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[diversity of actinomycetes in wuling mountain].to isolate new actinomycetes for discovering compounds of pharmaceutical importance.200818837376
physico-chemical and microbial characteristics of the coral reef environment of the gulf of mannar marine biosphere reserve, india.investigation on physico-chemical parameters and bacteial characteristics of the coral reef environs of the gulf of mannar biosphere reserve was studied. the study found the influence of different physico-chemical parameters on one another and also on the distribution of the total heterotrophic bacteria (thb) in the coral reef areas. nutrients exhibited considerable seasonal and spatial variations with influence on the bacterial population. coral reef areas recorded higher bacterial population d ...200818831378
expeditious chemoenzymatic synthesis of homogeneous n-glycoproteins carrying defined oligosaccharide ligands.an efficient chemoenzymatic method for the construction of homogeneous n-glycoproteins was described that explores the transglycosylation activity of the endo-beta-n-acetylglucosaminidase from arthrobacter protophormiae (endo-a) with synthetic sugar oxazolines as the donor substrates. first, an array of large oligosaccharide oxazolines were synthesized and evaluated as substrates for the endo-a-catalyzed transglycosylation by use of ribonuclease b as a model system. the experimental results show ...200818803385
cell surface o-glycans limit staphylococcus aureus adherence to corneal epithelial cells.the mucin-rich environment of the intact corneal epithelium is thought to contribute to the prevention of staphylococcus aureus infection. this study examined whether o-glycans, which constitute the majority of the mucin mass of epithelial cell glycocalyces, prevented bacterial adhesion and growth. abrogation of mucin o glycosylation using the chemical primer benzyl-alpha-galnac resulted in increased adherence of parental strain rn6390 to apical human corneal-limbal epithelial (hcle) cells and t ...200818794288
heterologous expression and characterization of choline oxidase from the soil bacterium arthrobacter nicotianae.in the course of a microbial screening of soil samples for new oxidases, different enrichment strategies were carried out. with choline as the only carbon source, a microorganism was isolated and identified as arthrobacter nicotianae. from this strain, a gene coding for a choline oxidase was isolated from chromosomal dna. this gene named coda was cloned in escherichia coli bl21-gold and the protein (an_coda) heterologously overexpressed as a soluble intracellular protein of 59.1 kda. basic bioch ...200918787818
coupled biocatalysts applied to the synthesis of nucleosides.biocatalytic procedures offer a good alternative to the chemical synthesis of nucleosides since biocatalyzed reactions are regio- and stereoselective and afford reduced by-products contents. among them, enzymatic transglycosylation between a pyrimidine nucleoside and a purine base catalyzed by nucleoside phosphorylases or microorganisms that contain them, has attracted considerable attention. in addition, the combination to other enzymatic steps has been explored. in this work we investigate the ...200818776493
[microbial community of freshwater sponges in lake bań≠kal].the microbial community of baikal sponges has been studied in five species belonging to the genera swartschewskia, baicalospongia, and lubomirskia of the endemic family lubomirskiidae. the results show that the total numbers of bacteria and bacterioplankton production have an effect on the growth of l. baicalensis body. bacteria of the genera pseudomonas, bacillus, micrococcus, sarcina, flavobacterium, arthrobacter, and acinetobacter living in the sponges are representatives of the baikal bacter ...200818771026
application of 16s rdna-dgge and plate culture to characterization of bacterial communities associated with the sawfly, acantholyda erythrocephala (hymenoptera, pamphiliidae).culture-based analysis was employed in parallel with pcr amplification of 16s rdna, coupled with denaturing gradient gel electrophoresis (dgge), to profile bacterial species associated with different developmental stages of the pine false webworm (pfw), acantholyda erythrocephala, a sawfly pest responsible for incidents of severe defoliation in commercially important tree plantations in north america. culture-based analysis revealed that pseudomonas spp. along with bacillus sphaericus and arthro ...200818769850
chromium (vi) reduction in activated sludge bacteria exposed to high chromium loading: brits culture (south africa).a mixed-culture of bacteria collected from a wastewater treatment plant in brits, north-west province (south africa) biocatalytically reduced cr(vi) at much higher concentrations than previously observed in cultures isolated in north america. cr(vi) reduction rate up to 8 times higher than the rate in previous cultures was achieved by the brits culture under aerobic conditions. near complete cr(vi) reduction was observed in batches under initial concentrations up to 200mg cr(vi)/l after incubati ...200818760438
cold adaptation of enzyme reaction rates.a major issue for organisms living at extreme temperatures is to preserve both stability and activity of their enzymes. cold-adapted enzymes generally have a reduced thermal stability, to counteract freezing, and show a lower enthalpy and a more negative entropy of activation compared to mesophilic and thermophilic homologues. such a balance of thermodynamic activation parameters can make the reaction rate decrease more linearly, rather than exponentially, as the temperature is lowered, but the ...200818759500
genome sequence of the fish pathogen renibacterium salmoninarum suggests reductive evolution away from an environmental arthrobacter ancestor.renibacterium salmoninarum is the causative agent of bacterial kidney disease and a significant threat to healthy and sustainable production of salmonid fish worldwide. this pathogen is difficult to culture in vitro, genetic manipulation is challenging, and current therapies and preventative strategies are only marginally effective in preventing disease. the complete genome of r. salmoninarum atcc 33209 was sequenced and shown to be a 3,155,250-bp circular chromosome that is predicted to contain ...200818723615
recovery of choline oxidase activity by in vitro recombination of individual segments.initial attempts to express a choline oxidase from arthrobacter pascens (apcho-syn) in escherichia coli starting from a synthetic gene only led to inactive protein. however, activity was regained by the systematic exchange of individual segments of the gene with segments from a choline oxidase-encoding gene from arthrobacter globiformis yielding a functional chimeric enzyme. next, a sequence alignment of the exchanged segment with other choline oxidases revealed a mutation in the apcho-syn, show ...200818704397
