressed with green fluorescent protein GFP , was found to localize mainly to the plasma membrane.

The mutant Arabidopsis at14a-1 cells exhibit various phenotypes with cell shape, cell cluster size, thickness, and cellulose content of cell wall , the adhesion between cells , and the adhesion of plasma membrane to cell wall varied by plasmolysis.

Using direct staining of filamentous actin and indirect immunofluorescence staining of microtubules, cortical actin filaments and microtubules arrays were significantly altered in cells , either where AT14A was absent or over-expressed. It is concluded that AT14A may be a substantial middle member of the cell wall -plasma membrane -cytoskeleton continuum and play an important role in the continuum by regulating cell wall and cortical cytoskeleton organization.

These sensory cells use a membrane protein, Slc26a5 prestin , to generate mechanical force at high frequencies, which is essential for explaining the exquisite hearing sensitivity of mammalian ears. Previous studies suggest that Slc26a5 continuously diffuses within the membrane , but how can a freely moving motor protein effectively convey forces critical for hearing? These mice and four other strains expressing fluorescently labeled membrane proteins were used to examine their lateral diffusion in the OHC lateral wall.

All five proteins showed minimal diffusion, but did move after pharmacological disruption of membrane -associated structures with a cholesterol-depleting agent and salicylate. The structural constraint of membrane proteins may exemplify convergent evolution of cellular motors across species. Our findings also suggest a possible mechanism for disorders of cholesterol metabolism with hearing loss such as Niemann-Pick Type C diseases.

Mechanics of membrane bulging during cell-wall disruption in Gram-negative bacteria. The bacterial cell wall is a network of sugar strands crosslinked by peptides that serve as the primary structure for bearing osmotic stress. Despite its importance in cellular survival, the robustness of the cell wall to network defects has been relatively unexplored.

Treatment of the Gram-negative bacterium Escherichia coli with the antibiotic vancomycin, which disrupts the crosslinking of new material during growth, leads to the development of pronounced bulges and eventually of cell lysis.

Here, we model the mechanics of the bulging of the cytoplasmic membrane through pores in the cell wall. This critical pore size is large compared to the typical distance between neighboring peptides and glycan strands, and hence pore size acts as a constraint on network integrity.

We also discuss the general implications of our model to membrane deformations in eukaryotic blebbing and vesiculation in red blood cells. Endocytic pathways involved in PLGA nanoparticle uptake by grapevine cells and role of cell wall and membrane in size selection.

Clathrin-independent endocytosis is the main internalization route. The cell wall plays a more prominent role than the plasma membrane in NPs' size selection. In the last years, many studies on absorption and cell uptake of nanoparticles by plants have been conducted, but the understanding of the internalization mechanisms is still largely unknown. In this study, polydispersed and monodispersed poly lactic-co-glycolic acid nanoparticles PLGA NPs were synthesized, and a strategy combining the use of transmission electron microscopy TEM , confocal analysis, fluorescently labeled PLGA NPs, a probe for endocytic vesicles FM , and endocytosis inhibitors i.

A strong adhesion of PLGA NPs to the outer side of the cell wall was observed, presumably due to electrostatic interactions. Confocal microscopy and treatment with endocytosis inhibitors suggested the involvement of both clathrin-dependent and clathrin-independent endocytosis in cell uptake of PLGA NPs and the latter appeared to be the main internalization pathway. Experiments on grapevine protoplasts revealed that the cell wall plays a more prominent role than the plasma membrane in size selection of PLGA NPs.

Cell wall and membrane changes associated with ethambutol resistance in Mycobacterium tuberculosis H37Ra. Biochemical variations accompanying the acquisition of ethambutol EMB resistance in a single-step mutant of Mycobacterium tuberculosis H37Ra were analyzed.

Comparative analysis of phospholipids revealed a reduced content in the EMB-resistant strain, particularly in the cell membrane fraction. Significant alterations were observed in the individual phospholipid content and phospholipid fatty acyl group composition of whole cells and subcellular fractions. Quantitative changes were seen in the chemical constituents of the cell walls of resistant cultures in comparison with those of EMB-susceptible cultures of M. Alterations in the binding of 1-anilinonaphthalenesulfonate to whole cells of an EMB-resistant strain indicated structural changes on the cell surface.

Structural changes in the cell wall may play an important role in the resistance of M. Gravity resistance, another graviresponse in plants - role of microtubule- membrane-cell wall continuum. Resistance to the gravitational force has been a serious problem for plants to survive on land, after they first went ashore more than million years ago. Thus, gravity resistance is the principal graviresponse in plants comparable to gravitropism.

Nevertheless, only limited information has been obtained for this second gravity response. We have examined the mechanism of gravity resistance using hypergravity conditions produced by centrifugation. The results led a hypothesis on the mechanism of plant resistance to the gravitational force that the plant constructs a tough body by increasing the cell wall rigidity, which are brought about by modification of the cell wall metabolism and cell wall environment, especially pH.

On the other hand, we have shown that gravity signal may be perceived by mechanoreceptors mechanosensitive ion channels on the plasma membrane and amyloplast sedimentation in statocytes is not involved in gravity resistance.

Moreover, hypergravity treatment increased the expression levels of genes encoding alpha-tubulin, a component of microtubules and 3-hydroxymethylglutaryl-Coenzyme A reductase HMGR , which catalyzes a reaction producing mevalonic acid, a key precursor of terpenoids such as membrane sterols. The expression of HMGR and alpha- and beta-tubulin genes increased within several hours after hypergravity treatment, depending on the magnitude of gravity.

The determination of levels of gene products as well as the analysis with knockout mutants of these genes by T-DNA insertions in Arabidopsis supports the involvement of both membrane sterols and microtubules in gravity resistance. These results suggest that structural or physiological continuum of microtubule- cell membrane-cell wall is responsible for plant resistance to the gravitational force.

Single wall carbon nanotubes enter cells by endocytosis and not membrane penetration. Background Carbon nanotubes are increasingly being tested for use in cellular applications. Determining the mode of entry is essential to control and regulate specific interactions with cells , to understand toxicological effects of nanotubes, and to develop nanotube-based cellular technologies.

These data suggest energy-dependent endocytosis, as shown previously. We also examined the possibility for non-specific physical penetration of SWCNTs through the plasma membrane. Electrochemical impedance spectroscopy and Langmuir monolayer film balance measurements showed that Pluronic-stabilized SWCNTs associated with membranes but did not possess sufficient insertion energy to penetrate through the membrane.

SWCNTs associated with vesicles made from plasma membranes but did not rupture the vesicles. A novel membrane anchor for FtsZ is linked to cell wall hydrolysis in Caulobacter crescentus. In most bacteria, the tubulin-like GTPase FtsZ forms an annulus at midcell the Z-ring which recruits the division machinery and regulates cell wall remodeling. Although both activities require membrane attachment of FtsZ, few membrane anchors have been characterized. FtsA is considered to be the primary membrane tether for FtsZ in bacteria, however in Caulobacter crescentus, FtsA arrives at midcell after stable Z-ring assembly and early FtsZ-directed cell wall synthesis.

We hypothesized that additional proteins tether FtsZ to the membrane and demonstrate that in C. FzlC associates with membranes directly in vivo and in vitro and recruits FtsZ to membranes in vitro.

As for most known membrane anchors, the C-terminal peptide of FtsZ is required for its recruitment to membranes by FzlC in vitro and midcell recruitment of FzlC in cells. In vivo, overproduction of FzlC causes cytokinesis defects whereas deletion of fzlC causes synthetic defects with dipM, ftsE and amiC mutants, implicating FzlC in cell wall hydrolysis. Our characterization of FzlC as a novel membrane anchor for FtsZ expands our understanding of FtsZ regulators and establishes a role for membrane -anchored FtsZ in the regulation of cell wall hydrolysis.

Northern gel-blot analysis revealed what appeared to be a single transcript, but three distinct polypeptides were detected in immunogel-blot analyses of the ExGases extracted from growing coleoptiles. Two polypeptides appear in the cell wall , where one polypeptide is constitutive, and the second appears at the time of the maximum rate of elongation and reaches peak activity after elongation has ceased.

The third polypeptide of the ExGase is an extrinsic protein associated with the exterior surface of the plasma membrane. We propose three potential functions for this novel ExGase at the membrane-wall interface. Multi- walled carbon nanotubes affect drug transport across cell membrane in rat astrocytes. The impact of carbon nanotubes on the cell membrane is an aspect of particular importance and interest in the study of carbon nanotubes' interactions with living systems.

One of the many functions of the cell membrane is to execute substance transport into and out of the cell. We investigated the influence of multi- walled carbon nanotubes MWCNTs on the transport of several compounds across in the cell membrane of rat astrocytes using flow cytometry. Results showed that MWCNTs significantly inhibited cellular uptake of doxorubicin but not the other drugs and the mode of loading made a significant difference in doxorubicin uptake.

Retention of fluorescein, carboxyfluorescein and rhodamine was remarkably higher in MWCNT-exposed cells after an efflux period. A kinetics study also demonstrated slower efflux of intracellular fluorescein and rhodamine The implications of the findings are discussed. The mechanism of the initial steps of bacteriophage infection in Lactococcus lactis subsp. All seven phages adsorbed to the same sites on the host cell wall that are composed, in part, of rhamnose. This was suggested by rhamnose inhibition of phage adsorption to cells , competition between phage c2 and the other phages for adsorption to cells , and rhamnose inhibition of lysis of phage-inoculated cultures.

The adsorption to the cell wall was found to be reversible upon dilution of the cell wall -adsorbed phage. In a reaction step that apparently follows adsorption to the cell wall , all seven phages adsorbed to a host membrane protein named PIP.

This was indicated by the inability of all seven phages to infect a strain selected for resistance to phage c2 and known to have a defective PIP protein. All seven phages were inactivated in vitro by membranes from wild-type cells but not by membranes from the PIP-defective, phage c2-resistant strain. The mechanism of membrane inactivation was an irreversible adsorption of the phage to PIP, as indicated by adsorption of [35S] methionine-labeled phage c2 to purified membranes from phage-sensitive cells but not to membranes from the resistant strain, elimination of adsorption by pretreatment of the membranes with proteinase K, and lack of dissociation of 35S from the membranes upon dilution.

These results suggest that many lactococcal phages adsorb initially to the cell wall and subsequently to host cell membrane protein PIP, which leads to ejection of the phage genome.

Treatment of the carrot cells with the cell wall digestion enzymes, driselase, in a sorbitol osmoticum for 1. Driselase treatment resulted in decreased phosphorylation of a band of Mr 80, which showed almost complete calcium dependence in the osmoticum treated cells ; decreased phosphorylation of a band of Mr 15, which showed little calcium activation, and appearance of a new band of calcium-dependent phosphorylation at Mr 22, These effects appeared not to be due to nonspecific protease activity and neither in vivo nor in vitro exposure to driselase caused a significant loss of Coomassie blue-staining bands on the gels of the isolated plasma membranes.

However, protein phosphorylation was decreased. Adding driselase to the in vitro reaction mixture caused a general decrease in the membrane protein phosphorylation either in the presence or absence of calcium which did not mimic the in vivo response.

Cells labeled in vivo with inorganic 32P also showed a response to the Driselase treatment. An enzymically active driselase preparation was required for the observed responses. Plasma membrane vesicles from wild carrot cells grown in suspension culture were isolated by aqueous two-phase partitioning, and ATP-dependent phosphorylation was measured with [gamma- 32 P]ATP in the presence and absence of calcium.

Driselase treatment resulted in decreased phosphorylation of a band of M r 80, which showed almost complete calcium dependence in the osmoticum treated cells ; decreased phosphorylation of a band of M r 15, which showed little calcium activation, and appearance of a new band of calcium-dependent phosphorylation at M r 22, Cells labeled in vivo with inorganic 32 P also showed a response to the Driselase treatment.

Cell wall polysaccharide synthases are located in detergent-resistant membrane microdomains in oomycetes. The pathways responsible for cell wall polysaccharide biosynthesis are vital in eukaryotic microorganisms. The corresponding synthases are potential targets of inhibitors such as fungicides.

Despite their fundamental and economical importance, most polysaccharide synthases are not well characterized, and their molecular mechanisms are poorly understood. Interestingly, no cellulose synthase activity was detected in the DRMs.

The purified DRMs exhibited similar biochemical features as lipid rafts from animal, plant, and yeast cells , although they contained some species-specific lipids. The results presented here are consistent with a function of lipid rafts in cell polarization and as platforms for sorting specific sets of proteins targeted to the plasma membrane , such as carbohydrate synthases.

The involvement of DRMs in the biosynthesis of major cell wall polysaccharides in eukaryotic microorganisms suggests a function of lipid rafts in hyphal morphogenesis and tip growth. The lantibiotic NAI binds to bactoprenol-bound cell wall precursors and impairs membrane functions. The lantibiotic NAI is active against Gram-positive bacteria including vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus. To identify the molecular basis of its potency, we studied the mode of action in a series of whole cell and in vitro assays and analyzed structural features by nuclear magnetic resonance NMR.

The lantibiotic efficiently interfered with late stages of cell wall biosynthesis and induced accumulation of the soluble peptidoglycan precursor UDP-N-acetylmuramic acid-pentapeptide UDP-MurNAc-pentapeptide in the cytoplasm. Using membrane preparations and a complete cascade of purified, recombinant late stage peptidoglycan biosynthetic enzymes MraY, MurG, FemX, PBP2 and their respective purified substrates, we showed that NAI forms complexes with bactoprenol-pyrophosphate-coupled precursors of the bacterial cell wall.

Titration experiments indicate that first a 1: Furthermore, lipid II and related molecules obviously could not serve as anchor molecules for the formation of defined and stable nisin-like pores, however, slow membrane depolarization was observed after NAI treatment, which could contribute to killing of the bacterial cell.

Rapid changes in plasma membrane protein phosphorylation during initiation of cell wall digestion. An enzymically active driselas preparation was required for the observed responses. Identification of FtsW as a transporter of lipid-linked cell wall precursors across the membrane. Bacterial cell growth necessitates synthesis of peptidoglycan. Assembly of this major constituent of the bacterial cell wall is a multistep process starting in the cytoplasm and ending in the exterior cell surface.

The intracellular part of the pathway results in the production of the membrane -anchored cell wall precursor, Lipid II. After synthesis this lipid intermediate is translocated across the cell membrane. The translocation flipping step of Lipid II was demonstrated to require a specific protein flippase.

Here, we show that the integral membrane protein FtsW, an essential protein of the bacterial division machinery, is a transporter of the lipid-linked peptidoglycan precursors across the cytoplasmic membrane. This study provides the first biochemical evidence for the involvement of an essential protein in the transport of lipid-linked cell wall precursors across biogenic membranes. Phenyl aldehyde and propanoids exert multiple sites of action towards cell membrane and cell wall targeting ergosterol in Candida albicans.

In the present study, two phyto-compounds phenyl aldehyde cinnamaldehyde and propanoid eugenol were selected to explore their modes of action against Candida albicans. Electron microscopy, flow cytometry and spectroscopic assays were employed to determine the targets of these compounds. Treatment of Candida cells by cinnamaldehyde and eugenol at 0. The binding assays reflected the ability of compounds to bind with the ergosterol. Our findings have suggested that the membrane damaging effects of phenyl aldehyde and propanoids class of compounds is attributed to their ability to inhibit ergosterol biosynthesis and simultaneously binding with ergosterol.

Indirect or secondary action of these compounds on cell wall is also expected as revealed by electron microscopic studies. The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S.

The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. Septins and actin were mislocalized, and cell wall synthesis was very abnormal, including long projections of cell wall into the cytoplasm. These results expand the roles of eisosomes by demonstrating that Sur7 is needed for proper plasma membrane organization and cell wall synthesis.

A conserved Cys motif in the first extracellular loop of fungal Sur7 proteins is similar to a characteristic motif of the claudin proteins that form tight junctions in animal cells , suggesting a common role for these tetraspanning membrane proteins in forming specialized plasma membrane domains. Plasma membrane-cell wall connections: Tradescantia virginiana leaf epidermal cells were plasmolysed by sequential treatment with 0.

Plasmolysis revealed adhesion of the plasma membrane to the cell wall at sites coinciding with cytoskeletal arrays involved in the polarisation of cells undergoing asymmetric divisions--cortical actin patch--and in the establishment and maintenance of the division site--preprophase band of microtubules and filamentous F actin.

The majority of cells retained adhesions at the actin patch throughout mitosis. After the breakdown of the nuclear envelope, plasmolysis had a dramatic effect on spindle orientation, cell plate formation, and the plane of cytokinesis. Spindles were rotated at abnormal angles including tilted into the plane of the epidermis.

Cell plates formed but were quickly replaced by vacuole-like intercellular compartments containing no Tinopal-stainable cell wall material. This compartment usually opened to the apoplast at one side, and cytokinesis was completed by the furrow extending across the protoplast. This atypical cytokinesis was facilitated by a phragmoplast containing microtubules and F-actin. Progression of the furrow was unaffected by 25 micrograms of cytochalasin B per ml but inhibited by 10 microM oryzalin.

Phragmoplasts were contorted and misguided and cytokinesis prolonged, indicating severe disruption to the guidance mechanisms controlling phragmoplast expansion. The mechanism of human T-lymphocyte activation by the pathogenic yeast Cryptococcus neoformans has not been established.

Previous investigations have suggested that C. Because of the potential importance of the mechanism of T- cell activation for our understanding of the immune response to C. The T- cell response to C. However, allogeneic cells were sufficient for accessory cell function, indicating that the response was not major histocompatibility complex restricted. The percentage of T cells in the cell cycle was higher than that with the recall antigen tetanus toxoid but lower than that with the mitogenic lectin phytohemagglutinin A or the superantigen Staphylococcus enterotoxin B.

Compared to the case for most mitogens or superantigens, the proliferative response is late and the number of T cells that enter the cell cycle and the precursor frequency are low, indicating that the mitogenic effect is modest.

However, the mitogenic effect of C. Crystal structure of MraY, an essential membrane enzyme for bacterial cell wall synthesis. MraY phospho-MurNAc-pentapeptide translocase is an integral membrane enzyme that catalyzes an essential step of bacterial cell wall biosynthesis: MraY has long been considered a promising target for the development of antibiotics, but the lack of a structure has hindered mechanistic understanding of this critical enzyme and the enzyme superfamily in general.

Single- wall carbon nanotube-based proton exchange membrane assembly for hydrogen fuel cells. A membrane electrode assembly MEA for hydrogen fuel cells has been fabricated using single- walled carbon nanotubes SWCNTs support and platinum catalyst. Scanning electron microscopy and Raman spectroscopy showed that the nanotubes and the platinum retained their nanostructure morphology on the carbon fiber surface.

Electrochemical impedance spectroscopy EIS revealed that the carbon nanotube-based electrodes exhibited an order of magnitude lower charge-transfer reaction resistance R ct for the hydrogen evolution reaction HER than did the commercial carbon black CB -based electrodes. Relative contribution of the cell wall , cytoplasmic membrane , and cytoplasm to the gram-positive characteristic of Bacillus megaterium.

Full Text Available The effect on Ambrosia artemisiifolia common ragweed of combining cutting and herbicide application was studied in pot experiments in Germany and Denmark in Matrigon, mesotrione in Germany and Denmark: Callisto and glyphosate in Germany: Roundup Bio were applied at 4 doses at three different timings: The plants were harvested 5 weeks after the last herbicide application.

At both sites clopyralid and mesotrione had a low efficacy on common ragweed when applied on developed plants with only minor differences in efficacy at the three timings. Application after cutting improved the efficacy of clopyralid at both sites and of mesotrione in Denmark. In Germany glyphosate had a higher efficacy on noncut plants in comparison to the cut plants, in Denmark it was vice versa.

The highest dose of glyphosate provided higher control levels on developed plants than clopyralid and mesotrione at both sites. In Denmark the highest effects were obtained shortly after cutting with the maximum dose of each herbicide and declined with time between cutting and herbicide application.

In summary the results demonstrated that herbicides can be applied shortly after cutting without loss of efficacy. Agricultural fields under integrated pest management and ecological farming were monitored The aim was to assess the performance of chemical and other control measures against ragweed under farming conditions of the region. These parameters were ranked and, by way of multiplication, merged into one single value, which can be expressed as degree of a defined intense infestation level.

Such approach is considered to be useful to track recuperation efforts and estimate control efficiency by comparing pre and post measure infestation status. The index is applied to results of the growing season, which is illustrated by some examples. Molecular and immunological characterization of ragweed Ambrosia artemisiifolia L.

Full Text Available Climate change and air pollution, including ozone is known to affect plants and might also influence the ragweed pollen, known to carry strong allergens. We compared the transcriptome of ragweed pollen produced under ambient and elevated ozone by sequencing. Pollen surface was examined by scanning electron microscopy and attenuated total reflectance-Fourier transform infrared spectroscopy ATR-FTIR, and phenolics were analysed by high-performance liquid chromatography.

Elevated ozone had no influence on the pollen size, shape, surface structure or amount of phenolics. Transcriptomic analyses showed changes in expressed-sequence tags ESTs, including allergens. The data highlight a direct influence of ozone on the exine components and transcript level of allergens.

As the total protein amount of Amb a 1 was not altered, a direct correlation to an increased risk to human health could not be derived.

Additional, the sequencing contributes to the identification of stress-related transcripts in mature pollen that could be grouped into distinct gene ontology terms. Climate change and air pollution, including ozone is known to affect plants and might also influence the ragweed pollen, known to carry strong allergens. Pollen surface was examined by scanning electron microscopy and attenuated total reflectance-Fourier transform infrared spectroscopy ATR-FTIR , and phenolics were analysed by high-performance liquid chromatography.

Transcriptomic analyses showed changes in expressed-sequence tags ESTs , including allergens. New Sesquiterpenoids from Ambrosia artemisiifolia L. Full Text Available A new pseudoguaianolide 1 and two new guaiane-type sesquiterpene glucosides 2 and 3, were isolated from the aerial parts of Ambrosia artemisiifolia L together with two known sesquiterpene dilactones 4 and 5. The isolated compounds were evaluated for cytotoxicity against human promyelocytic leukemia HL cell lines in vitro, but were all inactive.

Results showed that increasing density of A. There was no significant impact on peanut plant height. Exponential regression model was the best in describing the relationship between A. Immunoproteomic characterization of Ambrosia artemisiifolia pollen allergens in canine atopic dermatitis. Short ragweed Ambrosia artemisiifolia pollen represents one of the major seasonal sources of allergenic pollen proteins in Europe, particularly in the Pannonian valley of the Balkan region. Therefore, characterization of Ambrosia artemisiifolia pollen components, in terms of defining major and minor allergens that induce clinically manifested allergic reaction in dogs, is important for valid diagnosis and efficient therapy.

This study has, for the first time, characterized and identified major Ambrosia artemisiifolia allergens in CAD, using an immunoproteomic approach. To assess the prevalence of specific IgE in electrophoretically separated ragweed pollen proteins, individual reactivity of sera from dogs with CAD was analyzed and compared to the reactivity of sera from healthy dogs in the non-reducing conditions, which were found optimal for specific canine IgE detection.

The most prominent ragweed proteins in CAD, represent, as in humans, variants of all five isoallergens of the Amb a 1 group pectate lyase: Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. New sets of genomic and expressed sequence tag EST based simple sequence repeats SSRs markers were developed in this species using three approaches.

After validation, 13 genomic SSRs and 13 EST-SSRs were retained and used to characterize the genetic diversity and population genetic structure of Ambrosia artemisiifolia populations from the native North America and invasive Europe ranges of the species. Analysing the mating system based on maternal families did not reveal any departure from complete allogamy and excess homozygosity was mostly due the presence of null alleles. High genetic diversity and patterns of genetic structure in Europe suggest two main introduction events followed by secondary colonization events.

Cross-species transferability of the newly developed markers to other invasive species of the Ambrosia genus was assessed. Cloning, expression, and characterization of pollen allergens from Humulus scandens Lour Merr and Ambrosia artemisiifolia L. The allergen genes were selectively amplified in the weed pollen cDNA pool by using a special PCR profile, with the primers designed by a modeling procedure.

Following truncated gene cloning and confirmation of the pollen source, unknown 3'cDNA ends were identified by using the 3'-RACE method. The gene function conferred by the full-length coding region was evaluated by a homologue search in the GenBank database. Recombinant proteins expressed in Escherichia coli pET RosettaBlue cells were subsequently characterized by N-terminal end sequencing, IgE binding, and crossreactivity.

Three full-length cDNAs were obtained in each weed. Five recombinant proteins were abundantly expressed in nonfusion forms and were confirmed by using the N-terminal end sequence identity. Sera from patients who were allergic to A artemisiifolia reacted not only with rAmb a 8 D03 derived from A artemisiifolia , but also with recombinant protein rHum s 1 LCM9 derived from H scandens, which confirmed the allergenicity and cross-reactivity of the recombinant proteins from the 2 sources.

Comparison of the degenerate primers used for truncated gene cloning with the full-length cDNA demonstrated that alternative nucleotide degeneracy occurred.

This study demonstrates a useful method for cloning homologous allergen genes across different species, particularly for little-studied species. The weeding of Ambrosia artemisiifolia and sanitary risks. Ambrosia artemisiifolia is a potentially allergenic annual herbaceous plant coming from North America and widespread in Italy, where it can be easily seen since May-April. Its pollination is mainly windborne and each plant is able to produce billions of pollen grains.

The pollen peaks are in the hottest days in the absence of rain and wind. In susceptible individuals, the great amount of pollen produced by this species may cause rhinitis and severe asthma attacks. Some allergic subjects can manifest disorders already at a concentration of a few granules per cubic metre. Chemical control is often practiced on a large scale and uses herbicides.

A major risk is the result of the unprofessional use of chemicals by the population, especially in residential or very busy areas eg railways, urban areas. In this paper we propose preventive measures of chemical hazards that may be resulting from the excessive use of plant protection products.

Its pollen can be transported over large distances and has been recognized as a significant cause of hayfever and asthma D'Amato et al. RegCM4 was adapted to incorporate the pollen emissions from ORCHIDEE French Global Land Surface Model and a pollen tracer model for describing pollen convective transport, turbulent mixing, dry and wet deposition over extensive domains, using consistent assumption regarding the transport of multiple species Fabien et al. We performed two families of recent-past simulations on the Euro-Cordex domain simulation for future condition is been considering.

The observations were divided into two groups and used for calibration and validation separately. A wide range of possible calibration coefficients were tested for each calibration station, making the bias between observations and simulations within an admissible value then.

Gradual loss of genetic diversity of Ambrosia artemisiifolia L. Over the last two decades, while expanding toward southern parts of Serbia, this common ragweed has become a very troublesome plant species in the whole country. Considering the importance of genetic studies in understanding of invasive species, our main objectives in this study were to analyze the genetic diversity and genetic structure of Ambrosia artemisiifolia populations from Central Serbia, a relatively recently invaded region.

Comparing values of genetic measures obtained by microsatellite analyses, a number of differences were detected in genetic diversity between sampled populations. Allelic richness-r ranged from 5. We observed greater genetic variability in populations from the northern part of investigated area than in southern populations. Data obtained for analyses of differentiation and gradual losses of genetic diversity of sampled populations provides useful information about invasion dynamics of common ragweed in recently invaded region.

Changes in defense of an alien plant Ambrosia artemisiifolia before and after the invasion of a native specialist enemy Ophraella communa. Full Text Available The evolution of increased competitive ability hypothesis EICA predicts that when alien plants are free from their natural enemies they evolve lower allocation to defense in order to achieve a higher growth rate. If this hypothesis is true, the converse implication would be that the defense against herbivory could be restored if a natural enemy also becomes present in the introduced range.

We tested this scenario in the case of Ambrosia artemisiifolia common ragweed - a species that invaded Japan from North America. We collected seeds from five North American populations, three populations in enemy free areas of Japan and four populations in Japan where the specialist herbivore Ophraella communa naturalized recently. Using plants grown in a common garden in Japan, we compared performance of O.

Conversely, in locations where the herbivore O. These results strengthen the case for EICA and suggest that defense levels of alien populations can be recuperated rapidly after the native specialist becomes present in the introduced range. Our study implies that the plant defense is evolutionary labile depending on plant-herbivore interactions. Northern range edge equilibrium of Ambrosia artemisiifolia L.

Full Text Available Description of the subject. The geographic distributions of a species, be it native or alien, is expected to be limited at some point by environmental conditions. In this situation, a range edge equilibrium REE takes place, i. The occurrence of REE has never been tested for an invasive species. In Western Europe, the invasive weed Ambrosia artemisiifolia L. It is currently unknown whether the range has reached a limit or not. Information about how the species responds to sunflower competition is also lacking.

This work addressed two questions: Has the northern part of A. Plots were established in an agricultural field ca. The following year, the population growth rates and the soil seed bank were assessed. The species established populations with relatively high growth rates and soil seed bank.

Sunflower competition did not have a significant impact on plant performance. The results invalidate the hypothesis of equilibrium at the current margin of A.

Let native species take their course: Ambrosia artemisiifolia replacement during natural or ;artificial; succession. In this study, we considered the time-span in which the species is suppressed during active restoration actions and passive spontaneous vegetation recovery. In particular, we envisaged that A. Three different treatments were applied within an abandoned quarry area commonly invaded by A. We determined the effect of mixtures of grassland species, established from native hayseed or from a commercial seed mixture, on A.

The results demonstrated that, after the first growing season, compared with spontaneous succession, both commercial seed and hayseed resulted in a strong reduction of A.

After the second growing season, A. This study indicated that both active and passive vegetation recovery by niche filling and competitive exclusion could be used as methods individually or in combination with other methods, such as mowing and biological control, to suppress A. Scientific Opinion on the effect on public or animal health or on the environment on the presence of seeds of Ambrosia spp. The genus Ambrosia Asteraceae family is distributed worldwide.

Ambrosia artemisiifolia common ragweed has heavily colonised several areas of South-East Europe. Life history trait differentiation and local adaptation in invasive populations of Ambrosia artemisiifolia in China.

Local adaptation has been suggested to play an important role in range expansion, particularly among invasive species. However, the extent to which local adaptation affects the success of an invasive species and the factors that contribute to local adaptation are still unclear. This study aimed to investigate a case of population divergence that may have contributed to the local adaptation of invasive populations of Ambrosia artemisiifolia in China.

Common garden experiments in seven populations indicated clinal variations along latitudinal gradients, with plants from higher latitudes exhibiting earlier flowering and smaller sizes at flowering. In reciprocal transplant experiments, plants of a northern Beijing origin produced more seeds at their home site than plants of a southern Wuhan origin, and the Wuhan-origin plants had grown taller at flowering than the Beijing-origin plants in Wuhan, which is believed to facilitate pollen dispersal.

These results suggest that plants of Beijing origin may be locally adapted through female fitness and plants from Wuhan possibly locally adapted through male fitness. Selection and path analysis suggested that the phenological and growth traits of both populations have been influenced by natural selection and that flowering time has played an important role through its direct and indirect effects on the relative fitness of each individual.

This study evidences the life history trait differentiation and local adaptation during range expansion of invasive A. New insights into ragweed pollen allergens. Pollen allergens from short ragweed Ambrosia artemisiifolia cause severe respiratory allergies in North America and Europe. To date, ten short ragweed pollen allergens belonging to eight protein families, including the recently discovered novel major allergen Amb a 11, have been recorded in the International Union of Immunological Societies IUIS allergen database.

With evidence that other components may further contribute to short ragweed pollen allergenicity, a better understanding of the allergen repertoire is a requisite for the design of proper diagnostic tools and efficient immunotherapies. This review provides an update on both known as well as novel candidate allergens from short ragweed pollen, identified through a comprehensive characterization of the ragweed pollen transcriptome and proteome. Common ragweed invasion in Sweden: Common ragweed Ambrosia artemisiifolia is a neophyte from North America that has spread rapidly throughout Europe.

Because the pollen of common ragweed is highly allergic, many countries have adopted containment and mitigation measures. The neophyte has only recently established flowering populations in Sweden. We use this well documented case to study the early impacts of an invasive species on human health. Our identification strategy relies on spatial and temporal variation in common rag Full Text Available Germination characteristics and frost tolerance of seedlings are crucial parameters for establishment and invasion success of plants.

Within this study, we investigated germination characteristics of Ambrosia artemisiifolia L. We determined germination rates and speed under different temperature conditions. From these parameters we calculated minimal, optimal, and maximal temperature for germination. We also investigated the frost tolerance of seedlings. The European populations were characterized by a higher fitness with higher germination rates and germination speed, increased biomass and higher frost tolerance of seedlings.

Furthermore, the temperature niche width for germination was significantly broader for the European populations. The increased frost tolerance of the European populations might allow germination earlier in the year which may subsequently lead to higher biomass allocation — due to a longer growing period — and result in higher pollen and seed production.

The increase in germination rates, germination speed and seedling frost tolerance might result in a higher fitness of the European populations which may facilitate further successful invasion and sharpen the existing problems. Effects of seed traits variation on seedling performance of the invasive weed, Ambrosia artemisiifolia L. Seedling performance can determine the survival of a juvenile plant and impact adult plant performance.

Understanding the factors that may impact seedling performance is thus critical, especially for annuals, opportunists or invasive plant species. Seedling performance can vary among mothers or populations in response to environmental conditions or under the influence of seed traits. However, very few studies have investigated seed traits variations and their consequences on seedling performance.

Specifically, the following questions have been addressed by this work: With seeds from nine Western Europe ruderal populations, seed traits that can influence seedling development were measured. The seeds were sown into growth chambers with warmer or colder temperature treatments.

During seedling growth, performance-related traits were measured. A high variability in seed traits was highlighted. Variation was determined by the mother identity and population, but not latitude. Together, the temperature, population and the identity of the mother had an effect on seedling performance. Seed traits had a relative impact on seedling performance, but this did not appear to be temperature dependent. Seedling performance exhibited a strong plastic response to the temperature, was shaped by the identity of the mother and the population, and was influenced by a number of seed traits.

Prevalence of sensitization to weed pollens of Humulus scandens,Artemisia vulgaris, and Ambrosia artemisiifolia in northern China. Weed pollens are common sources of allergens worldwide. The prevalence of weed pollen sensitization is not yet fully known in China. The purpose of this study was to investigate the prevalence of sensitization to weed allergens from Artemisia, Ambrosia ,and Humulus in northern China.

A total of subjects aged from 5 to 68 years visiting our clinic from June to October underwent intradermal testing using a panel of 25 allergen sources. Subjects with positive skin responses to any pollen were further tested for their serum concentrations of IgE antibodies against Artemisia vulgaris, Ambrosia artemisiifolia ,and Humulus scandens,and against the purified allergens,Art v 1 and Amb a 1.

Of 1 subjects, had positive intradermal reactions to pollen and donated serum for IgE testing. The prevalence of positive intradermal responses to pollens of Artemisia sieversiana,Artemisia annua,A. Among the intradermal positive subjects,the prevalence of specific IgE antigens to A. The prevalence of specific IgE antigens to the allergen Art v 1 was The correlation between the presence of IgE antibodies specific to A.

There were no correlations between the presence of IgE antibodies to H. The intradermal prevalence of weed pollen sensitization among allergic subjects in northern China is about Correlations of specific IgE antibodies suggest that pollen allergens from Artemisia and Humulus are independent sources for primary sensitization.

Mesoscale atmospheric transport of ragweed pollen allergens from infected to uninfected areas. Allergenic ragweed Ambrosia spp. However, the action of air temperature, humidity and solar radiation on pollen grains in the atmosphere could impact on the ability of long distance transported LDT pollen to maintain allergenic potency. Here, we report that the major allergen of Ambrosia artemisiifolia pollen Amb a 1 collected in ambient air during episodes of LDT still have immunoreactive properties.

The amount of Amb a 1 found in LDT ragweed pollen grains was not constant and varied between episodes. In addition to allergens in pollen sized particles, we detected reactive Amb a 1 in subpollen sized respirable particles. These findings suggest that ragweed pollen grains have the potential to cause allergic reactions, not only in the heavily infested areas but, due to LDT episodes, also in the regions unaffected by ragweed populations.

Glyphosate resistance in common ragweed Ambrosia artemisiifolia L. Glyphosate is one of the most commonly used broad-spectrum herbicides over the last 40 years. Due to widespread adoption of glyphosate-resistant GR crop technology, especially, corn, cotton, and soybean, several weed species in agronomic situations have developed resistance to this herbicide. Glyphosate resistance in giant ragweed Ambrosia trifida L. A giant ragweed population from a glyphosate-resistant GR soybean field in Mississippi was suspected to be resistant to glyphosate.

Greenhouse and laboratory studies were conducted to confirm and quantify the magnitude of glyphosate resistance in the giant ragweed population and to elucidate the p Full Text Available Only a limited spectrum of active substances is available for weed control in leguminous plants and sunflowers.

Since the official plant protection service in Brandenburg conducts herbicide field trials in these crop species in the region around Drebkau for the investigation of practicable approaches for control of Ambrosia artemisiifolia. For the cultivation of lupins only pre-emergence herbicides are registered.

Due to the high density of A. Likewise, the performance of authorised herbicides in sunflowers is insufficient. In the region concerned cultivation of grain legumes and sunflowers is limited in areas with high coverage rate of A. Full Text Available Since the beginning of common ragweed registration in North Rhine-Westphalia in there have been ragweed records, among them 31 populations with more than individuals.