chromium (vi) reduction in activated sludge bacteria exposed to high chromium loading.a mixed-culture of bacteria collected from a wastewater treatment plant in brits, north-west province (south africa) biocatalytically reduced cr(vi) at much higher concentrations than previously observed in cultures isolated in north america. complete cr(vi) reduction in aerobic cultures was achieved at a high concentration of 200 mg/l after incubation for only 65 hours. under anaerobic conditions up to 150 mg, cr(vi)/l was completely removed after incubating for 130 to 155 hours, still higher t ...200818701792
a refinery sludge deposition site: presence of nahh and alkj genes and crude oil biodegradation ability of bacterial isolates.204 bacterial isolates from four greek refinery sludge deposition sites were investigated for the presence of nahh and alkj genes encoding key enzymes of both aromatic and aliphatic hydrocarbon degradation pathways by pcr and dna hybridisation. members of pseudomonas, acinetobacter, bacillus, rhodococcus and arthrobacter play important role in bioremediation processes in sandy/loam soil contaminated with oil and nahh and alkj genes were present in the 73% of the isolates. consortia of bacterial ...200818688575
the screening, characterization, and use of omega-laurolactam hydrolase: a new enzymatic synthesis of 12-aminolauric acid.several omega-laurolactam degrading microorganisms were isolated from soil samples. these strains were capable of growing in a medium containing omega-laurolactam as sole source of carbon and nitrogen. among them, five strains (t7, t31, u124, u224, and u238) were identified as cupriavidus sp. t7, acidovorax sp. t31, cupriavidus sp. u124, rhodococcus sp. u224, and sphingomonas sp. u238, respectively. the omega-laurolactam hydrolyzing enzyme from rhodococcus sp. u224 was purified to homogeneity, a ...200818685217
[catabolite repression of xylose isomerase synthesis in arthrobacter ureafaciens].the effect of a specific substrate as well as other carbon sources on the biosynthesis of xylose isomerase in the actinobacterium arthrobacter ureafaciens bim b-6 has been studied. it was established that xylose and its structural analogue xylite induced the production of the enzyme by bacterial cells. the inducing effect peaked at a concentration of specific substrates of 0.025% (as carbon) and then remained unchanged irrespective of the substrate amount. it has been shown that the synthesis of ...200818683646
enhanced glycosylation with mutants of endohexosaminidase a (endo a). 200818677737
corynebacterium ilicis is typified by icmp 2608 =icpb ci144, arthrobacter ilicis is typified by dsm 20138 =atcc 14264 =ncppb 1228 and the two are not homotypic synonyms, and clarification of the authorship of these two species. opinion 87.the judicial commission rules that the name corynebacterium ilicis mandel et al. 1961 is represented by the type strain icmp 2608 =icpb ci144 and is reported to be a plant-pathogenic species. arthrobacter ilicis is represented by the type strain dsm 20138 =atcc 14264 =ncppb 1228 and is not a homotypic synonym of corynebacterium ilicis mandel et al. 1961, and is reported not to be a plant pathogen. the authorship is to be cited as arthrobacter ilicis collins et al. 1982 and typification and the d ...200818676493
arthrobacter defluvii sp. nov., 4-chlorophenol-degrading bacteria isolated from sewage.two 4-chlorophenol-degrading bacteria, strains 4c1-at and 4c1-b, were isolated from sewage flowing into geumho river near the daegu industrial complex in korea. cells of the strains were gram-positive and non-motile, displayed a rod-coccus life cycle and formed creamy white colonies on r2a agar or peptone-carbohydrate agar. the strains had chemotaxonomic markers that were consistent with classification in the genus arthrobacter, i.e. mk-9(h2) as the major menaquinone, iso- and anteiso-branched c ...200818676480
different substrate specificities of two triazine hydrolases (trzns) from nocardioides species.nocardioides sp. strain mtd22 degraded atrazine, ametryn and atraton, as did arthrobacter aurescens strain tc1 and nocardioides sp. strain c190. these strains contain trzn, a gene coding for trzn, triazine hydrolase showing a broad substrate range. however, nocardioides sp. strain an3 degraded only atrazine despite containing trzn. these differences in s-triazine degradation are presumed to be due to differences in the amino acid sequences of trzns. consequently, 1371 nucleotides of the trzn cod ...200818671800
[glucose isomerase activity in suspension of arthrobacter nicotianae cells and adsorption immobilization of the microorganisms on inorganic carriers].kinetics of monosaccharide isomerization has been studied in suspensions of intact, non-growing arthrobacter nicotianae cells. under the conditions of the study, glucose and fructose were isomerized at the same maximum rate of 700 micromol/min per 1 g dried cells, which increased with temperature (the dependence was linear at 60-80 degrees c). the proposed means of adsorption immobilization of a. nicotianae cells involve inorganic carriers differing in macrostructure, chemical nature, and surfac ...200818669262
identities of arthrobacter spp. and arthrobacter-like bacteria encountered in human clinical specimens.after the initial description of arthrobacter spp. isolated from clinical specimens in the mid-1990s, very few further reports on arthrobacter spp. have appeared in the clinical microbiology literature. the aim of the present study was to elucidate the distribution of arthrobacter spp. and arthrobacter-like bacteria encountered in clinical specimens by studying 50 consecutively isolated or received strains of large-colony-forming, whiteish-grayish, non-cheese-like-smelling, nonfermentative gram- ...200818650355
structures of arthrobacter globiformis urate oxidase-ligand complexes.the enzyme urate oxidase catalyzes the conversion of uric acid to 5-hydroxyisourate, one of the steps in the ureide pathway. arthrobacter globiformis urate oxidase (aguox) was crystallized and structures of crystals soaked in the substrate uric acid, the inhibitor 8-azaxanthin and allantoin have been determined at 1.9-2.2 a resolution. the biological unit is a homotetramer and two homotetramers comprise the asymmetric crystallographic unit. each subunit contains two t-fold domains of betabetaalp ...200818645230
evidence for specificity of cultivable bacteria associated with arbuscular mycorrhizal fungal spores.bacteria associated with arbuscular mycorrhizal (am) fungal spores may play functional roles in interactions between am fungi, plant hosts and defence against plant pathogens. to study am fungal spore-associated bacteria (amb) with regard to diversity, source effects (am fungal species, plant host) and antagonistic properties, we isolated amb from surface-decontaminated spores of glomus intraradices and glomus mosseae extracted from field rhizospheres of festuca ovina and leucanthemum vulgare. a ...200818631178
further insight into the mechanism of stereoselective proton abstraction by bacterial copper amine oxidase.during the catalytic reaction of copper amine oxidase, one of the two prochiral hydrogen atoms at the c1 position of substrate amine is stereoselectively abstracted by a conserved asp residue serving as a general base. using stereospecifically deuterium-labeled enantiomers of 2-phenylethylamine, we previously showed that the pro-s alpha-proton is abstracted by the enzyme from arthrobacter globiformis (agao) [uchida, m., et al. (2003) biosci. biotechnol. biochem. 67, 2664-2667]. more recently, we ...200818627131
toxicity of homologous series of organic solvents for the gram-positive bacteria arthrobacter and nocardia sp. and the gram-negative bacteria acinetobacter and pseudomonas sp.the toxicity of homologous series of organic solvents has been investigated for the gram-positive bacteria, arthrobacter sp. and nocardia sp., and the gram-negative bacteria, acinetobacter sp. and pseudomonas sp. the hydrophobicity of the solvent, expressed by its logp(octanol), proves to be a good measure for the toxicity of solvents in a two-phase system. the transition from toxic to nontoxic solvents occurs between logp(octanol) 3 and 5 and depends on the homologous series. no correlation has ...199318613108
complexes of the copper-containing amine oxidase from arthrobacter globiformis with the inhibitors benzylhydrazine and tranylcypromine.complexes of arthrobacter globiformis amine oxidase (agao) with the inhibitors benzylhydrazine and tranylcypromine (an antidepressant drug) have been refined at 1.86 and 1.65 a resolution, respectively. both inhibitors form covalent adducts with the tpq cofactor. a tyrosine residue, proposed to act as a gate to the agao active site, is in its open conformation.200818607080
phylogenetic analysis on the bacteria producing non-volatile fungistatic substances.this study characterized the soil bacteria producing non-volatile fungistatic substances. among the 2,100 colonies of soil bacteria randomly isolated from seven agricultural soil samples, 518 isolates (24.67% of total) showed fungistatic activity toward nematophagous fungi paecilomyces lilacinus and trichoderma viride by producing non-volatile substances. a phylogenetic analysis based on amplified ribosomal dna restriction analysis (ardra) and 16s rdna sequence placed the 518 bacteria in three g ...200818604493
purification and characterization of cyclic maltosyl-(1-->6)-maltose hydrolase and alpha-glucosidase from an arthrobacter globiformis strain.cyclic maltosyl-maltose [cmm, cyclo-[-->6)-alpha-d-glcp-(1-->4)-alpha-d-glcp-(1-->6)-alpha-d-glcp-(1-->4)-alpha-d-glcp-(1-->]], a novel cyclic tetrasaccharide, has a unique structure. its four glucose residues are joined by alternate alpha-1,4 and alpha-1,6 linkages. cmm is synthesized from starch by the action of 6-alpha-maltosyltransferase from arthrobacter globiformis m6. recently, we determined the mechanism of extracellular synthesis of cmm, but the degrading pathway of the saccharide remai ...200818603794
activity and stability of an entrapped-cell system for the delta(1)-dehydrogenation of steroids in organic media.whole arthrobacter simplex cells entrapped in kappa-carra-geenan or in two types of polyurethane foam, or adsorbed on silanized celite, were tested for the delta(1)-dehydrogenation of hydrocortisone and its derivatives in organic media. catalytic activity and stability levels were evaluated for the immobilized cells in buffer with 2.5% (vol/vol) methanol, and in three buffer-saturated solvents (n-octan-1-ol, n-decan-1-ol, and chloroform). the addition of glutamate to the immobilization support s ...199218601223
effect of adsorbents on degradation of toxic organic compounds by coimmobilized systems.the use of coimmobilized systems for treatment of toxic organic compounds has been proposed. the proposed approach combines the use of adsorbents and laboratory identified microorganisms immobilized in a protective permeable barrier to achieve a greater degree of control over the remediation process. this study was launched to understand the effect of adsorbents and changes in adsorption on the degradation of toxic compounds by coimmobilized systems. the specific case studied involved the degrad ...199218600991
steroid bioconversion in a microemulsion system.the delta(1,2)-dehydrogenation of high concentrations of the steroid -methyl-reichstein's compound s-21-acetate (16mrsa) in a microemulsion system was studied using heat-dried and thawed arthrobacter simplex cells as biocatalyst. the microemulsion system consists of an organic phase [75-95% (v/v)] with steroid (1-60 g/l(tot)), an aqueous phase [5-25% (v/v)] containing the cells (5-30 g/l(tot)), and a neutral surfactant (5-20 g/l organic solvent). benzene derivatives, which solubilize 16mrsa up t ...199118600717
effects of solvent molecular toxicity and microenvironment composition on the delta(1) dehydrogenataon activity of arthrobacter simplex cells.solvent selection tests were carried out for the delta(1) dehydrogenation of 6-alpha-methylhydrocortisone-21-acetate by arthrobacter simplex cells in the presence of organic solvents. solubility limits were determined for substrate and product in dry and water-saturated solvents and solvent mixtures. molecular toxicity levels were estimated by measuring the dehydrogenation activity decay of freely suspended cells incubated in solvent-saturated aqueous media. chloroform and n-decan-1-ol were the ...199118597345
ultrasound-enhanced bioprocess. ii: dehydrogenation of hydrocortisone by arthrobacter simplex.dehydrogenation of hydrocortisone by agitated suspensions of free and immobilized cells of arthrobacter simplex atcc 6946 was investigated under controlled ultrasonic irradiation at a frequency of 20 kh(z). the microbial conversion was optimized first with respect to mechanical agitation and subsequently with respect to an additionally superimposed sonication. the optimization of ultrasound intensity and its mode of application were established at a level which maintained the structural integrit ...199118597329
characterization and validation of a bioluminescent bioreporter for the direct detection of escherichia coli.a two-component bacteriophage-based bioluminescent reporter system was developed for the detection of escherichia coli in environmental samples. the bioreporter system consists of a luxi integrated lambda bacteriophage and a lux-based bioluminescent reporter cell that responds to the infection event through acyl-homoserine lactone (ahl) mediated quorum sensing and bioluminescent signal stimulation. this work addresses the ability of the bioreporter system to detect and quantify the target pathog ...200818593593