Common ragweed is not yet established in North Rhine-Westphalia but seems to do very well on sandy soils in the Lowland. North Rhine-Westphalia is tackling common ragweed in an early stage of invasion and will continue the strategy of rapid response to achieve a total eradication.

Thirty-three countries have already signed the Memorandum of Understanding and over researchers with specialists in weed research, invasive alien species management, ecology, aerobiology, allergology and economics are registered participants of SMARTER. COST Actions interlink nationally funded research projects and enable and finance conferences, working groups, training schools and research exchanges. SMARTER aims to initiate and develop long-term and sustainable control methods, to integrate these into existing mechanical and chemical control measures, and to quantify the success of these measures both for agriculture and health.

The focus is on biological control methods with insects and fungi especially using alien species from the area of origin of Ambrosia and vegetation management to achieve a competitive plant cover. For this, we develop and parameterize models, starting from the population dynamics of Ambrosia , on the impact of control measures on the frequency and distribution of Ambrosia and finally on pollen counts and allergy occurrences, each with both ecological and economic components.

The necessary data are derived from the many experiments that we carry out in well-coordinated studies across Europe. SMARTER will allow the various stakeholders to select optimal habitat- and region-specific combinations of control methods.

After an introduction and overview of the structure and the state of the Action, we briefly describe two planned activities typical for our Action, a study on the population dynamics of Ambrosia in different climates and habitats in Europe as a basis for estimating the efficiency of control measures, and an interdisciplinary study to clarify the impact the of North American native Ambrosia leaf beetle Ophraella communa Coleoptera.

Climate-change-induced range shifts of three allergenic ragweeds Ambrosia L. Full Text Available Invasive allergenic plant species may have severe health-related impacts. In this study we aim to predict the effects of climate change on the distribution of three allergenic ragweed species Ambrosia spp.

We estimate that by year , the distribution range of all three ragweed species increases towards Northern and Eastern Europe under all climate scenarios. We conclude that areas in Europe affected by severe ragweed associated allergy problems are likely to increase substantially by year , affecting millions of people.

To avoid this, management strategies must be developed that restrict ragweed dispersal and establishment of new populations. Precautionary efforts should limit the spread of ragweed seeds and reduce existing populations. Only by applying cross-countries management plans can managers mitigate future health risks and economical consequences of a ragweed expansion in Europe. Invasive allergenic plant species may have severe health-related impacts.

We quantify the extent of the increase in 'high allergy risk' HAR areas, i. Effects of climate change and seed dispersal on airborne ragweed pollen loads in Europe. Common ragweed Ambrosia artemisiifolia is an invasive alien species in Europe producing pollen that causes severe allergic disease in susceptible individuals.

Ragweed plants could further invade European land with climate and land-use changes. However, airborne pollen evolution depends not only on plant invasion, but also on pollen production, release and atmospheric dispersion changes.

To predict the effect of climate and land-use changes on airborne pollen concentrations, we used two comprehensive modelling frameworks accounting for all these factors under high-end and moderate climate and land-use change scenarios. We estimate that by airborne ragweed pollen concentrations will be about 4 times higher than they are now, with a range of uncertainty from 2 to 12 largely depending on the seed dispersal rate assumptions.

About a third of the airborne pollen increase is due to on-going seed dispersal, irrespective of climate change. The remaining two-thirds are related to climate and land-use changes that will extend ragweed habitat suitability in northern and eastern Europe and increase pollen production in established ragweed areas owing to increasing CO2. Therefore, climate change and ragweed seed dispersal in current and future suitable areas will increase airborne pollen concentrations, which may consequently heighten the incidence and prevalence of ragweed allergy.

Full Text Available Since the common ragweed , Ambrosia artemisiifolia , which was introduced from North America has also been found in Bavaria in larger stocks and has an increasing tendency to spread.

After receiving the report of the Bavarian Ministry of Health, the Bavarian Parliament addressed the implications for health. There was consensus across all political groups to combat the plant. The 96 district administration authorities, which each have a trained ragweed officer, report to the registration office on new verified ragweed locations with more than plants. The reports of common ragweed stands are filed by citizens or through research by the district administration authorities, who are also responsible for supporting the fight against stocks.

On behalf of the Bavarian Ministry of Health, the Working Group Biodiversity monitors the situation and finds many new locations. Since , new common ragweed stocks were registered. After control measures there are currently known remaining stocks. Since , however, the populated area has tripled. This means that the control measures need further improvement. This is especially true for the common ragweed stocks along roadsides where the plants have increased massively in recent years.

Sustainable control has proved to be particularly difficult. Ragweed -induced allergic rhinoconjunctivitis: Ragweed -induced allergic rhinoconjunctivitis has long been seen as a major immunologic condition in Northern America with high exposure and sensitization rates in the general population.

The invasive occurrence of ragweed A. Possible explanations for its worldwide spread are climate change and urbanization, as well as pollen transport over long distances by globalized traffic and winds. Due to the increasing disease burden worldwide, and to the lack of a current and comprehensive overview, this study aims to review the current and emerging treatment options for ragweed -induced rhinoconjunctivitis. Sound clinical evidence is present for the symptomatic treatment of ragweed -induced allergic rhinoconjunctivitis with oral third-generation H1-antihistamines and leukotriene antagonists.

The topical application of glucocorticoids has also been efficient in randomized controlled clinical trials. Combined approaches employing multiple agents are common. The mainstay of causal treatment to date, especially in Northern America, is subcutaneous immunotherapy with the focus on the major allergen, Amb a 1. Beyond this, growing evidence from several geographical regions documents the benefit of sublingual immunotherapy.

Future treatment options promise more specific symptomatic treatment and fewer side effects during causal therapy. Novel antihistamines for symptomatic treatment are aimed at the histamine H3-receptor. New adjuvants with toll-like receptor 4 activity or the application of the monoclonal anti-immunoglobulin E antibody, omalizumab, are supposed to enhance conventional immunotherapy.

An approach targeting toll-like receptor 9 by. Full Text Available The European Union handed over the regulation of common ragweed Ambrosia artemisiifolia to the member states. Austrian administration started to ask for control measures, i. Any sustainable control measure must focus on the reduction of seeds produced by the annual ragweed. Seed bank dimension of ragweed turned out to be a good evaluation tool for any control measure. To evaluate the importance of different spreading mechanisms of dispersal, a need for serious figures can be stated.

Based on our seed trap experiments and comparable slip stream experiments by German botanists, the efficiency of vehicles in spreading ragweed over long distances was low. However, machines used by road services cutter, moulder turned out to spread thousands of seeds.

Besides, there is serious indication that trucking agricultural food and seeds over long distances is relevant for ragweed seed dispersal. Dispersal of thousands of ragweed seeds from contaminated agricultural fields to fields not yet infested is caused by harvesters and other agricultural machines.

Regulations to reduce the ragweed load in traded agricultural goods are to be implemented in future. Small populations of ragweed should be simply uprooted and composted as long as they bear no flowers. Various possibilities are known for control of common ragweed in agricultural fields with mechanical and chemical methods. Limits are set in sunflowers because sunflower and ragweed are botanically related.

The legal obligation of reporting and control — introduced in Switzerland a couple of years ago — allowed the development of specific distribution maps and enhanced the quality of control measures. Facts and figures from the Canton of Geneva prove that the ragweed invasion has been stopped, but the species is not eradicated. The results of Geneva represent the results of good ragweed control in the whole country. Beside agriculture, traffic infrastructure, building sites, gravel pits and urban park and garden areas are sensible to ragweed invasion.

The responsibility of individuals helps to improve control efficiency even if financial funds are small. A sustainable control success depends on the efficiency to hamper seed production.

The reduction of pollen quantity in the air in a long term is part of the earnings for the control effort. Actually, the publicity of common ragweed is fed by specialist information and its distribution in the media. It would be an interesting task to develop in our fast moving era an awareness level comparable to that of the stinging nettle.

Effect of heavy metals on seed germination and seedling growth of common ragweed and roadside ground cover legumes. It creates empty niches vulnerable to weed establishment such as common ragweed Ambrosia artemisiifolia.

We hypothesized that heavy metal stresses may drive such species shifts along roadside edges. A positive relationship was noted between viruses and bacteria in both the pelagic and the benthic habitats.

Visibly virus-infected bacterial cells were uncommon in the pelagic habitat and undetectable in the benthos. Both lytic and lysogenic pelagic viral production rates were undetectable or low; thus, a possible explanation for the relative high viral abundances found in the water column could be an allochthonous input of viruses or release of sediment-derived viruses.

Overall, our results provide novel information about the relevance of viruses in the subarctic region and indicate that viruses play only a minor role in the nutrient and carbon cycling in the microbial communities of subarctic lakes.

Water -resources data, including stage and discharge data at most streamflow-gaging stations, are available throught the World Wide Web on the Internet. The Wisconsin District's home page is at http: Information on the Wisconsin District's Lakes Program is found at wi.

Water -quality and lake stage data for Wisconsin lakes , water year Information on the Wisconsin District's Lakes Program is found atwi. Viruses and bacteria in floodplain lakes along a major Amazon tributary respond to distance to the Amazon River. In response to the massive volume of water along the Amazon River, the Amazon tributaries have their water backed up by s of kilometers upstream their mouth.

This backwater effect is part of the complex hydrodynamics of Amazonian surface waters , which in turn drives the variation in concentrations of organic matter and nutrients, and also regulates planktonic communities such as viruses and bacteria. Viruses and bacteria are commonly tightly coupled to each other, and their ecological role in aquatic food webs has been increasingly recognized.

Here, we surveyed viral and bacterial abundances BAs in 26 floodplain lakes along the Trombetas River, the largest clear- water tributary of the Amazon River's north margin.

We correlated viral and BAs with temperature, pH, dissolved inorganic carbon, dissolved organic carbon DOC , phosphorus, nitrogen, turbidity, water transparency, partial pressure of carbon dioxide pCO2 , phytoplankton abundance, and distance from the lake mouth until the confluence of the Trombetas with the Amazon River.

We hypothesized that both bacterial and viral abundances VAs would change along a latitudinal gradient, as the backwater effect becomes more intense with increased proximity to the Amazon River; different flood duration and intensity among lakes and waters with contrasting sources would cause spatial variation. Our measurements were performed during the low water period, when floodplain lakes are in their most lake -like conditions.

Most viruses were bacteriophages, as viruses were strongly linked to bacteria , but not to phytoplankton. Our results highlight that hydrodynamics plays a key role in the regulation of planktonic viral and bacterial communities in Amazonian floodplain lakes.

The percentage of [methyl-3H]thymidine incorporated into samples from a dimictic eutrophic lake and retained on polycarbonate membranes of 3. Water samples were also examined by epifluorescence microscopy for evidence of algal senescence and bacterial colonization of intact and damaged cyanobacterial filaments. Epilimnetic samples also had a small percentage of cyanobacterial filaments, either intact or damaged, which were visibly colonized by bacteria in summer and fall samples.

The proportion of damaged cyanobacterial filaments was higher in these samples than in those from the epilimnion or from those obtained early in the summer. Furthermore, the filaments in these samples were more heavily colonized by bacteria.

It appears that the supply of colonizable particles damaged cyanobacterial filaments is an important factor affecting the level of particle-bound bacterial activity in this lake. Factors controlling bacteria and protists in selected Mazurian eutrophic lakes North-Eastern Poland during spring.

Background The bottom-up food resources and top-down grazing pressure controls, with other environmental parameters water temperature, pH are the main factors regulating the abundance and structure of microbial communities in aquatic ecosystems. It is still not definitively decided which of the two control mechanisms is more important. The significance of bottom-up versus top-down controls may alter with lake productivity and season.

The studied lakes were characterized by high nanoflagellate mean Among the staining methods used to examine bacterial cellular metabolic activity, the lowest percentage of active cells was recorded with the CTC 1. Conclusions In the euphotic zone, the bottom-up factors TP and DOC concentrations played a more important role than top-down control grazing by protists in regulating bacterial numbers and activity. Geological Survey USGS , in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin.

These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series. The locations of water -quality and lake -stage stations in Wisconsin for water year are shown in figure 1.

A water year is the month period from October 1 through September It is designated by the calendar year in which it ends. Thus, the period October 1, through September 30, is called ' water year Data collected include measurements of in- lake water quality and lake stage.

Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Vertical distribution of Archaea and Bacteria in a meromictic lake as determined by fluorescent in situ hybridization.

The prokaryotic cells distribution in the water column of the coastal saline meromictic Lake Faro Messina, Italy was investigated by microscopic counting techniques. Water samples were collected at a central station from the surface to the bottom, when waters were characterized by a marked stratification. A "red- water " layer, caused by a dense growth of photosynthetic sulfur bacteria , was present at a depth of 15 m, defining a transition area between oxic mixolimnion and anoxic monimolimnion layers.

Bacteria decreased from surface to bottom, while Archaea increased with depth and reached the maximum value at 30 m, where they outnumbered the Bacteria. Bacteria and picophytoplankton prevailed in the mixolimnion.

At the chemocline high numbers of prokaryotic cells were present, mainly represented by Cyanobacteria, Chromatium okenii and Euryarchaeota. Although Archaea constitute a minor fraction of microbial community, they could represent active contributors to the meromictic Lake Faro ecosystem. Effects of residential development on the water quality of Higgins Lake , Michigan Higgins Lake , a popular recreation area in the north-central Lower Peninsula of Michigan, drains an area of 58 square miles and is composed of two deep basins separated by a narrow channel between Flag Point and Point Detroit.

The North and South Basins have a maximum depth of about and feet respectively. The quality of the lake water near shore has been affected by residential development. The concentration of chloride and turbidity in the lake water near the shore increases with increases in building and road density.

Nitrogen concentration in lake water near shore also has increased the most in areas where buildings exceed a density of 0. Ground water beneath the lake showed higher concentrations of phosphorus, nitrogen, chloride, and boron than the lake-water samples. Phosphorus concentration in lake and ground water appears to be more affected by site-specific conditions, such as soil type and distance of sampling sites from individual septic systems, than by building density alone.

Energy and water in the Great Lakes. The nexus between thermoelectric power production and water use is not uniform across the U. That is, in some regions water demand for thermoelectric production is relatively small while in other regions it represents the dominate use. The later is the case for the Great Lakes region, which has important implications for the water resources and aquatic ecology of the Great Lakes watershed. This is today, but what about the future?

Projected demographic trends, shifting lifestyles, and economic growth coupled with the threat of global climate change and mounting pressure for greater U. Planning for such an uncertain future is further complicated by the fact that energy and environmental planning and regulatory decisionmaking is largely bifurcated in the region, with environmental and water resource concerns generally taken into account after new energy facilities and technologies have been proposed, or practices are already in place.

Based on these confounding needs, the objective of this effort is to develop Great Lakes -specific methods and tools to integrate energy and water resource planning and thereby support the dual goals of smarter energy planning and development, and protection of Great Lakes water resources. Guiding policies for this planning are the Great Lakes and St. The desired outcome of integrated energy- water -aquatic resource planning is a more sustainable regional energy mix for the Great Lakes basin ecosystem.

Great Lakes Energy- Water Model. Planning for such an uncertain future is further complicated by the fact that energy and environmental planning and regulatory decision-making is largely bifurcated in the region, with environmental and water resource concerns generally taken into account after new energy facilities and technologies have been proposed, or practices are already in place.

The location of water -quality and lake -stage stations in Wisconsin for water year are shown in figure 1. Thus, the period October 1, through September 30, is called ' water year '. Data collected include measurements of lake stage and in- lake water quality.

Graphs of Secchi depths, surface total-phosphorus and chlorophyll-a concentrations versus time are usually included for lakes with two or more years of data. Viability and potential for immigration of airborne bacteria from Africa that reach high mountain lakes in Europe. We have analysed the diversity of the bacteria , which grow after addition of concentrated airborne particles and desert dust in different microcosms combinations with water samples from oligotrophic alpine lakes.

We used, on the one hand, airborne bacteria transported by an African dust plume and collected in a high mountain area in the central Pyrenees Spain. On the other hand, we collected desert dust in Mauritania c.

In all the dust-amended treatments we consistently observed bacterial growth of common phyla usually found in freshwater ecosystems, i. Alpha-, Beta- and Gammaproteobacteria, Actinobacteria, and a few Bacteroidetes, but with different composition based on lake water pretreatment and dust type. Overall, we tentatively split the bacterial community in i typical freshwater non-airborne bacteria , ii cosmopolitan long-distance airborne bacteria , iii non-freshwater low-distance airborne bacteria , iv non-freshwater long-distance airborne soil bacteria and v freshwater non-soil airborne bacteria.

We identified viable long-distance airborne bacteria as immigrants in alpine lakes e. Sphingomonas-like but also viable putative airborne pathogens with the potential to grow in remote alpine areas Acinetobacter-like and Arthrobacter-like. Generation of atmospheric aerosols and remote dust deposition is a global process, largely enhanced by perturbations linked to the global change, and high mountain lakes are very convenient worldwide model systems for monitoring global-scale bacterial dispersion and pathogens entries in remote pristine environments.

Survival of lake trout eggs and fry reared in water from the upper Great Lakes. As part of continuing studies of the reproductive failure of lake trout Salvelinus namaycush in Lake Michigan, we measured the survival of lake trout eggs and fry of different origins and reared in different environments.

Eggs and milt were stripped from spawning lake trout collected in the fall of from southeastern Lake Michigan, northwestern Lake Huron, south central Lake Superior, and from hatchery brood stock.

Eggs from all sources were incubated, and the newly hatched fry were reared for days in lake water from each of the three upper Great Lakes and in well water. Comparisons of incubation water from the different lakes indicated that hatching success of eggs from all sources was highest in Lake Huron water , and lowest in Lake Michigan water.

The most notable finding was the nearly total mortality of fry from eggs of southeastern Lake Michigan lake trout. In a comparison of the rearing sites, little influence of water quality on fry survival was found. Thus, the poor survival was associated with the source of eggs and sperm, not the water in which the fry were reared. Coliform bacteria isolated from recreational lakes carry class 1 and class 2 integrons and virulence-associated genes.

To characterize the integron-harbouring Gram-negative bacteria in recreational lakes , with focus on the genetic content of integrons, antimicrobial resistance profiles and virulence-associated genes.

Antimicrobial resistance testing was done by disc diffusion method. Virulence-associated genes in integron-bearing Escherichia coli isolates were detected by PCR. A total of integron-bearing strains of coliform bacteria were cultured. Higher frequency of integron-positive bacteria and higher antimicrobial resistance ranges were noted in colder months January and November compared with spring and summer months. Integron-bearing multidrug resistant coliform bacteria carrying virulence genes are present in waters of recreational lakes.