immobilization of arthrobacter simplex in a thermally reversible hydrogel: effect of temperature cycling on steroid conversion.arthrobacter simplex cells, which convert the steroid hydrocortisone to prednisolone, have been entrapped in a thermally reversible hydrogel. such hydrogels exhibit a lower critical solution temperature (lcst) wherein the gel shrinks and deswells when it is warmed through its lcst, and then reversibly expands and reswells when it is cooled below the lcst. the immobilized cell-hydrogel system has been thermally cycled between two temperatures, each below the lcst. the upper temperature was select ...199018592505
multi-compound electrophoretic assays for tyramine oxidase with a uv area detector imaging multiple windows on a looped capillary.active pixel sensor uv area imaging and capacitively coupled contactless conductivity detection have been applied in an electrophoretically mediated microanalysis (emma) assay for substrate specificity of tyramine oxidase (arthrobacter sp.). use of the uv area imaging detector to monitor four windows in a capillary with three loops provided intrinsic self-referencing for all species and identified tyramine and 2-phenethylamine as the only reactive components in a multi-compound mixture. continuo ...200818589431
kinetic model for the regulation of redox reaction in steroid transformation by arthrobacter globiformis cells.a kinetic model of hydrocortisone transformation was developed in studies of the kinetics of biochemical systems. the regulatory bases of the model are the biosynthesis of steroid-transforming enzymes and their activity, the level of endogenous substrates, the respiratory chain activity, and the initial concentrations of reagents. when compared, the experimental data completely coincide with the results of the computer modeling, the coincidence being not only qualitative but also quantitative. i ...198918587967
kinetic model of hydrocortisone 1-en-dehydrogenation by arthrobacter globiformis.a kinetic model of the hydrocortisone-to-prednisolone transformation by arthrobacter globiformis is constructed using the experimental data obtained in studies of this process. besides adequately describing experimental data, the model allows one to determine the relation between hydrocortisone oxidation and the level of endogenous substrates in bacterial cells, and the relation between the saturating concentration of hydrocortisone in the enzymic system of bacteria and the content of endogenous ...198918587966
activated sludge treatment of synthetic wastewater containing pentachlorophenol.activated sludge treatment of a pentachlorophenol (pcp)-containing synthetic waste was examined. with a waste containing some sugars, and 40-120 mg/l pcp, laboratory activated sludge required about seven days for acclimation. however, the prior addition of a quasipure culture of pcp-metabolizing arthrobacter resulted in immediate acclimation. even with acclimated sludge, however, the system was upset for two days by a simple step change from 40 to 120 mg/l of pcp. the stability of the system to ...198318574814
treatment of chromium(vi) solutions in a pilot-scale bioreactor through a biofilm of arthrobacter viscosus supported on gac.the aim of this work is to evaluate the applicability of a biofilm to the removal of chromium in solution, at a pilot scale. the effect of the initial concentration of metal on the biosorption behavior of an arthrobacter viscosus biofilm supported on granular activated carbon, in batch and column essays was also analyzed. six isotherm equations have been tested in the present study. the best fit was obtained with the freundlich model. it was observed that as the initial chromium concentration in ...200918565747
plasmon microscopy and imaging ellipsometry of artrobacter oxydans attached on polymer films.the attachment of artrobacter oxydans 1,388 on a newly synthesized biodegradable copolymer of poly-(hexanlactam)-co-block-poly-(delta-valerolactone) is investigated by optical, microscopic and biochemical methods. the potentials of surface plasmon microscopy and imaging ellipsometry for detecting microorganisms when al films are used to excite plasmons is assessed by comparing images obtained by these methods with dark field microscopy pictures. the experimental results demonstrate that in this ...200818565743
coimmobilization of substrate and biocatalyst: a method for bioconversion of poorly soluble substances in water milieu.coimmobilization of biocatalyst and substrate was studied as a method to increase the conversion rate in systems with substrates of extremely low solubility in water. the system studied was the conversion of hydrocortisone to prednisolone by arthrobacter simplex. as a matrix for coimmobilization, alginate turned out to be superior to agar and agarose. after the reaction was complete, the beads were solubilized, andthe cells recovered for reuse, by centrifugation, whereas the prednisolone was ext ...198618561232
pilot-plant production of prednisolone using calcium alginate immobilized arthrobacter simplex.the maximum conversion of hydrocortisone suspensions at initial substrate concentrations greater than 4 g/l by immobilized arthrobacter simplex in a batch reactor was 80-85%. by feeding hydrocortisone suspensions continuously to either a fed-batch-operated stirred tank reactor or to a continuous-flow airlift loop reactor, at a rate such that the soluble hydrocortisone concentration in the reactor remained ca. 0.05 g/l, 95% conversion of substratewas obtained at final product concentrations excee ...198618561228
mathematical simulation of pseudo-crystallofermentation of hydrocortisone by arthrobacter simplex.a mathematical model has been developed to simulate the pseudo-crystallofermentation process of hydrocortisone by arthrobacter simplex. the model describing the process included considerations on the kinetics of microbial growth, the rate of enzyme formation, the rate of substrate dissolution, the rate of solute crystallization, and the kinetics of enzymatic reaction. the system of equations was solved numerically by the runge-kutta-gill method. the good agreement between prediction and experime ...198518553666
growth and phosphate uptake of a high phosphate accumulating bacterium, arthrobacter globiformis pab-6 in continuous culture.a high phosphate accumulating bacterium, arthrobacter globiformis pab-6, was grown in a chemostat under glucose-limitation. two different growth patterns at steady state with various dilution rates were obtained. in one case, cells having a coccus shape tended to washout at a low dilution rate, 0.2 (h(-1)). in another, cells with a rod shape grew faster and gave a good steady-state growth at a dilution rate of 0.4. such a close relationship between growth rate and cell morphology was found both ...198318551481
thermodynamic analysis of denaturant-induced unfolding of hodc69s protein supports a three-state mechanism.thermodynamic stability parameters and the equilibrium unfolding mechanism of his 6hodc69s, a mutant of 1 h-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (hod) having a cys to ser exchange at position 69 and an n-terminal hexahistidine tag (his 6hodc69s), have been derived from isothermal unfolding studies using guanidine hydrochloride (gdnhcl) or urea as denaturants. the conformational changes were monitored by following changes in circular dichroism (cd), fluorescence, and dynamic light scattering ...200818549245
mode of uptake of insoluble solid substrates by microorganisms. i: sterol uptake by an arthrobacter species.the mode of uptake of sterols, which are nearly insoluble in water by an arthrobacter species, was studied on the basis of substrate transfer via the aqueous phase (solubilization/pseudosolubilization) and through direct contact with sterol particles. growth of the organism, on stero powder was predominantly in nonlogarithmic in character, indicating a possible limitation of substrate transfer. soluble sterol was shown to be the preferential form of the substrate for assimilation by the organism ...198318548628
production of surfactant by arthrobacter paraffineus atcc 19558.a. paraffineus atcc 19558 grown in mmsm (modified mineral salts medium) containing hydrocarbon produced surfactant, with a maximum cmc(-1) value obtained by using hexadecane as the carbon source. no activity of surface active agent in whole broth was observed when glucose was used in the mmsm instead of hexadecane. the biomass concentration obtained with glucose was about 40% of that obtained with hexadecane. glucose (4%) in the medium containing hexadecane caused a 27 and 21% decrease of biomas ...198218546108
isolation of alkali-tolerant benzene-degrading bacteria from a contaminated aquifer.to isolate benzene-degrading strains from neutral and alkaline groundwaters contaminated by benzene, toluene, ethylbenzene, xylenes (btex) from the siren aquifer, uk, and to test their effective ph range and ability to degrade tex.200818544140
high benzene concentrations can favour gram-positive bacteria in groundwaters from a contaminated aquifer.exposure to pollution exerts strong selective pressure on microbial communities, which may affect their potential to adapt to current or future environmental challenges. in this microcosm study, we used dna fingerprinting based on 16s rrna genes to document the impact of high concentrations of benzene on two bacterial communities from a benzene-contaminated aquifer situated below a petrochemical plant (siren, uk). the two groundwaters harboured distinct aerobic benzene-degrading communities able ...200818540887
on the role of histidine 351 in the reaction of alcohol oxidation catalyzed by choline oxidase.choline oxidase catalyzes the four-electron, flavin-linked oxidation of choline to glycine betaine with transient formation of an enzyme-bound aldehyde intermediate. the recent determination of the crystal structure of choline oxidase to a resolution of 1.86 a established the presence of two histidine residues in the active site, which may participate in catalysis. his466 was the subject of a previous study [ghanem, m., and gadda, g. (2005) biochemistry 44, 893-904]. in this study, his351 was re ...200818540638
endohexosaminidase-catalysed glycosylation with oxazoline donors: fine tuning of catalytic efficiency and reversibility.a complete series of oxazoline di-, tri-, tetra-, and hexasaccharides, corresponding to the core sections of n-linked glycoprotein high mannose glycans, together with the corresponding oligosaccharides containing a central glucose unit, were synthesised and tested as glycosyl donors for glycosylation of a glcnacasn glycosyl amino acid catalysed by the endohexosaminidases m (endo m), a (endo a) and h (endo h). whilst endo h did not catalyse any glycosylation reactions, both endo m and endo a effi ...200818537207
selection and identification of bacterial strains with methyl-tert-butyl ether, ethyl-tert-butyl ether, and tert-amyl methyl ether degrading capacities.nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/l of one of the following gasoline oxygenates: methyl-tert-butyl ether (mtbe), ethyl-tert-butyl ether (etbe), and tert-amyl methyl ether (tame). these strains were identified by amplification of their 16s rrna gene, using fdl and rd1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and ...200818522454
manipulation of sinapine, choline and betaine accumulation in arabidopsis seed: towards improving the nutritional value of the meal and enhancing the seedling performance under environmental stresses in oilseed crops.sinapoylcholine (sinapine) is the most abundant antinutritional phenolic compound in cruciferous seeds. the quaternary ammonium compounds, choline, betaine and n,n-dimethylglycine, reside along a biosynthetic pathway linked to the synthesis of membrane phospholipids and neurotransmitters with various biological functions. in chicken, choline intake is required for optimal egg-laying performance and a choline supplement in diet is positively correlated with weight gains. a key step in sinapine bi ...200818515127
analysis of enzyme-treated red blood cell surface and haemagglutination using a theory of soft-particle electrophoresis.enzymatic treatment of red blood cells is thought to reduce the cell zeta (zeta) potential, effectively decreasing the distance between cells to less than the length of an immunoglobulin g antibody binding site, and resulting in agglutination of cells. however, the zeta potential given by smoluchowski's formula is based on theories of the electrophoresis of hard colloidal particles. a theory has recently been developed for the electrophoresis of colloidal particles covered with polyelectrolytes, ...200818510578
the shortest wire. 200818508968
enantiomer-specific binding of ruthenium(ii) molecular wires by the amine oxidase of arthrobacter globiformis.the copper amine oxidase from arthrobacter globiformis (agao) is reversibly inhibited by molecular wires comprising a ru(ii) complex head group and an aromatic tail group joined by an alkane linker. the crystal structures of a series of ru(ii)-wire-agao complexes differing with respect to the length of the alkane linker have been determined. all wires lie in the agao active-site channel, with their aromatic tail group in contact with the trihydroxyphenylalanine quinone (tpq) cofactor of the enzy ...200818507382
swapping metals in fe- and mn-dependent dioxygenases: evidence for oxygen activation without a change in metal redox state.biological o(2) activation often occurs after binding to a reduced metal [e.g., m(ii)] in an enzyme active site. subsequent m(ii)-to-o(2) electron transfer results in a reactive m(iii)-superoxo species. for the extradiol aromatic ring-cleaving dioxygenases, we have proposed a different model where an electron is transferred from substrate to o(2) via the m(ii) center to which they are both bound, thereby obviating the need for an integral change in metal redox state. this model is tested by usin ...200818492808