This study presents antimicrobial resistance and virulence-associated genes in integron-bearing coliform bacteria present in the waters of recreational lakes , which showed that multidrug resistant bacteria with virulence traits might pose a threat to public health. Moreover, the presence of genes typical for enterotoxigenic and Shiga toxin-producing E. Lakes and Reservoir Management, vol. Due to the rapidly rising production and usage of nano-enabled products, aquatic environments are increasingly exposed to engineered nanoparticles ENPs , causing concerns about their potential negative effects.

In this study we assessed the effects of uncoated titanium dioxide nanoparticles TiO2NPs on the growth and activity of bacterial communities of three Swedish lakes featuring different chemical characteristics such as dissolved organic carbon DOC concentration, pH and elemental composition.

The nanoparticles were most stable in lake water with high DOC and low chemical element concentrations. The cell-specific bacterial activity was significantly enhanced at high TiO2NP exposure concentrations, indicating the loss of nanoparticle-sensitive bacteria and a subsequent increased activity by tolerant ones. We conclude that in freshwater lakes with high DOC and low chemical element concentrations, uncoated TiO2NPs show an enhanced stability and can significantly reduce bacterial abundance at relatively low exposure concentrations.

The Wisconsin Water Science Center's home page is at http: The effects of using ground water to maintain water levels of Cedar Lake , Wisconsin. There were no identifiable changes in measured physical and chemical characteristics of lake water during sustained pumping of ground water into the lake , nor were there identifiable changes in the number or makeup of the phytoplankton community.

Differences in physical and chemical characteristics of lake water and ground water added to the lake probably were not great enough to cause changes within the lake. Bacteria foraging in turbulent waters. Bacteria forage on patches of dissolved nutrients using chemotaxis, the ability to swim up chemical gradients.

As turbulence is ubiquitous in the Ocean, it is important to understand how turbulent flow conditions affect bacterial foraging. We used three-dimensional, isotropic direct numerical simulations coupled with a bacterial transport equation to address this problem. After the flow is continuously forced until it reaches a steady state, microscale nutrient patches are injected into the turbulent flow, and stirring produces thin nutrient filaments. Two populations of bacteria compete against each other: The distribution of both populations is initially uniform.

Chemotaxis allows active bacteria to cluster near the center of the nutrient filaments, increasing their nutrient uptake relative to passive bacteria.

Increasing the turbulence intensity increases the short-term chemotactic advantage by quickly producing large gradients in the nutrient concentration, but also leads to rapid mixing of the nutrient field, which makes the chemotactic advantage short-lived. The results suggest that the evolutionary advantage of chemotaxis, based on the increase in nutrient uptake relative to the energetic cost of swimming, strongly depends on the turbulence level.

Water -quality and lake -stage data for Wisconsin Lakes , water year Anaerobic ammonium-oxidizing anammox process can play an important role in freshwater nitrogen cycle.

However, the distribution of anammox bacteria in freshwater lake and the associated environmental factors remain essentially unclear. The present study investigated the temporal and spatial dynamics of sediment anammox bacterial populations in eutrotrophic Dianchi Lake and mesotrophic Erhai Lake on the Yunnan Plateau southwestern China.

The remarkable spatial change of anammox bacterial abundance was found in Dianchi Lake , while the relatively slight spatial shift occurred in Erhai Lake. Dianchi Lake had greater anammox bacterial abundance than Erhai Lake. In both Dianchi Lake and Erhai Lake , anammox bacteria were much more abundant in summer than in spring.

Anammox bacterial community richness, diversity, and structure in these two freshwater lakes were subjected to temporal and spatial variations. Sediment anammox bacterial communities in Dianchi Lake and Erhai Lake were dominated by Candidatus Brocadia and a novel phylotype followed by Candidatus Kuenenia; however, these two lakes had distinct anammox bacterial community structure. In addition, trophic status determined sediment anammox bacterial community structure.

The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes during water years — Thus, the period October 1, through September 30, is called " water year Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes , are available via the "USGS Annual Water Data Report" Web site: Our planet's surface waters are a fundamental resource encompassing a broad range of ecosystems that are core to global biogeochemical cycling, biodiversity and food and energy security.

Despite this, these same waters are impacted by multiple natural and anthropogenic pressures and drivers of environmental change. The complex interaction between physical, chemical and biological processes in surface waters poses significant challenges for in situ monitoring and assessment and this often limits our ability to adequately capture the dynamics of aquatic systems and our understanding of their status, functioning and response to pressures.

Recent developments in the availability of satellite platforms for Earth observation including ESA's Copernicus Programme offers an unprecedented opportunity to deliver measures of water quality at a global scale. The UK NERC-funded Globo Lakes project is a five-year research programme investigating the state of lakes and their response to climatic and other environmental drivers of change through the realization of a near-real time satellite based observatory Sentinel-3 and archive data processing MERIS, SeaWiFS to produce a year time-series of observed ecological parameters and lake temperature for more than lakes globally.

However, the diverse and complex optical properties of lakes mean that algorithm performance often varies markedly between different water types. The Globo Lakes project is overcoming this challenge by developing a processing chain whereby algorithms are dynamically selected according to the optical properties of the lake under observation.

The development and validation of the Globo Lakes processing chain has been supported by access to extensive in situ data from more than thirty partners around the world that are now held in the LIMNADES community-owned data repository developed under the auspices of Globo Lakes.

This approach has resulted in a step-change in our ability to produce regional and. Microbial water quality in freshwater lakes with different land use. The relationship between land use undeveloped, cattle grazing, urban , faecal indicator bacteria FIB levels and microbial source tracking MST marker detection was investigated in lakes created following phosphate mining.

FIB levels varied significantly by sampling date and were correlated with antecedent rainfall. FIB levels varied with land use category only in the case of faecal coliform levels in sediments of urban lakes , which were significantly greater than those in undeveloped or cattle-impacted lakes.

HPyVs was the only human source marker detected. Rainfall was more strongly associated with FIB levels than land use category. The detection frequency of only the ruminant MST marker was associated with land use.

Microbial source tracking MST can fine-tune the assessment of human health risk from recreational use of inland waters , particularly when similar FIB levels but different surrounding land use and probable impacts exist.

Denitrifying and anammox bacteria are involved in the nitrogen cycling in marine sediments but the environmental factors that regulate the relative importance of these processes are not well constrained. Here, we evaluated the abundance, diversity, and potential activity of denitrifying, anammox, and sulfide-dependent denitrifying bacteria in the sediments of the seasonally hypoxic saline Lake Grevelingen, known to harbor an active microbial community involved in sulfur oxidation pathways.

Depth distributions of 16S rRNA gene, nirS gene of denitrifying and anammox bacteria , aprA gene of sulfur-oxidizing and sulfate-reducing bacteria , and ladderane lipids of anammox bacteria were studied in sediments impacted by seasonally hypoxic bottom waters.

Samples were collected down to 5 cm depth 1 cm resolution at three different locations before March and during summer hypoxia August. The abundance of denitrifying bacteria did not vary despite of differences in oxygen and sulfide availability in the sediments, whereas anammox bacteria were more abundant in the summer hypoxia but in those sediments with lower sulfide concentrations. The simultaneous presence and activity of organoheterotrophic denitrifying bacteria , sulfide-dependent denitrifiers, and anammox bacteria suggests a tight network of bacteria coupling carbon-, nitrogen-, and sulfur cycling in Lake Grevelingen sediments.

Water -quality and lake -stage data for Wisconsin lakes , water years — Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes , are published online at http: Water -resources data, including stage and discharge data at most streamflow-gaging stations, are available online.

These data, accumulated over many years, provide a database for developing an improved understanding of the water quality of lakes. Time series of Secchi depths, surface total phosphorus, and chlorophyll a concentrations collected during nonfrozen periods are included for many lakes.

The purpose of this report is to provide information about the chemical and physical charac-teristics of Wisconsin lakes. Data collected include measure-ments of in- lake water quality and lake stage. Time series graphs of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes.

Descriptive infor-mation for each lake includes: Ecological dynamics of toxic Microcystis spp. Toxic cyanobacterial blooms directly threaten both human safety and the ecosystem of surface waters. The widespread occurrence of these organisms, coupled with the tumor-promoting properties of the microcystin toxins that they produce, demands action to mitigate their potential impacts and, thus, a robust understanding of their ecological dynamics.

In the present work, the abundance of toxic Microcystis spp. Samples were taken at monthly intervals from June to December at three sampling stations within this freshwater lake.

Results revealed that variation in the abundance of both total Microcystis spp. Importantly, we observed that peaks in mlrA gene copy numbers of MC-degrading bacteria occurred in the months following observed peaks in MC concentrations. To understand this phenomenon, we added MCs to the MC-degrading bacteria designated strains HW and SW in this study and found that MCs significantly enhanced mlrA gene copy numbers over the number for the control by a factor of 5.

These results indicate that toxic Microcystis and MC-degrading bacteria exert both direct and indirect effects on each other and that MC-degrading bacteria also mediate a shift from toxic to nontoxic populations of Microcystis.

The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes. Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are usually included for lakes with two or more years of data.

Vertical stratification of bacteria and archaea in sediments of a boreal stratified humic lake. Boreal stratified humic lakes , with steep redox gradients in the water column and in the sediment, are important sources of methane CH4 to the atmosphere.

CH4 flux from these lakes is largely controlled by the balance between CH4-production methanogenesis , which takes place in the organic rich sediment and in the deepest water layers, and CH4-consumption methanotrophy , which takes place mainly in the water column.

While there is already some published information on the activity, diversity and community structure of bacteria in the water columns of these lakes , such information on sediment microbial communities is very scarce. This study aims to characterize the vertical variation patterns in the diversity and the structure of microbial communities in sediment of a boreal stratified lake.

Particular focus is on microbes with the potential to contribute to methanogenesis fermentative bacteria and methanogenic archaea and to methanotrophy methanotrophic bacteria and archaea. The abundance of methanogenic archaea was also specifically studied by quantitative-PCR of methyl coenzyme-M reductase gene mcrA amplicons.

Furthermore, the community structure and the abundance of bacteria were studied by phospholipid fatty acid PLFA analysis. Dominant potential fermentative bacteria belonged to families Syntrophaceae, Clostridiaceae and Peptostreptococcaceae.

There were considerable differences in the vertical distribution among these groups. The relative abundance of Syntrophaceae started to increase from the sediment surface, peaked at depth layer from 5 to 10 cm up. Abundance and diversity of ammonia-oxidizing bacteria in relation to ammonium in a chinese shallow eutrophic urban lake. The measures of most-probable-number and restriction fragment length polymorphism analysis were used to analyze the abundance and diversity of ammonia-oxidizing bacteria in sediment of a Chinese shallow eutrophic urban lake Lake Yuehu.

Among the 5 sampling sites, ammonia concentration in interstitial water was positively proportional not only to the content of organic matter, but also to ammonia-oxidizing bacteria numbers at a magnitude of cells g-1 dry weight in sediment significantly.

Furthermore, the diversity of ammonia-oxidizing bacteria were determined by means of PCR primers targeting the amoA gene with five gene libraries created and restriction pattern analysis. The 13 restriction patterns were recorded with 4 ones being common among all sampling sites. Thus, the abundance and diversity of sediment AOB is closely linked to ammonium status in eutrophic lakes. According to the results of seasonal monitoring, in purple sulfur bacteria morphologically similar to Thiocapsa sp.

No pronounced seasonal periodicity in the total cell number in the water column was revealed during the period of observation. In some years cell number during the period when the lake was covered with ice was reliably higher than in summer. The absence ofseasonal periodicity was probably due to the low amplitude of seasonal variations in temperature and illumination in the redox zone, resulting from its relatively deep location m.

The year-to-year dynamics was characterized by a reliable decrease of the total cell number in and maxima in and Canonical correlation analysis revealed that water temperature in the redox zone was the best predictor of the PSB abundance in Lake Shira. Water temperature, in turn, depended on the depth of mixing of the water column. Intense mixing in was probably responsible for decreased PSB abundance in the lake.

On the other hand, the absence of deep winter mixing, resulting in stable conditions in the chemocline, favored the preservation of relatively high PSB biomass. Prediction of circulation depth, which. These results may be useful for paleolimnological reconstructions of the history of the lake based on the remnants of purple sulfur bacteria in bottom sediments.

The water levels of Lake Saumatre in Haiti and Lake Enriquillo in the Dominican Republic have been increasing continuously for the past years. As result roads and lake shore agriculture are flooded and there is an interest in determining the causes of the continuous lake growth and finding solutions to reverse the trend Various theories haven proposed for growth of the lakes such as climate change and deforestation.

Deforestation would affect the hydrological balance by means of changing infiltration rates. To examine the temporal variations in the lake , the lake surface areas during the past 30 years were obtained from available satellite data and converted into volumes. These lake surface areas showed a steady increase starting in for Lake Saumatre and in for Lake Enriquillo. Land cover change obtained by means of remote sensing for the years of and showed no significant change and could therefore be ruled out as a cause for the lake levels increases.

A simple water balance model that had been validated for monsoon climates matched the lake level volumes fluctuations well for the last 30 years including the recent rise in lake levels. Thus the lake level increases could be directly related to the greater precipitation starting some 10 years ago. The difference in starting time of lake level rise between the two lakes could be explained by a larger storage capacity in the a Lake Enriquillo watershed compared to the Lake Saumatre watershed.

Contamination of water resources by pathogenic bacteria. Water -borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water -borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole.

Providing a broader perceptive of pathogen contamination in freshwater rivers, lakes , reservoirs, groundwater and saline water estuaries and coastal waters resources, this review paper attempts to develop the first comprehensive single source of existing information on pathogen contamination in multiple types of water resources.

In addition, a comprehensive discussion describes the challenges associated with using indicator organisms. Potential impacts of water resources development on pathogen contamination as well as challenges that lie ahead for addressing pathogen contamination are also discussed.

Analysis of Ballast Water Discharges into the Great Lakes from Overseas Vessels from to - An assessment of the volume, location, and global port origins of ballast water discharges in the Great Lakes May Specific conductance identifies perched and ground water lakes. Shows that lakes can be classified into perched, ground water , and transitional categories according to specific conductance values. Confirms the classification with 10 years of water table measurements in 29 wells and discusses several applications of lake specific conductance values.

Labeling lake water with tritium. A method of packaging tritiated water in a manner that facilitates safe handling in environmental labeling operations, and procedures followed in labeling a large body of water with a small volume of tritiated water are described. Analysis of Poyang Lake water balance and its indication of river- lake interaction. In recent years, water shortage is becoming one of the most serious problems in the Poyang Lake.

In this paper, the long-term water balance items of the Poyang Lake have been analyzed to reveal the coupling effects of Three Gorges Dam TGD and droughts on the water balance of Poyang Lake. The results indicate that: Negative lake water balance in recent years leads to a serious water shortage problem in the Poyang Lake. Moreover, the operation of TGD also changed the river- lake relationship in the lower Yangtze River basin; 3 the coupling effects of drought and TGD on the lake water balance has been analyzed by using composite analysis method and it can be found that the operation of TGD has significantly altered the lake water balance.

But it is not the only factor that affects the lake water balance, and the droughts might cause their relations to be much more complicated. Lake Ontario Water Management. Background Ecosystem management requires organizing, synthesizing, and projecting information at a large scale while simultaneously addressing public interests, dynamic ecological properties, and a continuum of physicochemical conditions.

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Rainfall combined with northwest winds increased bacteria concentrations. Escherichia coli followed a seasonal trend with similar fluctuations in density among beaches.

We suggest that the current beach monitoring protocol is inadequate for predicting fecal coliform density at the time of beach closure, and, subsequently, its use for ensuring visitor safety remains questionable. Ammonia-oxidizing archaea and bacteria in water columns and sediments of a highly eutrophic plateau freshwater lake. Both ammonia-oxidizing archaea AOA and bacteria AOB can play important roles in the microbial oxidation of ammonia nitrogen in freshwater lake , but information on spatiotemporal variation in water column and sediment community structure is still limited.

Additionally, the drivers of the differences between sediment and water assemblages are still unclear. The abundance, diversity, and structure of both planktonic and sediment ammonia-oxidizing microorganisms in Dianchi Lake showed the evident changes with sampling site and time.

Surface water and sediment in the same location had a distinctively different microbial community structure. In addition, sediment AOB community structure was influenced by total phosphorus, while total phosphorus might be a key determinant of planktonic AOB community structure.

Prevalence of antibiotic-resistant bacteria in a lake for the storage of reclaimed water before and after usage as cooling water. Wastewater reclamation and reuse is a promising way to relieve water scarcity by substituting for natural water consumption by industrial cooling.

However, health concerns regarding cooling water originating from reclaimed water are increasing because an abundance of antibiotic-resistant bacteria ARB has been detected in reclaimed water. To assess the potential increase of ARB risks in reclaimed water after reuse for industrial cooling, the prevalence of six types of ARB was investigated in water and sediment samples from Lake Gaobeidian, which serves as an artificial circular storage reservoir for reclaimed water for cooling reuse.

The effect of treated wastewater and cooling water drainage on the ARB distribution in water and sediment samples was also studied.

The results showed that the concentration levels of six types of ARB in lake water samples were as high as those in treated wastewater. The annual median concentrations of total heterotrophic bacteria HPC and ARB in discharged cooling water after usage were 0. Lake Austin and Town Lake are impoundments on the Colorado River in Travis County, central Texas, and are a source of water for municipal industrial water supplies, electrical-power generation, and recreation for more than , people in the Austin metropolitan area.

Small vertical temperature variations in both lakes were attributed to shallow depths in the lakes and short retention times of water in the lakes during the summer months. The largest areal variations in dissolved oxygen generally occur in Lake Austin during the summer as a result of releases of water from below the thermocline in Lake Travis.

Except for iron, manganese, and mercury, dissolved concentrations of trace elements in water collected from Lake Austin and Town Lake did not exceed the primary or secondary drinking water standards set by the US Environmental Protection Agency. Little or no effect of stormwater runoff on temperature, dissolved oxygen, or minor elements could be detected in either Lake Austin or Town Lake.

Little seasonal or areal variation was noted in nitrogen concentrations in Lake Austin or Town lake. Total phosphorus concentrations generally were small in both lakes. Increased concentrations of nitrogen and phosphorus were detected after storm runoff inflow in Town Lake , but not in Lake Austin; densities of fecal-coliform bacteria increased in Lake Austin and Town Lake , but were substantially greater in Town Lake than in Lake Austin.

Magnetotactic bacteria from Pavilion Lake , British Columbia. It is known for unusual organosedimentary structures, called microbialites that are found along the lake basin.

These deposits are complex associations of fossilized microbial communities and detrital- or chemical-sedimentary rocks. During the summer, a sediment sample was collected from near the lake 's shore, approximately 25—50 cm below the water surface.