[restriction endonuclease asi256i recognizing the nucleotide sequence 5'-gatc-3'].a strain producing a restriction endonuclease was isolated from soil samples and identified as the arthrobacter sp. strain ck256. the enzyme produced by this strain was termed asi2561. the isolation procedure for this enzyme was described, and the optimal conditions for its function were determined. it was shown that the restriction endonuclease asi256i is a true isoschizomer of mboi, it has a temperature optimum of 6 degrees c, and can be used in molecular-biological and genetic-engineering stu ...200818491594
study of cadmium, zinc and lead biosorption by orange wastes using the subsequent addition method.the biosorption of several metals (cd2+, zn2+ and pb2+) by orange wastes has been investigated in binary systems. multicomponent sorption isotherms were obtained using an original procedure, similar to that proposed by pagnanelli et al. [pagnanelli, f., petrangeli, m.p., toro, l., trifoni, m., veglio, f., 2001a. biosorption of metal ions on arthrobacter sp.: biomass characterization and biosorption modelling. environ. sci. technol. 34, 2773-2778] for monoelement systems, known as subsequent addi ...200818440805
structure of 2,6-dihydroxypyridine 3-hydroxylase from a nicotine-degrading pathway.the enzyme 2,6-dihydroxypyridine-3-hydroxylase catalyzes the sixth step of the nicotine degradation pathway in arthrobacter nicotinovorans. the enzyme was produced in escherichia coli, purified and crystallized. the crystal structure was solved at 2.6 a resolution, revealing a significant structural relationship with the family of fad-dependent aromatic hydroxylases, but essentially no sequence homology. the structure was aligned with those of the established family members, showing that the fad ...200818440023
genetic analysis of phenylacetic acid catabolism in arthrobacter oxydans cect386.arthrobacter oxydans cect386 is a gram-positive bacterium able to use either phenylacetic acid or phenylacetaldehyde as the sole carbon and energy source for aerobic growth. genes responsible for the catabolism of these compounds have been located at two chromosomal regions and were organized in one isolated paan gene and two putative paa operons, one consisting of the paad, paaf, tetr and prot genes, and one consisting of the paag, paah, paai, paaj, paak and paab genes. the identity of the paaf ...200818437357
[isolation of antibiotic resistance bacterial strains from east siberia permafrost sediments].a collection of bacterial antibiotic resistance strains isolated from arctic permafrost subsoil sediments of various age and genesis was created. the collection included approximately 100 strains of gram-positive (firmicutes, arthrobacter) and gram-negative bacteria (bacteroidetes, gamma-proteobacteria, and alpha-proteobacteria) resistant to aminoglycoside antibiotics (gentamycin, kanamycin, and streptomycin), chloramphenicol and tetracycline. antibiotic resistance spectra were shown to differ i ...200818409385
catalytic mechanism of inulinase from arthrobacter sp. s37.detailed catalytic roles of the conserved glu323, asp460, and glu519 of arthrobacter sp. s37 inulinase (enia), a member of the glycoside hydrolase family 32, were investigated by site-directed mutagenesis and ph-dependence studies of the enzyme efficiency and homology modeling were carried out for enia and for d460e mutant. the enzyme efficiency (k(cat)/k(m)) of the e323a and e519a mutants was significantly lower than that of the wild-type due to a substantial decrease in k(cat), but not due to ...200818395004
chemostat selection of a bacterial community able to degrade s-triazinic compounds: continuous simazine biodegradation in a multi-stage packed bed biofilm reactor.using a successive transfer method on mineral salt medium containing simazine, a microbial community enriched with microorganisms able to grow on simazine was obtained. afterwards, using a continuous enrichment culture procedure, a bacterial community able to degrade simazine from an herbicide formulation was isolated from a chemostat. the continuous selector, fed with a mineral salt medium containing simazine and adjuvants present in the commercial herbicide formulation, was maintained in opera ...200818392868
functional diversity and electron donor dependence of microbial populations capable of u(vi) reduction in radionuclide-contaminated subsurface sediments.in order to elucidate the potential mechanisms of u(vi) reduction for the optimization of bioremediation strategies, the structure-function relationships of microbial communities were investigated in microcosms of subsurface materials cocontaminated with radionuclides and nitrate. a polyphasic approach was used to assess the functional diversity of microbial populations likely to catalyze electron flow under conditions proposed for in situ uranium bioremediation. the addition of ethanol and gluc ...200818378664
arthrobacter soli sp. nov., a novel bacterium isolated from wastewater reservoir sediment.a novel gram-positive bacterium, designated syb2t, was isolated from wastewater reservoir sediment, and a polyphasic taxonomic study was conducted based on its morphological, physiological, and biochemical features, as well as the analysis of its 16s rrna gene sequence. during the phylogenetic analysis of the strain syb2t, results of a 16s rrna gene sequence analysis placed this bacterium in the genus arthrobacter within the family micrococcaceae. syb2t and arthrobacter protophormiae atcc 19271t ...200818337691
characterization of a cryptic plasmid from a greenland ice core arthrobacter isolate and construction of a shuttle vector that replicates in psychrophilic high g+c gram-positive recipients.over 60 greenland glacial isolates were screened for plasmids and antibiotic resistance/sensitivity as the first step in establishing a genetic system. sequence analysis of a small, cryptic, 1,950 bp plasmid, p54, from isolate gic54, related to arthrobacter agilis, showed a region similar to that found in theta replicating rhodococcus plasmids. a 6,002 bp shuttle vector, psvj21, was constructed by ligating p54 and puc18 and inserting a chloramphenicol acetyl transferase (cat) cassette conferring ...200818335166
biofiltration of trimethylamine, dimethylamine, and methylamine by immobilized paracoccus sp. cp2 and arthrobacter sp. cp1.a biofilter using granular activated carbon with immobilized paracoccus sp. cp2 was applied to the elimination of 10-250 ppm of trimethylamine (tma), dimethylamine (dma), and methylamine (ma). the results indicated that the system effectively treated ma (>93%), dma (>90%), and tma (>85%) under high loading conditions, and the maximum degradation rates were 1.4, 1.2, and 0.9g-nkg(-1) gac d(-1). among the three different amines treated, tma was the most difficult to degrade and resulted in ammonia ...200818331754