Magnetotactic bacteria MTB were isolated from this sample using a simple magnetic enrichment protocol. Transmission electron microscopy TEM revealed that the bacteria were spirillum-shaped and contained a single chain of cuboctahedral-shaped magnetite Fe3O4 crystals that were approximately 40 nm in diameter. This discovery of MTB in Pavilion Lake offers an opportunity to better understand the diversity of MTB habitats, the geobiological function of MTB in unique freshwater ecosystems, and search for magnetofossils contained within the lake 's microbialites.

A survey on cultivable heterotrophic bacteria inhabiting a thermally unstratified water column in an Atlantic Rainforest lake. Due to the importance of heterotrophic bacteria in biogeochemical cycles and their influence on water quality, many studies have assessed the composition of the bacterial community. Most of these were made in temperate freshwaters.

Eighteen heterotrophic bacteria communities distributed over time and space in the water column of Carioca Lake , not exposed to anthropogenic activities, were analyzed to characterize their composition. The physiological profiles among the 18 microbial communities were diverse.

Clustering analysis and the metabolic fingerprint of the Biolog EcoplateTM system data separated the communities based on temporal scale. A set of isolates were recovered on high nutrient medium. Most of the ARDRA patterns, OTUs, were from isolates obtained in a single sampling point, in temporal and spatial scales, indicating changes in the bacterial community.

The results of this work contribute to a better understanding about the phylogeny of tropical freshwater heterotrophic bacteria. Culture-based and culture-independent methods were used to explore the diversity of phototrophic purple bacteria in Soap Lake , a small meromictic soda lake in the western USA. Among soda lakes , Soap Lake is unusual because it consists of distinct upper and lower water bodies of vastly different salinities, and its deep waters contain up to mM sulfide. From Soap Lake water new alkaliphilic purple sulfur bacteria of the families Chromatiaceae and Ectothiorhodospiraceae were cultured, and one purple non-sulfur bacterium was isolated.

Comparative sequence analysis of pufM, a gene that encodes a key photosynthetic reaction centre protein universally found in purple bacteria , was used to measure the diversity of purple bacteria in Soap Lake. Denaturing gradient gel electrophoresis and subsequent phylogenetic analyses of pufMs amplified from Soap Lake water revealed that a significant diversity of purple bacteria inhabit this soda lake.

Although close relatives of several of the pufM phylotypes obtained from cultured species could also be detected in Soap Lake water , several other more divergent pufM phylotypes were also detected. It is possible that Soap Lake purple bacteria are major contributors of organic matter into the ecosystem of this lake , especially in its extensive anoxic and sulfidic deep waters.

Seasonal growth potential of rare lake water bacteria suggest their disproportional contribution to carbon fluxes. We studied the seasonal growth potential of opportunistic bacterial populations in Lake Zurich Switzerland by a series of grazer-free dilution culture assays.

Pronounced shifts in the composition of the bacterial assemblages were observed within one doubling of total cell numbers, from initially abundant Actinobacteria to other fast-growing microbial lineages. Small populations with growth potentials far above community average were detected throughout the year with striking seasonal differences in their respective taxonomic affiliations.

Members of Cytophaga-Flavobacteria CF were disproportionally proliferating only during phytoplankton blooms in spring and summer, while Beta- and Gammaproteobacteria showed superior growth at all other occasions. Growth rates of Alphaproteobacteria and esp.

Sphingomonadaceae were significantly correlated to water temperatures and were far above community average in summer. Within the genus Flavobacterium, two species-like populations showed a tendency for fast growth in most experiments, while four others were exclusively proliferating either during a spring or during a summer phytoplankton bloom.

Their high growth potentials but low in situ abundances hint at a tight control by bacterivorous grazers and at a consequently accelerated carbon flux to higher trophic levels. Stimulation of sulfate-reducing bacteria in lake water from a former open-pit mine through addition of organic wastes. A method to improve water quality in a lake occupying a former open-pit mine was evaluated in a laboratory-scale study. Varying amounts of two locally available organic waste products were added to pit water and maintained in microcosms under anoxic conditions.

In selected microcosms, populations of sulfate-reducing bacteria increased with time; sulfide was generated by sulfate reduction; sulfate, iron, and arsenic concentrations approached zero; and pH approached neutrality. Best results were obtained with intermediate amounts of waste potato skin. Rapid, automated separation of specific bacteria from lake water and sewage by flow cytometry and cell sorting.

The use of fluorescence-activated flow cytometric cell sorting to obtain highly enriched populations of viable target bacteria was investigated. Preliminary studies employed mixtures of Staphylococcus aureus and Escherichia coli. This was possible even when S. Cell sorting was also tested for the ability to recover E. The environmental samples were challenged with fluorescently labelled antibodies specific for E.

Biodegradation studies and sequencing of microcystin-LR degrading bacteria isolated from a drinking water biofilter and a fresh water lake. The presence of microcystin-LR -degrading bacteria in an active anthracite biofilter and in Lake Mead, Nevada was investigated. Four bacterial isolates from enrichment culture were identified using 16S rRNA analysis. Microcystin biodegradation tests were performed with both, the enrichment cultures and the respective isolates, using microcystin alone and acetate as carbon sources.

A newly recognized microcystin-degrading bacterium, Morganella morganii, was isolated from the biofilter and from Lake Mead. The results of the biodegradation tests indicated that addition of a carbon source acetate , significantly repressed the degradation of microcystin-LR.

The findings of this study inform on the prevalence of microcystin-degrading bacteria in the environment indicating bioaugmentation may not be needed, if biofiltration is used to remove microcystin from waters. The results also imply that, in a biofilter, biodegradable naturally organic matter NOM and microcystin will compete and therefore lower toxin removals are likely in waters with higher NOM content.

The feasibility of removing microcystin by biofiltration depends on the toxin concentration and the concentration of biodegradable carbon sources in the biofilter. Depth profiles of spectral and hydrological characteristics of water and their relation to abundances of green sulfur bacteria in the stratified lakes of the White Sea.

We analyze the results received from two expeditions performed in August-September , August-September and February in the Kandalaksha Bay of the White Sea. Depth profiles of hydrological characteristics and optical properties of water were recorded for five marine lakes being on different stages of isolation from the White Sea. Those relic lakes demonstrate a tendency to meromixis and are characterized by apparent stratification of the water bodies from the brackish top layer to the bottom salt water.

Maximal concentrations of anoxygenic phototrophs green sulfur bacteria were found at depths close to the redox interface in all the studied lakes. To discriminate differently pigmented groups of microorganisms the fluorescence emission spectra of bacteriochlorophylls from the living cells were used.

We puzzle out the data on light spectrum propagation through the water body in each lake using optical properties of water attenuation spectra in the UV, visible and NIR ranges, as well as direct measurements of the total irradiances at various depths. The changes in optical characteristics of water in the stratified reservoirs due to cromophoric dissolved organic matter CDOM and microbial pigments affect the light intensity and its spectral distribution at each water layer thus influencing the living conditions for differently pigmented phototrophic microorganisms and determining the composition of microbial community.

Effect of cadmium on lake water bacteria as determined by the luciferase assay of adenosine triphosphate. A firefly luciferase assay of bacterial adenosine triphosphate ATP was developed to measure the toxic effects of cadmium ions on aquatic organisms.

The bacteria , which belonged mainly to the families Enterobacteriaceae and Pseudomonadaceae, exhibited varying degrees of resistance to up to ppm cadmium when grown in a glucose-salts medium at pH 6.

Among the organisms tested, cadmium resistance decreased in the following order: A rise in the pH of the growth medium from 5 to 7 resulted in increased toxicity of cadmium. A guide to the natural history of freshwater lake bacteria.

Freshwater bacteria are at the hub of biogeochemical cycles and control water quality in lakes. Despite this, little is known about the identity and ecology of functionally significant lake bacteria.

Molecular studies have identified many abundant lake bacteria , but there is a large variation in the taxonomic or phylogenetic breadths among the methods used for this exploration.

Because of this, an inconsistent and overlapping naming structure has developed for freshwater bacteria , creating a significant obstacle to identifying coherent ecological traits among these groups. A discourse that unites the field is sorely needed. Here we present a new freshwater lake phylogeny constructed from all published 16S rRNA gene sequences from lake epilimnia and propose a unifying vocabulary to discuss freshwater taxa. With this new vocabulary in place, we review the current information on the ecology, ecophysiology, and distribution of lake bacteria and highlight newly identified phylotypes.

In the second part of our review, we conduct meta-analyses on the compiled data, identifying distribution patterns for bacterial phylotypes among biomes and across environmental gradients in lakes.

We conclude by emphasizing the role that this review can play in providing a coherent framework for future studies. Effects of water -column mixing on bacteria , phytoplankton, and rotifers under different levels of herbivory in a shallow eutrophic lake.

Water -column mixing is known to have a decisive impact on plankton communities. The underlying mechanisms depend on the size and depth of the water body, nutrient status and the plankton community structure, and they are well understood for shallow polymictic and deep stratified lakes. Two consecutive mixing events of similar intensity under different levels of herbivory were performed in enclosures in a shallow, but periodically stratified, eutrophic lake , in order to investigate the effects of water -column mixing on bacteria abundance, phytoplankton abundance and diversity, and rotifer abundance and fecundity.

When herbivory by filter-feeding zooplankton was low, water -column mixing that provoked a substantial nutrient input into the euphotic zone led to a strong net increase of bacteria and phytoplankton biomass.

Phytoplankton diversity was lower in the mixed enclosures than in the undisturbed ones because of the greater contribution of a few fast-growing species. After the second mixing event, at a high biomass of filter-feeding crustaceans, the increase of phytoplankton biomass was lower than after the first mixing, and diversity remained unchanged because enhanced growth of small fast-growing phytoplankton was prevented by zooplankton grazing. Bacterial abundance did not increase after the second mixing, when cladoceran biomass was high.

Changes in rotifer fecundity indicated a transmission of the phytoplankton response to the next trophic level. Our results suggest that water -column mixing in shallow eutrophic lakes with periodic stratification has a strong effect on the plankton community via enhanced nutrient availability rather than resuspension or reduced light availability.

This fuels the basis of the classic and microbial food chain via enhanced phytoplankton and bacterial growth, but the effects on biomass may be damped by high levels of herbivory. Environmental factors influencing the distribution of ammonifying and denitrifying bacteria and water qualities in 10 lakes and reservoirs of the Northeast, China. This study presents seasonal and spatial variations of the ammonifying bacteria AB and denitrifying bacteria DNB and physicochemical parameters in 10 lakes and reservoirs in the northeast of China.

Water samples were collected in winter January , spring March , summer July and fall November in Seasonally, the levels of AB presents gradually upward trend from winter to summer, and declines in fall and DNB were higher in spring and fall than summer and lowest in winter.

Thirteen water quality tests measuring five categories of pollution were conducted twice monthly from May, to April, at eight locations on Lake Sidney Lanier to establish baseline data and detect trends.

Additionally, sediment and water samples were analyzed for ten toxic metals. Sampling stations were located at or near the point of entry of streams into the Lake. Oxygen demanding pollutants were highest in urban streams and phosphorus and nitrogen concentrations were highest in streams having poultry processing operations within their watersheds. Indicators of siltation increased coincidentally with highway construction in one watershed.

Fecal coliform bacteria counts decreased at Flat Creek and increased in the Chattahoochee River. Zinc and copper occurred in water samples at levels of detectability.

Sediment samples from several locations contained metal concentrations which warrant further study. Streams are an important sink for anthropogenic N owing to their hydrological connections with terrestrial systems, but main factors influencing the community structure and abundance of denitrifiers in stream water remain unclear. To elucidate the potential impact of varying water properties of different streams on denitrifiers, the abundance and community of three denitrifying genes coding for nitrite nirK, nirS and nitrous oxide nosZ reductase were investigated in 11 streams inlets at the north part of Dianchi Lake.

The DGGE results showed the significant pairwise differences in community structure of nirK, nirS, and nosZ genes among different streams.

The results of redundancy analysis RDA confirmed that nitrogen and phosphorus concentrations, pH, and temperature in waters were the main environmental factors leading to a significant alteration in the community structure of denitrifiers among different streams.

Bacteria , archaea, and crenarchaeota in the epilimnion and hypolimnion of a deep holo-oligomictic lake. In a deep, subalpine holo-oligomictic lake , the relative abundance of Archaea and Crenarchaeota, but not that of Bacteria , increases significantly with depth and varies seasonally.

Cell-specific prokaryotic productivity is homogeneous along the water column. The concept of active Archaea observed in the deep ocean can therefore be extended to a deep oxic lake. Antibiotic concentration and antibiotic-resistant bacteria in two shallow urban lakes after stormwater event. Stormwater runoff is generally characterized as non-point source pollution. In the present study, antibiotic concentration and antibiotic susceptibilities of cultivable heterotrophic bacteria were investigated in two small shallow urban lakes before and after strong storm event.

In general, the frequencies of bacteria showing resistance to nine antibiotics increased after storm event. Based on the 16S rRNA genes of 50 randomly selected isolates from each water sample of two lakes , Aeromonas and Bacillus were dominant genera in samples from two lakes , while genera Proteus and Lysinibacillus were the third abundant genera in Lake Xuanwu and Wulongtu, respectively.

Presences of nine antibiotic resistance genes ARGs in the isolates were detected and most of these isolates harbored at least two ARGs with different functions. The detection frequency of ARGs in Gram-negative isolates was higher than that in Gram-positive isolates. Our results indicate that strong storm events potentially contribute to the transfer of ARGs and antibiotic-resistant bacteria from land-sewer system to the urban Lakes.

Cold-active halophilic bacteria from the ice-sealed Lake Vida, Antarctica. Lake Vida is a large, permanently ice-covered lake in the Victoria Valley of the McMurdo Dry Valleys, Antarctica and is unique among Dry Valley lakes because it is ice-sealed, with an ice-cover of nearly 19 m.

Enrichment cultures of melt- water from Lake Vida Of these, one strain grew at -8 degrees C and the four others at -4 degrees C. Phylogenetic analysis revealed the Lake Vida isolates to be Gammaproteobacteria, related to species of Psychrobacter and Marinobacter. This is the first report of pure cultures of bacteria from Lake Vida, and the isolates displayed a phenotype consistent with life in a cold hypersaline environment.

The spatial distribution of enteric bacteria in the Jordan River- Lake Kinneret contact zone. Lake Kinneret, in the north of Israel, is the only freshwater body in the country.

It supports many activities, including recreation, tourism, and a commercial fishing industry, but its prime function is to supply water to other parts of the country. Consequently, maintaining a high water quality of the lake is of prime importance.

During this period, the river carries sediments, toxic agricultural chemicals, and allochthonous organisms, including pathogenic bacteria , into the lake. The Jordan River- Lake Kinneret contact zone is characterized by a rapid transformation from a riverine to a lacustrine water mass within m from the river mouth, with very high spatial gradients of practically all hydrodynamic, hydrophysical, hydrochemical, and microbiological parameters.

Previous measurements have shown that the distribution of enteric bacteria in the river- lake contact zone is related to the attenuation of river current flows. The aim of this study was to determine whether the change in the number of enteric bacteria fecal coliforms, Escherichia coli, and Klebsiella spp. The data were then utilized to build a conceptual model explaining the distribution of biological pollutants bacteria in the river- lake contact zone of a shallow tropical lake , using the microbial communities of the River Jordan- Lake Kinneret contact zone, as an example.

Water -quality data collected from Lake Austin and Town Lake , following runoff, generally were not adequate to fully determine the effects of runoff on the lakes. Data collection should not to be limited to fixed-station sampling following runoff, and both lakes need to be sampled simultaneously as soon as possible following significant precipitation.

From the water column of Lake Baikal, several strains of prosthecate bacteria belonging to the genera Caulobacter and Brevundimonas were isolated. In this article, the methods applied for their isolation and cell number determination are described; the occurrence frequency and spatial distribution of these microorganisms in the lake are demonstrated. Characterization of the species composition of cultivable and uncultivable prosthecate bacteria was carried out using the methods of traditional and molecular microbiology, respectively.

A comparative phylogenetic analysis of the DNA sequences of uncultivable bacteria , which showed homology to the members of the alpha subclass of proteobacteria, was carried out. It was demonstrated that the lake water column is inhabited by uncultivable alpha-proteobacteria of uncertain phylogenetic affinity, in addition to representatives of the species Caulobacter vibrioides and C.

Lake Vostok, the largest subglacial lake in Antarctica, is separated from the surface by approximately 4 km of glacial ice. It has been isolated from direct surface input for at least years, and the possibility of a novel environment and ecosystem therefore exists.

Lake Vostok water has not been sampled, but an ice core has been recovered that extends into the ice accreted below glacial ice by freezing of Lake Vostok water. Here, we report the recovery of bacterial isolates belonging to the Brachybacteria, Methylobacterium, Paenibacillus and Sphingomonas lineages from a sample of melt water from this accretion ice that originated m below the surface.

Pore water chemistry of an alkaline rift valley lake: Lake Turkana is the largest closed basin lake in the African rift system. It has evolved through the past years to become a moderately alkaline lake. Previous mass balance argument suggest that sulfate is removed from the lake by sulfate reduction in the sediments, and that the lake is accumulating in chloride, sodium, and alkalinity.

Studies of pore water from 12 meter cores collected in November show that sulfate is reduced in the sediment column with a net production of alkalinity.

Some sodium is lost from the lake and diffuses into the sediment to maintain charge balance. Magnesium and calcium molar ratios change with depth; chloride, sodium, and alkalinity also change with depth.

Methanotrophic bacteria are globally significant due to their role as a major biological sink for methane, a greenhouse gas. These microorganisms are especially active at interfaces where methane and oxygen meet. Methanotrophs are also of environmental interest because of their ability to co-metabolize many common organic pollutants including halogenated and aromatic hydrocarbons. Lake Mishawum in Woburn, MA, is a shallow, permanently stratified lake with an anoxic, methane-rich hypolimnion and an oxic epilimnion.

This unique stratification is maintained because the bottom water continually receives inputs of salty groundwater, while the upper layer is fed by rainwater runoff. Modeling of methane concentration profiles in the lake showed high rates of methane oxidation at the oxic-anoxic interface. Hence, methanotrophs have been postulated to be a significant and active population of the bacteria residing in the lake 's metalimnion. The diversity, abundance, and seasonal variation of methanotrophic bacteria at this interface was investigated using PCR gene diversity studies, quantitative PCR QPCR , and cultures of methane-oxidizing isolates from metalimnion water samples.

Gene diversity and isolate analyses revealed that as in other saline lakes , both Type I and Type II methanotrophs were present at the interface. QPCR studies using the methanol dehydrogenase gene showed that their populations comprised up to 15 percent of the total bacterial population in the summer months.

Year long QPCR studies of methanotrophs populations at the Lake Mishawum interface indidcated that, while total bacteria numbers do not change over time, methanotroph population size varied seasonally and correlated with temperature changes in the lake.

These results suggest that methanotrophs are a diverse and highly active population in the oxic-anoxic interface of Lake Mishawum. The finding of both Type I and Type II methanotrophs at the interface calls into question the role of these two. Enrichment of sulfate-reducing bacteria and resulting mineral formation in media mimicking pore water metal ion concentrations and pH conditions of acidic pit lakes.

Acid mine drainage sites are extreme environments with high acidity and metal ion concentrations. Under anoxic conditions, microbial sulfate reduction may trigger the formation of secondary minerals as a result of H2S production and pH increase.

At initial pH values of 5 and 6, sulfate reduction occurred shortly after inoculation. Sulfate- reducing bacteria affiliated to the genus Desulfosporosinus predominated the microbial communities as shown by 16S rRNA gene analysis performed at the end of the incubation.

At initial pH values of 3 and 4, sulfate reduction and cell growth occurred only after an extended lag phase, however, at a higher rate than in the less acidic assays. At the end of the growth phase, enrichments were dominated by Thermodesulfobium spp. Iron sulfides in the bulk phase were common in all assays, but specific aluminum precipitates formed in close association with cell surfaces and may function as a detoxification mechanism of dissolved Al species at low pH.

Removal and inactivation of bacteria during alum treatment of a lake. Flocculation and removal of bacteria were observed during two separate aluminum sulfate alum treatments for removal of phosphorus from a eutrophic recreational lake. In addition, die-off and release of bacteria from alum floc were studied in columns under laboratory conditions. Membrane filtration and spread plates were used to determine concentrations of indicator species and total cultivatable bacteria , respectively.

The numbers of and survival of E. Thus, the floc poses a potential human health risk if ingested by swimmers or if others use the lake as a potable water source. Bacteria and emerging chemical contaminants in the St.

Introduction Since the enactment of the Clean Water Act in , awareness of the quality of the Nation's water has continued to improve. Despite improvements to wastewater-treatment systems and increased regulation on waste discharge, bacterial and chemical contamination is still a problem for many rivers and lakes throughout the United States. Pathogenic microorganism and newly recognized chemical contaminants have been found in waters that are used for drinking water and recreation Rose and Grimes, ; Kolpin and others, This summary of bacteria and emerging-chemical-contaminant monitoring in the St.

Clair, and Wayne, and the U. We employed culture-dependent and -independent techniques to study microbial diversity in Lake Chaka, a unique hypersaline lake It is situated at 3, m above sea level in a dry climate. The average water depth is 2 to 3 cm. Halophilic isolates were obtained from the lake water , and halotolerant isolates were obtained from the shallow sediment.

The isolates exhibited resistance to UV and gamma radiation. A major change in the bacterial community composition was observed across the interface. A similar change was also present in the archaeal community. While all archaeal clone sequences in the lake water belonged to the Halobacteriales, the majority of the sequences in the sediments were related to those previously obtained from methanogenic soils and sediments.

The observed changes in the microbial community structure across the water -sediment interface were correlated with a decrease in salinity from the lake water Across the interface, the redox state also changed from oxic to anoxic and may also have contributed to the observed shift in the microbial community.

Long-term population dynamics of phototrophic sulfur bacteria in the chemocline of Lake Cadagno, Switzerland. Population analyses in water samples obtained from the chemocline of crenogenic, meromictic Lake Cadagno, Switzerland, in October for the years to were studied using in situ hybridization with specific probes. During this year period, large shifts in abundance between purple and green sulfur bacteria and among different populations were obtained.

All populations of purple sulfur bacteria showed large fluctuations in time with populations belonging to the genus Lamprocystis being numerically much more important than those of the genera Chromatium and Thiocystis. Green sulfur bacteria were initially represented by Chlorobium phaeobacteroides but were replaced by Chlorobium clathratiforme by the end of the study. At this time, numbers of purple sulfur bacteria had decreased and those of green sulfur bacteria increased by about 1 order of magnitude and C.

This major change in community structure in the chemocline was accompanied by changes in profiles of turbidity and photosynthetically available radiation, as well as for sulfide concentrations and light intensity. Overall, these findings suggest that a disruption of the chemocline in may have altered environmental niches and populations in subsequent years. Grazing of the copepod Diaptomus connexus on purple sulphur bacteria in a meromictic salt lake.

A meromictic lake ecosystem Mahoney Lake , BC, Canada was investigated to elucidate the significance of chemocline bacteria in the total carbon cycle under natural conditions. In this lake , primary production by oxygenic phototrophs was insufficient to support the observed net secondary production of the calanoid copepod Diaptomus connexus and the rotifer Brachionus plicatilis, indicating the presence of additional food sources for consumers.

Mahoney Lake harbours the densest population of phototrophic sulphur bacteria ever reported in a natural body of water. This layer is located at the interface between oxic and anoxic water layers and is dominated by the purple sulphur bacterium Amoebobacter purpureus. The transfer rates of A. Stable stratification within the mesocosms prevented an upwelling of A.

However, measurements of carbon fluxes, infrared fluorescence microscopy and stable carbon analysis provided cumulative evidence that, under in situ conditions, the cell carbon of purple sulphur bacteria indeed enters the aerobic food chain via the grazing activity of D. Based on a two-source isotopic mixing model, A. Autumnal upwelling into oxic water layers and aggregation of A.

Lake water quality mapping from Landsat. In the project described remote sensing was used to check the quality of lake waters. Moreover, these enzymes establish an unexpected link between the synthesis of bacterial cell-wall polymers and other biological processes. In the present review, the current knowledge in the field of the bacterial lipid carrier, its mechanism of action, biogenesis, recycling, regulation, and future perspective works are presented. Plants are able to generate large leaf surfaces that act as two-dimensional solar panels with a minimum investment in building material, thanks to a hydrostatic skeleton.

This requires high intracellular pressures up to 1 MPa , which depend on the presence of strong cell walls. The walls of growing cells also called primary walls , are remarkably able to reconcile extreme tensile strength up to MPa with the extensibility necessary for growth. All walled organisms are confronted with this dilemma - the need to balance strength and extensibility - and bacteria, fungi and plants have evolved independent solutions to cope.

In this Primer, we discuss how plant cells have solved this problem, allowing them to support often very large increases in volume and to develop a broad variety of shapes Figure 1A,B,D. This shape variation reflects the targeted deposition of wall material combined with local variations in cell-wall extensibility, processes that remain incompletely understood. Once the cell has reached its final size, it can lay down secondary wall layers, the composition and architecture of which are optimized to exert specific functions in different cell types Figure 1E-G.

Specialized secondary walls , such as those constituting seed mucilage, are stored in a dehydrated form in seedcoat epidermis cells and show rapid swelling upon hydration of the seed. Other walls , in particular in reserve tissues, can accommodate large amounts of storage polysaccharides, which can be easily mobilized as a carbon source. Physiological and transcriptional responses of Saccharomyces cerevisiae to d-limonene show changes to the cell wall but not to the plasma membrane.

Monoterpenes can, upon hydrogenation, be used as light-fraction components of sustainable aviation fuels. Fermentative production of monoterpenes in engineered microorganisms, such as Saccharomyces cerevisiae, has gained attention as a potential route to deliver these next-generation fuels from renewable biomass.

However, end product toxicity presents a formidable problem for microbial synthesis. Due to their hydrophobicity, monoterpene inhibition has long been attributed to membrane interference, but the molecular mechanism remains largely unsolved. We found no alterations in membrane fluidity, structural membrane integrity, or fatty acid composition after the solvent challenge. A 4-fold increase in the mean fluorescence intensity per cell using calcofluor white stain and increased sensitivity to cell wall -degrading enzymes demonstrated that limonene disrupts cell wall properties.

Global transcript measurements confirmed the membrane integrity observations by showing no upregulation of ergosterol or fatty acid biosynthesis pathways, which are commonly overexpressed in yeast to reinforce membrane rigidity during ethanol exposure.

This is the first report demonstrating that cell wall , rather than plasma membrane , deterioration is the main source of monoterpene inhibition.

We show that limonene can alter the structure and function of the cell wall , which has a clear effect on cytokinesis. Proteins in the cell wall and membrane of Cryptococcus neoformans stimulate lymphocytes from both adults and fetal cord blood to proliferate. Cryptococcus neoformans is an encapsulated yeast that infects patients who have defective cell -mediated immunity, including AIDS, but rarely infects individuals who have intact cell -mediated immunity.

Studies of the immune response to C. The goal of this study was to separate C. The lymphocyte response to fungal culture medium, whole organisms, disrupted organisms, and the yeast intracellular fraction or cell wall and membrane was studied by determining thymidine incorporation and by determining the number of lymphocytes at various times after stimulation.

The cell wall and membrane of C. The optimal response occurred on day 7 of incubation, with 4 x 10 5 peripheral blood mononuclear cells per well and with 13 microg of cryptococcal protein per ml.

The number of lymphocytes increased with time in culture, indicating that thymidine incorporation was accompanied by proliferation. Proteinase K treatment of the cell wall and membrane abrogated lymphocyte proliferation, indicating that the molecule was a protein. At least 18 discrete bands were resolved from the cell wall and membrane. Since a large percentage of healthy adults responded to the cryptococcal cell wall and membrane , a mitogenic effect was investigated by testing proliferation of fetal cord blood.

An investigation into plasmolysis in the oomycete Achlya bisexualis reveals that membrane-wall attachment points are sensitive to peptides containing the sequence RGD and that cell wall deposition can occur despite retraction of the protoplast. The structure and function of membrane-wall attachment sites in walled cells , and how these relate to animal focal adhesions, is an area that is poorly understood.

In view of this, we investigated how membrane-wall attachments that form upon plasmolysis, respond to peptides that disrupt animal focal adhesions. The degree of cytoplasmic disruption during plasmolysis was also investigated. Upon hyperosmotic challenge, the protoplast in hyphae of the oomycete Achlya bisexualis typically retracted incompletely due to membrane-wall attachments. The inclusion, in the plasmolysing solution, of peptides containing the sequence RGD disrupted these attachments in a dose-dependent manner.

In some hyphae, protoplast retraction stopped temporarily at attachment points - upon resumption of retraction, material was left that traced the outline of the static protoplast. Staining of this material with fluorescence brightener indicated the presence of cellulose, which suggests that wall deposition was able to occur despite plasmolysis. The F-actin cytoskeleton was disrupted during plasmolysis; peripheral F-actin staining was observed, but there was no distinct F-actin cap; staining was more diffuse; and there were fewer plaques compared with nonplasmolysed hyphae.

Our data indicate that membrane-wall attachment points are sensitive to RGD-containing peptides and that wall deposition continues despite protoplast retraction and F-actin disruption.

Genome-wide reprogramming of regulatory networks, transport, cell wall and membrane biogenesis during arbuscular mycorrhizal symbiosis in Lotus japonicus. As a consequence of the fungal colonization and of the deep reorganization shown by arbusculated cells , important impacts on root transcriptome are expected. Induction of a subset 24 genes of these was tested and confirmed by qRT-PCR, and transcript location in arbusculated cells was demonstrated for seven genes using laser-dissected cells.

Improving the electro-transformation efficiency of Corynebacterium glutamicum by weakening its cell wall and increasing the cytoplasmic membrane fluidity. To improve the transformation efficiency of Corynebacterium glutamicum cells with heterogenous plasmid DNA and single-strand DNA ssDNA using a methodology based on electro-transformation. A semicomplex hypertonic medium was selected with addition of glycine and DL-threonine to weaken cell walls and addition of Tween 80 and isonicotinic acid hydrazide to increase cytoplasmic membrane fluidity.

Their contents were optimized by response surface methodology. Cell growth, electro-transformation buffer, and transformation protocol were also optimized. Temporary heating inactivation of the host restriction enzyme showed a significant effect. Finally, a high transformation efficiency of 3. The results shed light on the application in functional genomics and genome editing of C. The rice dynamin-related protein DRP2B mediates membrane trafficking, and thereby plays a critical role in secondary cell wall cellulose biosynthesis.

Membrane trafficking between the plasma membrane PM and intracellular compartments is an important process that regulates the deposition and metabolism of cell wall polysaccharides. Dynamin-related proteins DRPs , which function in membrane tubulation and vesiculation are closely associated with cell wall biogenesis.

However, the molecular mechanisms by which DRPs participate in cell wall formation are poorly understood. Consistent with the expression of BC3 in mechanical tissues, the bc3 mutation reduces mechanical strength, which results from decreased cellulose content and altered secondary wall structure.

Subcellular localization of fluorescence-tagged OsDRP2B and several compartment markers in protoplast cells showed that this protein not only lies at the PM and the clathrin-mediated vesicles, but also is targeted to the trans-Golgi network TGN. An FM uptake assay in transgenic plants that express green fluorescent protein-tagged OsDRP2B verified its involvement in an endocytic pathway.

All of these findings lead us to conclude that OsDRP2B participates in the endocytic pathway, probably as well as in post-Golgi membrane trafficking. Mutation of OsDRP2B disturbs the membrane trafficking that is essential for normal cellulose biosynthesis of the secondary cell wall , thereby leading to inferior mechanical properties in rice plants.

Enzymatic biofuel cells EBFCs utilize enzymes to convert chemical energy present in renewable biofuels into electrical energy and have shown much promise in the continuous powering of implantable devices. Currently, however, EBFCs are greatly limited in terms of power and operational stability with a majority of reported improvements requiring the inclusion of potentially toxic and unstable electron transfer mediators or multicompartment systems separated by a semipermeable membrane resulting in complicated setups.

Glucose oxidase and bilirubin oxidase were physically adsorbed onto these electrodes to form anodes and cathodes, respectively, and the EBFC produced power densities up to 0. Further, the electrodes were rejuvenated by a simple wash and reloading procedure. We postulate these porous and ultrahigh surface area electrodes will be useful for biosensing applications, and will allow reuse of EBFCs.

In this study the elastic spring constant of the yeast cell wall is probed with the atomic force microscope AFM under variable conditions. Cells were sequentially analyzed in rich growth medium YPD , a 0. Cells in late log phase, which have variable diameters within three to five microns, were immobilized on a patterned silicon substrate with holes approximately 3.

Force curves were taken moving laterally across the cell in one dimension after exposure to each medium. Spring constants of the cells , calculated from force curves, displayed a positional dependency and marked differences in high osmolarity medium and after the injection of sodium azide.

This study demonstrates the ability of the AFM to investigate changes in cell morphology and correlate those findings to underlying physiological processes. The Lamportian cell wall. The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks.

The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined.

Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: An electrochemical impedance spectroscopy study of polymer electrolyte membrane fuel cells electrocatalyst single wall carbon nanohorns-supported.

Additionally, as-prepared and oxidized SWNH Pt-supports were compared with conventional carbon black. Two different oxidizing treatments were considered: Both oxidizing treatments increased SWNH surface area; oxygen treatment increased surface area 4 times while acid treatment increased 2. The increase in surface area should be related to the opening access to the inner tube of SWNH.

On the other hand, the oxygen treated SWNH sample allowed to obtain the highest electrocatalyst load. Moreover, EIS analysis indicated that the major improvement in performance is related to the cathode kinetics in the as-prepared SWNH sample, while concerning the oxidized SWNH sample, the improvements are related to the electrokinetics in both anode and cathode electrodes. These improvements should be related with differences in the hydrophobic character between SWNH and carbon black.

Lipoprotein cofactors located in the outer membrane activate bacterial cell wall polymerases. Most bacteria surround themselves with a peptidoglycan PG exoskeleton synthesized by polysaccharide polymerases called penicillin-binding proteins PBPs. Because they are the targets of penicillin and related antibiotics, the structure and biochemical functions of the PBPs have been extensively studied. Overall, our results indicate that PBP accessory proteins play a central role in PG biogenesis, and like the PBPs they work with, these factors are attractive targets for antibiotic development.

Stabilization of glucose-C in microbial cell membranes PLFA and cell walls amino sugars evaluated by 13C-labelling in a field experiment. Microorganisms control carbon C cycle and strongly contribute to formation of soil organic matter. Strong differences in the turnover of microbial groups and cellular compounds complicate the assessment of their contribution to microbial food webs and C sequestration in soil in situ.

The uptake and incorporation of 13C labeled glucose by microbial groups were traced during 50 days after the labeling under field conditions. This allowed tracing C in microbial groups as well as cellular compounds.

Such long cytosol MRT depends on its heterogeneous composition, which includes high and low molecular weight organics. Amino sugars were mainly originated from microbial residues and thus, observation periods higher than 1 year are required for estimation of their MRT.

Relative 13C incorporation into amino sugars of living microorganisms showed only 0. Therefore, the turnover of cell membrane components is two times faster than that of cell walls , even in living microorganisms.

Consequently, bacteria contribute more to the decomposition of low molecular weight organics, whereas fungi consume bacterial products or necromass and contribute more to long-term C stabilisation. Thus, tracing of 13C in cellular. Hydroxylation of multi- walled carbon nanotubes: Enhanced biocompatibility through reduction of oxidative stress initiated cell membrane damage, cell cycle arrestment and extrinsic apoptotic pathway.

Modification of CNTs with hydroxyl group promotes their applications in biomedical area. However, the impact of hydroxylation on their biocompatibility is far from being completely understood.

More interestingly, MWCNTs-OH exhibited significantly lower tendency to activate caspase-8, a key molecule involved in the extrinsic apoptotic pathway. Arabidopsis NDR1 is an integrin-like protein with a role in fluid loss and plasma membrane-cell wall adhesion. Whereas the genetic requirement for NDR1 in plant disease resistance signaling has been detailed, our study focuses on determining a global, physiological role for NDR1. Specific protein motifs also point to a degree of homology with mammalian integrins, well-characterized proteins involved in adhesion and signaling.

This structural homology led us to examine a physiological role for NDR1 in preventing fluid loss and maintaining cell integrity through plasma membrane-cell wall adhesions.

Our results show a substantial alteration in induced i. As an extension of these analyses, using a combination of genetic and cell biology-based approaches, we have identified a role for NDR1 in mediating plasma membrane-cell wall adhesions.

Taken together, our data point to a broad role for NDR1 both in mediating primary cellular functions in Arabidopsis through maintaining the integrity of the cell wall -plasma membrane connection and as a key signaling component of these responses during pathogen infection.

Fungal cell wall organization and biosynthesis. The composition and organization of the cell walls from Saccharomyces cerevisiae, Candida albicans, Aspergillus fumigatus, Schizosaccharomyces pombe, Neurospora crassa, and Cryptococcus neoformans are compared and contrasted.

A comparison of these cell walls shows that there is a great deal of variability in fungal cell wall composition and organization. However, in all cases, the cell wall components are cross-linked together to generate a cell wall matrix.

The biosynthesis and properties of each of the major cell wall components are discussed. The chitin and glucans are synthesized and extruded into the cell wall space by plasma membrane -associated chitin synthases and glucan synthases.