application of pcr-sscp for molecular epidemiological studies on the exposure of farm children to bacteria in environmental dust.the environmental exposure of farm children to microorganisms in dust has become a focus of interest, since microbial exposure on farms has been related to a reduced prevalence of asthma and atopic diseases in children. previous studies almost exclusively focused on the determination of microbial counts using conventional culturing or the determination of microbial compounds i.e. endotoxins. in this study pcr-sscp (single-strand conformation polymorphism) was modified for characterising bacteria ...200818321601
synthesis and inhibitory activity of oligosaccharide thiazolines as a class of mechanism-based inhibitors for endo-beta-n-acetylglucosaminidases.a facile synthesis of oligosaccharide-thiazoline derivatives of n-glycans as a novel class of inhibitors for endo-beta-n-acetylglucosaminidases was described. it was found that the external sugar residues on the n-glycan core could enhance the inhibitory potency. while the manbeta1,4glcnac- and man3glcnac-thiazolines were only moderate inhibitors, the large man9glcnac-thiazoline demonstrated potent inhibitory activity, with an ic(50) of 0.22 and 0.42 microm against the arthrobacter enzyme (endo- ...200818304822
rapid mineralization of the phenylurea herbicide diuron by variovorax sp. strain srs16 in pure culture and within a two-member consortium.the phenylurea herbicide diuron [n-(3,4-dichlorophenyl)-n,n-dimethylurea] is widely used in a broad range of herbicide formulations, and consequently, it is frequently detected as a major water contaminant in areas where there is extensive use. we constructed a linuron [n-(3,4-dichlorophenyl)-n-methoxy-n-methylurea]- and diuron-mineralizing two-member consortium by combining the cooperative degradation capacities of the diuron-degrading organism arthrobacter globiformis strain d47 and the linuro ...200818296530
[isolation and degrading characters of chlorpyrifos degrading bacteria xz-3].a strain of bacterium xz-3 capable of highly degrading chlorpyrifos was screened from the soil sample collected from a pesticide plant after taming and enrichment. based on analysis of phenotype, physiological and biochemical characters and 16s rdna, xz-3 was identified as arthrobacter sp.. the effects of carbon source, ph, temperature and chlorpyrifos concentration on degradation were determined. the growth of bacteria in culture media were measured by visible absorption spectrophotometry under ...200718290445
commercial ripening starter microorganisms inoculated into cheese milk do not successfully establish themselves in the resident microbial ripening consortia of a south german red smear cheese.production of smear-ripened cheese critically depends on the surface growth of multispecies microbial consortia comprising bacteria and yeasts. these microorganisms often originate from the cheese-making facility and, over many years, have developed into rather stable, dairy-specific associations. while commercial smear starters are frequently used, it is unclear to what degree these are able to establish successfully within the resident microbial consortia. thus, the fate of the smear starters ...200818281427
novel chromium tolerant microorganisms: isolation, characterization and their biosorption capacity.effluent from tannery, electroplating and electronic industries contain chromium which is highly toxic. this paper reports isolation of chromium tolerant microorganisms from solid waste as well as liquid effluent of an electroplating industry. nine isolates were obtained that can tolerate chromium concentration up to 700mg/l. they reach their stationary phase within 8-12h and can biosorb 95% of initial 200mg/l concentration of chromium within 4-10h. fourier transform infra red analysis of the bi ...200818272220
the effect of cysteine on production of volatile sulphur compounds by cheese-ripening bacteria.the effect of cysteine on the ability of smear cheese-ripening bacteria (brevibacterium linens and arthrobacter spp) to produce volatile sulphur compounds (vsc) from methionine was studied. these bacteria were cultivated in a synthetic medium supplemented with various cysteine concentrations with or without methionine. cultures with only cysteine showed slightly lower levels of vsc produced and an unpleasant odour like rotten eggs, resulting from hydrogen sulphide production. the levels and prof ...200818262300
comparative analysis of eight arthrobacter plasmids.despite the prevalence of arthrobacter in the environment little is known about their plasmids, or the capacity of arthrobacter plasmids to mediate horizontal gene transfer. in this study, we compared eight plasmids from five arthrobacter strains in order to identify putative core maintenance genes for replication, segregation, and conjugation. iteron like sequences were identified on some of the plasmids; however, no genes with obvious similarity to known replication sequences such as an origin ...200818241920
degradation of 4-fluorophenol by arthrobacter sp. strain if1.a gram-positive bacterial strain capable of aerobic biodegradation of 4-fluorophenol (4-fp) as the sole source of carbon and energy was isolated by selective enrichment from soil samples collected near an industrial site. the organism, designated strain if1, was identified as a member of the genus arthrobacter on the basis of 16s ribosomal rna gene sequence analysis. arthrobacter strain if1 was able to mineralize 4-fp up to concentrations of 5 mm in batch culture. stoichiometric release of fluor ...200818228015
arthrobacter oryzae sp. nov. and arthrobacter humicola sp. nov.two novel bacterial strains were isolated from a paddy soil sample collected in japan using gpm agar plates supplemented with superoxide dismutase and/or catalase. the strains were gram-positive, catalase-positive and motile, with lysine as the peptidoglycan diagnostic diamino acid and acetyl as the peptidoglycan acyl type. the major menaquinone was mk-9(h(2)). mycolic acids were not detected. the g+c content of the dna was 66-68 mol%. on the basis of phenotypic analysis, 16s rrna gene sequence ...200818175682
[effect of quinocitrinines from the fungus penicillium citrinum on the respiration of yeasts and bacteria].we studied the effect of quinocitrinines on the respiratory activity of yeasts (yarrowia lipolytica) and bacteria (arthrobacter globiformis). quinocitrinines were shown to activate respiration of native cells in both types of organisms. studies of yeast mitochondria showed that quinocitrinine exerts an uncoupling effect on oxidative phosphorylation, which activates the respiration, reduces the respiratory control, and decreases the adp/o ratio. experiments with intact mitochondria and native cel ...200718173114
[a case of catheter-related bacteremia by arthrobacter woluwensis.].arthrobacter woluwensis, a catalase-positive coryneform bacterium recognized as an opportunistic pathogen, was repeatedly isolated from the blood of a 56-year-old male patient with metastatic colon cancer. the isolate was identified by various phenotypic tests and by sequencing analysis of 16s rrna. antimicrobial susceptibility testing was performed by e-test; the mics to vancomcyin, cefotamine, and penicillin were 1.5 microg/ml, >64 microg/ml, and 4 microg/ml, respectively. the patient was trea ...200618156709