The glycoproteins are synthesized by ER-associated ribosomes and pass through the canonical secretory pathway. Over half of the major cell wall proteins are modified by the addition of a glycosylphosphatidylinositol anchor. The cell wall glycoproteins are also modified by the addition of O-linked oligosaccharides, and their N-linked oligosaccharides are extensively modified during their passage through the secretory pathway.

These cell wall glycoprotein posttranslational modifications are essential for cross-linking the proteins into the cell wall matrix. Cross-linking the cell wall components together is essential for cell wall integrity. The activities of four groups of cross-linking enzymes are discussed.

Cell wall proteins function as cross-linking enzymes, structural elements, adhesins, and environmental stress sensors and protect the cell from environmental changes. Cell wall proteins are essential constituents of plant cell walls ; they are involved in modifications of cell wall components, wall structure, signaling and interactions with plasma membrane proteins at the cell surface.

The application of proteomic approaches to the cell wall compartment raises important questions: What kinds of proteins can be found in Arabidopsis walls? Are some of them unexpected? What sort of post-translational modifications have been characterized in cell wall proteins to date? The purpose of this review is to discuss the experimental results obtained to date using proteomics, as well as some of the new questions challenging future research.

Mechanism of anchoring of OmpA protein to the cell wall peptidoglycan of the gram-negative bacterial outer membrane. The outer membrane protein A OmpA plays important roles in anchoring of the outer membrane to the bacterial cell wall. However, there is a paucity of information on the structural aspects of the mechanism of PGN recognition by OmpA-like domains. To elucidate this molecular recognition process, we solved the high-resolution crystal structure of an OmpA-like domain from Acinetobacter baumannii bound to diaminopimelate DAP , a unique bacterial amino acid from the PGN.

These structural data provide a detailed glimpse of how the anchoring of OmpA to the cell wall of gram-negative bacteria takes place in a DAP-dependent manner. The pit membrane PM is a primary cell wall barrier that separates adjacent xylem water conduits, limiting the spread of xylem-localized pathogens and air embolisms from one conduit to the next. This paper provides a characterization of the size of the pores in the PMs of grapevine Vitis vinifera.

Stems were infused with pressurized water and flow rates were determined; gold particles of known size were introduced with the water to assist in determining the size of PM pores. The possibility that cell wall -degrading enzymes could alter the pore sizes, thus facilitating the ability of X. Two cell wall -degrading enzymes likely to be produced by X.

Scanning electron microscopy of control and enzyme-infused stem segments revealed that the combination of enzymes opened holes in PMs, probably explaining enzyme impacts on PMP and how a small X.

Cell wall -degrading enzymes enlarge the pore size of intervessel pit membranes in healthy and Xylella fastidiosa-infected grapevines. The effect of introducing trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid CDTA , oligogalacturonides, and polygalacturonic acid into stems on water flux via the xylem was also measured.

Mechanism of action of Spanish oregano, Chinese cinnamon, and savory essential oils against cell membranes and walls of Escherichia coli O H7 and Listeria monocytogenes. The mechanism of the antimicrobial action of Spanish oregano Corydothymus capitatus , Chinese cinnamon Cinnamomum cassia , and savory Satureja montana essential oils against cell membranes and walls of bacteria was studied by the measurement of the intracellular pH and ATP concentration, the release of cell constituents, and the electronic microscopy observations of the cells when these essential oils at their MICs were in contact with Escherichia coli O Treatment with these essential oils at their MICs affected the membrane integrity of bacteria and induced depletion of the intracellular ATP concentration.

Spanish oregano and savory essential oils, however, induced more depletion than Chinese cinnamon oil. An increase of the extracellular ATP concentration was observed only when Spanish oregano and savory oils were in contact with E.

Also, a significantly higher P cell constituent release was observed in the supernatant when E. Chinese cinnamon oil was more effective to reduce significantly the intracellular pH of E. H7, whereas Chinese cinnamon and Spanish oregano decreased more significantly the intracellular pH of L. Electronic microscopy observations revealed that the cell membrane of both treated bacteria was significantly damaged.

These results suggest that the cytoplasmic membrane is involved in the toxic action of essential oils. In chemical terms, wood is best defined as a three-dimensional biopolymer composite composed of an interconnected network of cellulose, hemicelluloses, and lignin with minor amounts of extractives and inorganics.

The major chemical component of a living tree is water, but on a dryweight basis, all wood cell walls consist mainly of sugar-based polymers carbohydrates, Bacterial Cell Wall Components. Bacterial cell -surface polysaccharides cells are surrounded by a variety of cell -surface structures that allow them to thrive in extreme environments.

Components of the cell envelope and extracellular matrix are responsible for providing the cells with structural support, mediating intercellular communication, allowing the cells to move or to adhere to surfaces, protecting the cells from attack by antibiotics or the immune system, and facilitating the uptake of nutrients.

Some of the most important cell wall components are polysaccharide structures. This review discusses the occurrence, structure, function, and biosynthesis of the most prevalent bacterial cell surface polysaccharides: The roles of these polysaccharides in medicine, both as drug targets and as therapeutic agents, are also described.

Isolation of plant cell wall proteins. The quality of a proteomic analysis of a cell compartment strongly depends on the reliability of the isolation procedure for the cell compartment of interest. Plant cell walls possess specific drawbacks: Three categories of CWP are distinguished: Two alternative protocols are decribed for cell wall proteomics: These protocols give very low levels of contamination by intracellular proteins. Their application should lead to a realistic view of the cell wall proteome at least for labile and weakly bound CWP extractable by salts.

Cell Wall Assembly in Fucus Zygotes. Fertilization triggers the assembly of a cell wall around the egg cell of three brown algae, Fucus vesiculosus, F. New polysaccharide polymers are continually being added to the cell wall during the first 24 hours of synchronous embryo development. This wall assembly involves the extracellular deposition of fibrillar material by cytoplasmic vesicles fusing with the plasma membrane. One hour after fertilization a fragmented wall can be isolated free of cytoplasm and contains equal amounts of cellulose and alginic acid with no fucose-containing polymers fucans present.

Birefringence of the wall caused by oriented cellulose microfibrils is not detected in all zygotes until 4 hours, at which time intact cell walls can be isolated that retain the shape of the zygote. These walls have a relatively low ratio of fucose to xylose and little sulfate when compared to walls from older embryos. When extracts of walls from 4-hour zygotes are subjected to cellulose acetate electrophoresis at pH 7, a single fucan F1 can be detected.

By 12 hours, purified cell walls are composed of fucans containing a relatively high ratio of fucose to xylose and high levels of sulfate, and contain a second fucan F2 which is electrophoretically distinct from F1.

F2 appears to be deposited in only a localized region of the wall , that which elongates to form the rhizoid cell. Throughout wall assembly, the polyuronide block co-polymer alginic acid did not significantly vary its mannuronic M to guluronic G acid ratio 0. From 6 to 24 hours of embryo development, the proportion of the major polysaccharide components found in purified walls is stable. During the extracellular assembly of this wall , the intracellular levels of the storage glucan laminaran.

Two bean cell wall proteins more abundant during water deficit are high in proline and interact with a plasma membrane protein. Two antigenically related glycoproteins, called p33 and p36, accumulate in the soluble fraction of the cell wall in response to water deficit in Phaseolus vulgaris.

In this report, we show that p33 and p36 are able to adhere to leaf protoplasts, and that they bind to plasma membrane PM vesicles in a divalent cation-dependent manner. Binding assays demonstrate that both proteins specifically bind to an 80 kDa PM protein. This binding is competed with a peptide that contains the RGD motif, as well as with fibronectin, which also includes this sequence, suggesting that the 80 kDa PM protein has an integrin-like function whose natural ligands are p33 and p This is the first case where a PM ligand for a higher plant cell wall protein has been identified.

Microsporidia are obligate intracellular parasites, and a derivative of fungi, which harbor a rigid spore wall to resist adverse environmental pressures. The spore wall protein, which is thought to be the first and direct protein interacting with the host cell , may play a key role in the process of microsporidia infection. The protein also has 6 heparin-binding motifs which are known to interact with extracellular glycosaminoglycans.

Syntenic analysis indicated that gene loci of Nbhswp11 are conserved and syntenic between Nosema bombycis and Nosema ceranae.

Nbhswp11 was transcribed throughout the entire life stages, and gradually increased during days, in a silkworm that was infected by N. Western blotting analysis displayed NbHSWP11 expressed in the total mature spore proteins and spore coat proteins.

Indirect immunofluorescence assay revealed NbHSWP11 located at the spore wall of mature spores and the spore coats. Furthermore, immune electron microscopy showed that NbHSWP11 localized in the cytoplasm of the sporont. Within the developmental process of N. However, most of NbHSWP11 distributes on the membraneous structures of the sporoblast and mature spore. In addition, using a host cell binding assay, native protein NbHSWP11 in the supernatant of total soluble mature spore proteins is shown to bind to the host cell BmE surface.

Finally, an antibody blocking assay showed that purified rabbit antibody of NbHSWP11 inhibits spore adherence and decreases the adherence rate of spores by Diffusion nearby elastic cell membranes. The physical approach of a small particle to the cell membrane represents the crucial step before active internalization and is governed by Brownian diffusion. Using a fully analytical theory, we show that the stretching and bending of cell membranes induces a long-lived subdiffusive behavior on the nearby particle.

Such behavior is qualitatively different from the normal diffusion in a bulk fluid or near a hard- wall. Moreover, we investigate the hydrodynamic interaction between two particles finding that the steady motion of two particles towards an elastic membrane possessing only shearing resistance leads to attractive interaction in contrast to the hard- wall case where the interaction is known to be repulsive.

Our analytical predictions are compared with boundary-integral simulations where an excellent agreement is obtained. The role of Lactobacillus cell wall components in the protection against pathogen infection in the gut is still largely unexplored.

We have previously shown that L. We have also demonstrated that L. In the present study, we investigated the role of L. Purified cell wall fragments CWF from L. Tight junction TJ and adherens junction AJ proteins were analyzed by immunofluorescence and Western blot.

Membrane permeability was determined by phenol red passage. Phosphorylated pNF-kB was measured by Western blot. The results indicate that the various components of L. Dynamics of cell wall structure in Saccharomyces cerevisiae.

The cell wall of Saccharomyces cerevisiae is an elastic structure that provides osmotic and physical protection and determines the shape of the cell. The inner layer of the wall is largely responsible for the mechanical strength of the wall and also provides the attachment sites for the proteins that form the outer layer of the wall. Here we find among others the sexual agglutinins and the flocculins.

The outer protein layer also limits the permeability of the cell wall , thus shielding the plasma membrane from attack by foreign enzymes and membrane -perturbing compounds. The main features of the molecular organization of the yeast cell wall are now known. Importantly, the molecular composition and organization of the cell wall may vary considerably. For example, the incorporation of many cell wall proteins is temporally and spatially controlled and depends strongly on environmental conditions.

Similarly, the formation of specific cell wall protein-polysaccharide complexes is strongly affected by external conditions. This points to a tight regulation of cell wall construction. Indeed, all five mitogen-activated protein kinase pathways in bakers' yeast affect the cell wall , and additional cell wall -related signaling routes have been identified. Finally, some potential targets for new antifungal compounds related to cell wall construction are discussed.

Composite fuel cell membranes. A bilayer or trilayer composite ion exchange membrane is described suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. Novel antihistamines for symptomatic treatment are aimed at the histamine H3-receptor. New adjuvants with toll-like receptor 4 activity or the application of the monoclonal anti-immunoglobulin E antibody, omalizumab, are supposed to enhance conventional immunotherapy.

An approach targeting toll-like receptor 9 by. Full Text Available The European Union handed over the regulation of common ragweed Ambrosia artemisiifolia to the member states. Austrian administration started to ask for control measures, i. Any sustainable control measure must focus on the reduction of seeds produced by the annual ragweed.

Seed bank dimension of ragweed turned out to be a good evaluation tool for any control measure. To evaluate the importance of different spreading mechanisms of dispersal, a need for serious figures can be stated. Based on our seed trap experiments and comparable slip stream experiments by German botanists, the efficiency of vehicles in spreading ragweed over long distances was low.

However, machines used by road services cutter, moulder turned out to spread thousands of seeds. Besides, there is serious indication that trucking agricultural food and seeds over long distances is relevant for ragweed seed dispersal. Dispersal of thousands of ragweed seeds from contaminated agricultural fields to fields not yet infested is caused by harvesters and other agricultural machines.

Regulations to reduce the ragweed load in traded agricultural goods are to be implemented in future. Small populations of ragweed should be simply uprooted and composted as long as they bear no flowers. Various possibilities are known for control of common ragweed in agricultural fields with mechanical and chemical methods. Limits are set in sunflowers because sunflower and ragweed are botanically related. The legal obligation of reporting and control — introduced in Switzerland a couple of years ago — allowed the development of specific distribution maps and enhanced the quality of control measures.

Facts and figures from the Canton of Geneva prove that the ragweed invasion has been stopped, but the species is not eradicated. The results of Geneva represent the results of good ragweed control in the whole country.

Beside agriculture, traffic infrastructure, building sites, gravel pits and urban park and garden areas are sensible to ragweed invasion. The responsibility of individuals helps to improve control efficiency even if financial funds are small. A sustainable control success depends on the efficiency to hamper seed production. The reduction of pollen quantity in the air in a long term is part of the earnings for the control effort.

Actually, the publicity of common ragweed is fed by specialist information and its distribution in the media. It would be an interesting task to develop in our fast moving era an awareness level comparable to that of the stinging nettle.

Effect of heavy metals on seed germination and seedling growth of common ragweed and roadside ground cover legumes. It creates empty niches vulnerable to weed establishment such as common ragweed Ambrosia artemisiifolia. We hypothesized that heavy metal stresses may drive such species shifts along roadside edges. A growth chamber experiment was conducted to assess effects of metals Zn, Pb, Ni, Cu, and Cd on germination and seedling behaviors of roadside weed A.

All metals inhibited T. Low levels of Pb and Ni promoted germination initiation of A. Metal additions hindered seedling growth of all test species, and the inhibitory effect on the belowground growth was greater than on the aboveground growth. Seedling mortality was lowest in A. In conclusion, the successful establishment of A. The findings also revealed that L. Full Text Available Identifying the sensitive habitats with high invasibility is critical for management of biological invasion. Ragweed Ambrosia artemisiifolia Linn.

The experiment took ragweek as a model invader to reveal the community invisibility of different habitats. The results suggested that the presence of native species had strong negative effects on the performance of the invader species. The presence of native species occupied the niche space and left few empty niches for the colonization of the invaders.

The results revealed that planting native species in bare soils, and maintaining the native communities with high diversity, was effective strategies to control the invasion of exotic species. The present situation of the plant was analyzed in Qinhuangdao region, and the new campus was taken as an example to inves-tigate the effects of human activity disturbance on A.

The invasiveness of A. In present, the plant was a community construction species in this region, and showed no invasion. The investigated results showed that A. However, in the habitat disturbed by human activities, the plant had relatively high advantage. Therefore, excessive human activity disturbance should be prevented to control the invasive plant, by which to protect the local ecological environment.

Ragweed subpollen particles of respirable size activate human dendritic cells. Full Text Available Ragweed Ambrosia artemisiifolia pollen grains, which are generally considered too large to reach the lower respiratory tract, release subpollen particles SPPs of respirable size upon hydration. In this study, we examined whether exposure to SPPs initiates the activation of human monocyte-derived dendritic cells moDCs.

Collectively, our data suggest that inhaled ragweed SPPs are fully capable of activating dendritic cells DCs in the airways and SPPs' NAD PH oxidase activity is involved in initiation of adaptive immune responses against innocuous pollen proteins. Characterizing restriction enzyme-associated loci in historic ragweed Ambrosia artemisiifolia voucher specimens using custom-designed RNA probes. Population genetic studies of non-model organisms frequently employ reduced representation library RRL methodologies, many of which rely on protocols in which genomic DNA is digested by one or more restriction enzymes.

However, because high molecular weight DNA is recommended for these protocol Ambrosia is a kind of invasive alien weed, whose invasion not only threatens native biodiversity and ecosystems, but also causes considerable economic loss. In order to control the damage of Ambrosia effectively, on the basis of introducing mechanical, chemical and biological control methods, the insufficiencies of them were clarified and an integrated control measure was proposed.

Exotic plant invasion presents a serious threat to native ecosystem structure and function. Little is known about the role of soil microbial communities in facilitating or resisting the spread of invasive plants into native communities.

The purpose of this research is to understand how the invasive annual plantAmbrosiaartemisiifoliaL. The soil characteristics of different areas invaded by A. Greenhouse experiments were designed to assess the effect ofA. The results showed that the soil organic C content was the highest in heavily invaded sites, the lowest in native plant sites, and intermediate in newly invaded sites.

Soil available N, P and K concentrations in heavily invaded site were 2. Soil pH decreased asA. The soil microbial community structure was clearly separated in the three types of sites, andA. Soil biota of invaded sites inhibits growth of co-occurring plants Galinsoga parvilfora Cav. Results of the present study indicated thatA. Northern ragweed ecotypes flower earlier and longer in response to elevated CO2: Significant changes in plant phenology and flower production are predicted over the next century, but we know relatively little about geographic patterns of this response in many species, even those that potentially impact human wellbeing.

We tested for variation in flowering responses of the allergenic plant, Ambrosia artemisiifolia common ragweed. We hypothesized that northern ecotypes adapted to shorter growing seasons would flower earlier than their southern counterparts, and thus disproportionately allocate carbon gains from CO2 to reproduction.

As predicted, latitude of origin and carbon dioxide level significantly influenced the timing and magnitude of flowering. Reproductive onset occurred earlier with increasing latitude, with concurrent increases in the number of flowers produced. Elevated carbon dioxide resulted in earlier reproductive onset in all ecotypes, which was significantly more pronounced in the northern populations.

We interpret our findings as evidence for ecotypic variation in ragweed flowering time, as well in responses to CO2. Thus, the ecological and human health implications of common ragweed 's response to global change are likely to depend on latitude. We conclude that increased flower production, duration, and possibly pollen output, can be expected in Northeastern United States with rising levels of CO2.

The effects are likely, however, to be most significant in northern parts of the region. The invasive alien species Ambrosia artemisiifolia common or short ragweed is increasing its range in Europe. In the UK and the Netherlands, airborne concentrations of Ambrosia pollen are usually low. However, more than 30 Ambrosia pollen grains per cubic metre of air above the level capable to trigger allergic symptoms were recorded in Leicester UK and Leiden NL on 4 and 5 September The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the episode could be the result of long distance transport, to identify the potential sources of these pollen grains and to describe the conditions that facilitated this possible long distance transport.

Airborne Ambrosia pollen data were collected at 10 sites in Europe. Back trajectories calculated at Leicester and Leiden show that higher altitude air masses m originated from source areas on the Pannonian Plain and Ukraine. The study indicates that the Ambrosia pollen grains recorded during the episode in Leicester and Leiden were probably not produced by local sources but transported long distances from potential source regions in east Europe, i.

Ambrosia airborne pollen concentration modelling and evaluation over Europe. Native from North America, Ambrosia artemisiifolia L. Common Ragweed is an invasive annual weed introduced in Europe in the mid-nineteenth century. It has a very high spreading potential throughout Europe and releases very allergenic pollen leading to health problems for sensitive persons. Because of its health effects, it is necessary to develop modelling tools to be able to forecast ambrosia air pollen concentration and to inform allergy populations of allergenic threshold exceedance.

To calculate and predict airborne concentrations of ambrosia pollen, a chain of models has been built. The detailed methodology, formulations and input data will be presented. A set of simulations has been performed to simulate airborne concentrations of pollens over long time periods on a large European domain. Hindcast simulations - driven by ERA-Interim re-analyses are designed to best simulate past periods airborne pollens. The modelled pollen concentrations are calibrated with observations and validated against additional observations.

Then, year long historical simulations - are carried out using calibrated ambrosia density distribution and climate model-driven weather in order to serve as a control simulation for future scenarios. By comparison with multi-annual observed daily pollen counts we have shown that the model captures well the gross features of the pollen.

Modelling the introduction and spread of non-native species: Biological invasions are a major driver of global change, for which models can attribute causes, assess impacts and guide management. However, invasion models typically focus on spread from known introduction points or non-native distributions and ignore the transport processes by which species arrive. Here, we developed a simulation model to understand and describe plant invasion at a continental scale, integrating repeated transport through trade pathways, unintentional release events and the population dynamics and local anthropogenic dispersal that drive subsequent spread.

We used the model to simulate the invasion of Europe by common ragweed Ambrosia artemisiifolia , a globally invasive plant that causes serious harm as an aeroallergen and crop weed.

Simulations starting in accurately reproduced ragweed 's current distribution, including the presence of records in climatically unsuitable areas as a result of repeated introduction.

Furthermore, the model outputs were strongly correlated with spatial and temporal patterns of ragweed pollen concentrations, which are fully independent of the calibration data. The model suggests that recent trends for warmer summers and increased volumes of international trade have accelerated the ragweed invasion. For the latter, long distance dispersal because of trade within the invaded continent is highlighted as a key invasion process, in addition to import from the native range. Biosecurity simulations, whereby transport through trade pathways is halted, showed that effective control is only achieved by early action targeting all relevant pathways.

We conclude that invasion models would benefit from integrating introduction processes transport and release with spread dynamics, to better represent propagule pressure from native sources as well as mechanisms for long-distance dispersal within invaded continents. Ultimately, such integration may facilitate better prediction of spatial and temporal variation in invasion. Ragweed pollen production and dispersion modelling within a regional climate system, calibration and application over Europe.

Its pollen can be transported over large distances and has been recognized as a significant cause of hay fever and asthma D'Amato et al. To simulate production and dispersion of common ragweed pollen, we implement a pollen emission and transport module in the Regional Climate Model RegCM version 4 using the framework of the Community Land Model CLM version 4.

In this online approach pollen emissions are calculated based on the modelling of plant distribution, pollen production, species-specific phenology, flowering probability, and flux response to meteorological conditions. A pollen tracer model is used to describe pollen advective transport, turbulent mixing, dry and wet deposition. The model is then applied and evaluated on a European domain for the period To reduce the large uncertainties notably due to the lack of information on ragweed density distribution, a calibration based on airborne pollen observations is used.

Accordingly a cross validation is conducted and shows reasonable error and sensitivity of the calibration. Resulting simulations show that the model captures the gross features of the pollen concentrations found in Europe, and reproduce reasonably both the spatial and temporal patterns of flowering season and associated pollen concentrations measured over Europe.

The model can explain The correlation between simulated and observed daily concentrations time series reaches 0. Statistical scores show that the model performs better over the central Europe source region where pollen loads are larger and the model is better constrained. From these simulations health risks associated to common ragweed pollen. The airborne ragweed pollen spectrum was investigated in the air of Ankara, Turkey for aperiod of ten years using a Burkard seven-day volumetric recording trap.

In our study period,long distance transported Ambrosia pollen has been registered. Daily pollen levels varied from low to highin Burge's system. In last three years, the pollen concentration of Ambrosia showed a clear increasingtendency.

Our results prove that ragweed pollen may be an important threat for ragweed sensitive patientsin Ankara city in near future. Lifescience Database Archive English. Full Text Available c Spatial and temporal variations in airborne Ambrosia pollen in Europe.

The goal of the present study is to provide a baseline for spatial and temporal variations in airborne Ambrosia pollen in Europe that can be used for the management and evaluation of this noxious plant.

The study covers the full range of Ambrosia artemisiifolia L. Airborne Ambrosia pollen data for the principal flowering period of Ambrosia August-September recorded during a year period were obtained from monitoring sites. The mean sum of daily average airborne Ambrosia pollen and the number of days that Ambrosia pollen was recorded in the air were analysed. The mean and standard deviation SD were calculated regardless of the number of years included in the study period, while trends are based on those time series with 8 or more years of data.

The direction of any trends varied locally and reflected changes in sources of the pollen, either in size or in distance from the monitoring station. Pollen monitoring is important for providing an early warning of the expansion of this invasive and noxious plant.

The extraction of exotic plant ragweed Ambrosia artemisiifolia L. It can prevent the extraction of ragweed from inactivation,which could be easily caused by external condition such as illumination and temperature.

The microcapsule technique can improve the property of extraction. The results showed that the morphology of microcapsules was regular and integrated observed under scanning electron microscope SEM.

Moreover,the core material was coated with shell material observed by the infrared spectrum analysis with Fourier transform infrared spectroscopy FTIR. The association efficiency and loading capacity of the microcapsules determined by ultraviolet spectrophotometer were The medium diameter was And the results of thermogravimetric analysis TGA demonstrated that the thermal stability of the microcapsules was superior to the core material.

Consequently,the microcapsules with the extraction can avoid the unstable defect of the natural extraction. In addition,the activity was also lengthened by this technique. The occurrence of Ambrosia pollen in the atmosphere of Northwest Turkey: Ambrosia pollen was first reported as an important allergen in North America at the end of the nineteenth century, and many European countries have recently reported its increasing significance for pollen allergy.

The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the studied period could be the result of long-distance transport LDT and to identify the potential sources of Ambrosia pollen grains. The study investigates Ambrosia pollen episodes during the peak term of six yearly periods between and by examining source regions in Ambrosia pollen in Bursa, Turkey.

A volumetric trap was used for collecting the pollen samples, and the back-trajectory model was used to identify a potential source of atmospheric Ambrosia pollen. The days when pollen levels exceeded 30 P m-3 were computed, and clusters were shown on the figures.

The study indicates that the Ambrosia pollen grains recorded during the episode in Bursa were not produced by local sources but transported long distances from potential source regions around the Azov Sea in Russia and Ukraine, Black Sea region of Turkey, Romania, and Bulgaria.

Note that atmospheric concentrations of Ambrosia pollen exceeded the clinical threshold during 28 days during the investigation period. Taking into consideration the high allergenicity of Ambrosia pollen, the present findings suggest that the number of ragweed -sensitized individuals might increase in the near future in the region.

Full Text Available From a medical perspective, introduction and spread of ragweed in Germany are a disaster. The pollen of the species trigger allergic rhinitis and conjunctivitis that often lead to allergies against food items like celery or spices. In some cases this can lead to allergic asthma that at first appears during the ragweed pollen season in September and October, but can later prevail during the whole year.

In addition, touching the plant can result in contact dermatitis. From a medical point of view, halting the spread of ragweed is important and necessary.

Analysis of high allergenicity airborne pollen dispersion: The appearance of ragweed pollen in the air became more frequent in northerly countries. Attention of allergologists and aerobiologists in these countries is focused on the phenomenon that Ambrosia plants found relatively sporadic but the amount of pollen is high in particular days. Over the latter decade, a matter of particular concern has been Ambrosia pollen, whose appearance in the air is determined by the plants dispersing it and meteorological processes that alter pollen release, dissemination, transport or deposition on surfaces.

Pollen data used in this study were collected in three pollen-trapping sites in Lithuania. The data corresponding to years of pollen monitoring were documented graphically and evaluated statistically. Analysis of the pollen data suggests that although the number of ragweed plants identified has not increased over the latter decade, the total pollen count has been on the increase during the recent period. The highest atmospheric pollen load is established on the last days of August and first days of September.

We have established a regularity exhibiting an increase in ragweed pollen count conditioned by south-eastern winds in Lithuania. The ex-periment took ragweek as a model invader to reveal the community invisibility of different habitats. The results revealed that planting native species in bare soils, and maintaining the native communities.

Plants remember past weather: After extreme dry wet summers or years, pollen production of different taxa may decrease increase substantially. Accordingly, studying effects of current and past meteorological conditions on current pollen concentrations for different taxa have of major importance.

The purpose of this study is separating the weight of current and past weather conditions influencing current pollen productions of three taxa. Two procedures, namely multiple correlations and factor analysis with special transformation are used.

The year data sets include daily pollen counts of Ambrosia ragweed , Poaceae grasses and Populus poplar , as well as daily values of four climate variables temperature, relative humidity, global solar flux and precipitation. Multiple correlations of daily pollen counts with simultaneous values of daily meteorological variables do not show annual course for Ambrosia , but do show definite trends for Populus and Poaceae. Results received using the two methods revealed characteristic similarities.

For all the three taxa, the continental rainfall peak and additional local showers in the growing season can strengthen the weight of the current meteorological elements. However, due to the precipitation, big amount of water can be stored in the soil contributing to the effect of the past climate elements during dry periods.

Higher climate sensitivity especially water sensitivity of the herbaceous taxa Ambrosia and Poaceae can be definitely established compared to the arboreal Populus.

Separation of the weight of the current and past weather conditions for different taxa involves practical importance both for health care and agricultural production. Field and greenhouse experiments were conducted during and at Stoneville, MS to determine control of ragweed parthenium with several preemergence PRE and postemergence POST herbicides registered for use in corn, cotton, peanut, rice, and soybean. Change in Ragweed Pollen Season, Environmental Protection Agency — This figure shows how the length of ragweed pollen season changed at 11 locations in the central United States and Canada between and Ambrosia beetles are being increasingly recognized as significant pests of field-grown ornamental nursery stock.

Two species are especially problematic in ornamental nurseries, namely the black stem borer, Xylosandrus germanus, and the granulate ambrosia beetle, Xylosandrus crassiusculus. Economic analysis of preventing introduction of ragweed in Denmark. Ragweed is an Invasive Alien Species natively growing in North America which is at risk of being introduced in Denmark thru import of bird seeds.

The plant produces a high amount of pollen which causes allergy and asthma and is considered a very potent allergy source. It is estimated that An inordinate fondness for Fusarium: Phylogenetic diversity of fusaria cultivated by Euwallacea ambrosia beetles on avocado and other plant hosts. Ambrosia beetle fungiculture represents one of the most ecologically and evolutionarily successful symbioses. Here we document the evolution of a clade within Fusarium associated with ambrosia beetles in the genus Euwallacea Coleoptera: Is ragweed pollen allergenicity governed by environmental conditions during plant growth and flowering?

However, how genotype and environment contribute to ragweed pollen allergenicity has still to be established. To throw some light on the factors governing allergenicity, in this work ragweed plants from three Regions Canada, France, Italy were grown in both controlled constant and standard environmental conditions seasonal changes in temperature, relative humidity and light.

Pollen from single plants was characterized for its allergenic potency and for the underlying regulation mechanisms by studying the qualitative and quantitative variations of the main isoforms of the major ragweed allergen Amb a 1. Results showed a statistically higher variability in allergenicity of pollen from standard conditions than from controlled conditions growing plants.

This variability was due to differences among single plants, regardless of their origin, and was not ascribed to differences in the expression and IgE reactivity of individual Amb a 1 isoforms but rather to quantitative differences involving all the studied isoforms.

It suggests that the allergenic potency of ragweed pollen and thus the severity of ragweed pollinosis mainly depends on environmental conditions during plant growth and flowering, which regulate the total Amb a 1 content. Effects of photoperiod and temperature on reproductive diapause in Ophraella communa Coleoptera: Chrysomelidae , a potential biocontrol agent against Ambrosia artemisiifolia.

To investigate the seasonal adaptation strategies of Ophraella communa to new habitats,the effects and regulation mechanisms of photoperiod and temperature on the reproductive diapause in a population collected from Changsha,Hunan were examined.

Adults showed obvious reproductive diapause,which was regulated by photoperiod and temperature. The pre-oviposition period was significantly prolonged when the pupae and adults were transferred from long-days to short-days,but the day length influence was not obvious when they were transferred only in the adult stage. However,the fecundity dropped greatly no matter whether the photoperiod shifted to short-days only in the adult stage or whether the shift occurred in both the pupal and adult stage.

The fecundity was extremely low when photoperiod shifted from long-days to short-days in both pupal and adult stages. This was an indication that the pupal and adult stages were the photoperiod-sensitive stage for adult reproductive diapause.

This was especially true for the photoperiod in the pupal stage,which has a distinctly significant regulative effect on reproductive diapause. Additionally,this article also addresses the reason for different photoperiodic response patterns in reproductive diapause induction between the Changsha strain and the Tsukuba strain Japan of O.

Ragweed in France is a rather recent pollen which causes strong allergies on the populations concerned. This pollen, mainly located in the area Rhone-Alpes, extend more and more on totality of France.

Indeed, the pollinic data highlight the presence of ragweed on all the territory with very low, as for Brittany, to several hundreds grains in the area of Rhone-Alpes.

So four towns of this area have followed closely the extend of this pollen during the year through five pollen-traps 2 for the town of Lyon. The trap of Lyon I Gerland made it possible to follow temporal the extend of ragweed from to and the increase of the number of grains as that of the number of days with a significant allergic risk.

The study shows also the differences in quantity of pollens, the differences between the daily allergic risks of the five sites, as well as the differences, between the cities, of the number of days when the allergic risk is significant. It is necessary that pollen of ragweed can be followed closely because of its strong allergenic capacity, in the area of Rhone-Alpes, where the plant prevails mainly, but also on the totality of the own territory, this to supervise its evolution and the speed of proliferation of the plant.

Chemical ecology and lure development for redbay ambrosia beetle. The exotic redbay ambrosia beetle, Xyleborus glabratus Eichhoff, has become a serious invasive pest in the U. Female beetles are the primary vectors of a pathogenic fungus Raffaelea lauricola that causes laurel wilt. This lethal vascular dise Ambrosia beetles associated with laurel wilt of avocado. Redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-boring pest first detected in near Savannah, Georgia.

Laurel wilt has since spr The invasive redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-boring pest first detected in the U. Redbay Ambrosia Beetle xyleborus glabratus eichoff coleoptera: The redbay ambrosia beetle, Xyleborus glabratus Eichoff, and its associated fungus Raffaelea lauricola T.

Together, they cause a vascular wilt disease that is highly destructive to some species in the Lauraceae Fraedrich et al. Xyleborus glabratus is a member of the Chemical ecology of the redbay ambrosia beetle Xyleborus glabratus. The redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-boring pest first detected in the U.

Ethanol injection of ornamental trees facilitates testing insecticide efficacy against ambrosia beetles Coleoptera: Exotic ambrosia beetles are damaging pests in ornamental tree nurseries in North America. The species Xylosandrus crassiusculus Motshulsky and Xylosandrus germanus Blandford are especially problematic. Management of these pests relies on preventive treatments of insecticides.

However, field tests of recommended materials on nursery trees have been limited because of unreliable attacks by ambrosia beetles on experimental trees. Ethanol-injection of trees was used to induce colonization by ambrosia beetles to evaluate insecticides and botanical formulations for preventing attacks by ambrosia beetles. Experiments were conducted in Ohio, Tennessee, and Virginia. Experimental trees injected with ethanol had more attacks by ambrosia beetles than uninjected control trees in all but one experiment.

Xylosandrus crassiusculus and X. In most experiments, attack rates declined 8 d after ethanol-injection. Ethanol-injection induced sufficient pressure from ambrosia beetles to evaluate the efficacy of insecticides for preventing attacks. Trunk sprays of permethrin suppressed cumulative total attacks by ambrosia beetles in most tests. Trunk sprays of the botanical formulations Armorex and Veggie Pharm suppressed cumulative total attacks in Ohio. The bifenthrin product Onyx suppressed establishment of X.

Substrate drenches and trunk sprays of neonicotinoids, or trunk sprays of anthranilic diamides or tolfenpyrad were not effective. Ethanol-injection is effective for inducing attacks and ensuring pressure by ambrosia beetles for testing insecticide efficacy on ornamental trees. Chemical ecology and serendipity: Developing attractants for Florida ambrosia beetle pests.

Two exotic ambrosia beetles have become established in southern Florida: Both pests vector pathogenic fungal symbionts; the former for laurel wilt and the latter for Fusarium dieback d Symbiont diversification in ambrosia beetles: Diversity of fungi associated with exotic scolytine beetles.

In virtually every forest habitat, ambrosia beetles Coleoptera: Scolytinae, Platypodinae plant and maintain symbiotic fungus gardens inside dead or dying wood. Some introduced ambrosia beetles aggressively attack live trees and can damage tree crops, lumber, and native woody plant t In children allergic to ragweed pollen, nasal inflammation is not influenced by monosensitization or polysensitization.

In patients polysensitized to pollen allergens, the priming effect, by which the sensitivity of the nasal mucosa to an allergen is increased by the previous exposure to another allergen, is a known phenomenon. This study was aimed at evaluating the degree of nasal inflammation, assessed by nasal cytology, in children with allergic rhinitis AR from ragweed pollen according to being monosensitized or polysensitized.

The study included 47 children. Of them, 24 suffered from AR caused by sensitization to grass pollen and ragweed pollen group A and 23 were sensitized only to ragweed pollen group B.

In all patients, the severity of AR was assessed according to the Allergic Rhinitis and Its Impact on Asthma guidelines, and comorbidities were also evaluated. In group A, No significant difference was detected in the number of the considered comorbidities between the two groups.

This document assesses and compares the environmental impacts of various alternatives for remedial action at the Ambrosia Lake uranium mill tailings site located near Ambrosia Lake, New Mexico.

The designated site covers acres and contains acres of tailings and some of the original mill structures.

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Cellular andExtracellular SiderophoresofAspergillus based onthis dependency to reexamine the extracellular siderophores ofthese found that exposure of conidia. Cellular and extrace | Aspergillus nidulans and Penicillium chrysogenum produce specific cellular siderophores in addition to the well-known siderophores of the. Evaluation of Mold Contamination in a. exposure to a mycotoxin. What NIOSH Found Aspergillus/Penicillium.

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Aspergillosis & Moldy Indoor Environments