arthrobacter subterraneus sp. nov., isolated from deep subsurface water of the south coast of korea.strain ch7t, a pale yellow-pigmented bacterium and new isolate from deep subsurface water of the south coast of korea, was subjected to a polyphasic taxonomic study. ch7t grew between 5 and 37 degrees c, ph 5.3-10.5, and tolerated up to 13% nacl. a phylogenetic analysis based on 16s rrna gene sequences showed that strain ch7t was associated with the genus arthrobacter and phylogenetically closely related to the type strains arthrobacter tumbae (99.4%) and arthrobacter parietis (99.1%). however, ...200718092474
facultative but persistent trans-generational immunity via the mother's eggs in bumblebees.it is widely acknowledged that a mother, and the maternal environment, can have a profound effect on the phenotype of her offspring. for example, immunocompetent vertebrate mothers can pass on immune factors to their otherwise immune naïve offspring. recently, it has also been demonstrated in invertebrates that maternal contact with pathogens and immune elicitors can have a positive impact on offspring resistance and immune system components. here, using a cross-fostering design, we show that tr ...200718088585
effect of shadowing on survival of bacteria under conditions simulating the martian atmosphere and uv radiation.spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in atacama desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated martian atmospheric and uv irradiation conditions. all non-spore-forming cells that were prepared in nutrient-depleted, 0.2-microm-filtered desert soil (dse) microcosms and desiccated for 75 days on aluminum died, whereas cells p ...200818083857
effect of immobilization on kinetic and thermodynamic characteristics of sulfide oxidase from arthrobacter species.in order to determine the impact of immobilization on biocatalytic efficacy of sulfide oxidase, the kinetic and thermodynamic properties of native and deae-cellulose immobilized sulfide oxidase from arthrobacter species fr-3 were evaluated. immobilization increased the catalytic efficiency of sulfide oxidase by producing a lower michaelis-menten constant (km) and a higher rate of catalysis (vmax) at different temperatures. the first-order kinetic analysis of thermal denaturation demonstrated tha ...200818080911
two closely related pathways of nicotine catabolism in arthrobacter nicotinovorans and nocardioides sp. strain js614.a virtually identical nicotine catabolic pathway including the heterotrimeric molybdenum enzyme nicotine and 6-hydroxy-pseudo-oxynicotine dehydrogenase, 6-hydroxy-l: -nicotine oxidase, 2,6-dihydroxy-pseudo-oxynicotine hydrolase, and 2,6-dihydroxypyridine hydroxylase have been identified in a. nicotinovorans and nocardioides sp. js614. enzymes catalyzing the same reactions and similar protein antigens were detected in the extracts of the two microorganisms. nicotine blue and methylamine, two end ...200818071673
chromate reduction by arthrobacter cr47 in biofilm packed bed reactors.bacterial strain cr47 was isolated from a landfarming process soil sample. it was identified, by 16s rdna sequencing, as arthrobacter sp. the time course of the cr(vi) reduction was monitored in batch operated packed bed biofilm reactors (12 ml void volume) and in recirculating packed bed biofilm reactors (100 ml void volume) inoculated with bacterial strain cr47. the reduction was evaluated with, 30 mg l(-1) cr(vi) laboratory solutions prepared with k2cr2o7 and enriched with glucose-minimal med ...200818063473
[screening and function analysis of a cyclohexanone-degrading bacterium cn1 from deep sea sediment].micrococcu luteus cn1 was found to be able to utilize cyclohexanone well from the strains originally isolated from pacific ocean sediment. the optimum conditions for its growth were determined as 25 degrees c -37 degrees c, ph 8, salinity 6%. it could survive in the medium with high concentration of cyclohexanone ( > 44% v/v), and grew most vigorously in medium with 16.7% (v/v) cyclohexanone. cn1 could transform cyclohexanol to cyclohexanone which could be further degraded and mineralized quickl ...200718062257
[study on the atrazine-degrading genes in arthrobacter sp. ag1].atrazine could be used as the sole carbon, nitrogen and energy sources for growth by strain arthrobacter sp. ag1, and the atrazine-degrading genes of ag1 were found to be the combination of trzn, atzb and atzc. the atrazine chloride hydrolysase gene trzn was cloned by pcr amplification,whose sequence shared 99% identity with that of norcardioides sp. c190. two large plasmids were found in ag1,and trzn and atzb were confirmed to be localized on the larger plasmid pag1 by the method of southern hy ...200718051853
two bacterial entophytes eliciting both plant growth promotion and plant defense on pepper (capsicum annuum l.).plant growth-promoting rhizobacteria (pgpr) have the potential to be used as microbial inoculants to reduce disease incidence and severity and to increase crop yield. some of the pgpr have been reported to be able to enter plant tissues and establish endophytic populations. here, we demonstrated an approach to screen bacterial endophytes that have the capacity to promote the growth of pepper seedlings and protect pepper plants against a bacterial pathogen. initially, out of 150 bacterial isolate ...200718051359
cloning, expression, and characterization of bacillus sp. snu-7 inulin fructotransferase.a gene encoding inulin fructotransferase (di-d-fructofuranose 1,2': 2,3' dianhydride [dfa iii]-producing iftase, ec 4.2.2.18) from bacillus sp. snu-7 was cloned. this gene was composed of a single, 1,353-bp open reading frame encoding a protein composed of a 40-amino acid signal peptide and a 410-amino acid mature protein. the deduced amino acid sequence was 98% identical to arthrobacter globiformis c11-1 iftase (dfa iii-producing). the enzyme was successfully expressed in e. coli as a functiona ...200718051351
microbial community profiling in cis- and trans-dichloroethene enrichment systems using denaturing gradient gel electrophoresis.the effective and accurate assessment of the total microbial community diversity is one of the primary challenges in modem microbial ecology, especially for the detection and characterization of unculturable populations and populations with a low abundance. accordingly, this study was undertaken to investigate the diversity of the microbial community during the biodegradation of cis- and trans-dichloroethenes in soil and wastewater enrichment cultures. community profiling using pcr targeting the ...200718051265
biphenyl-utilizing bacteria and their functional genes in a pine root zone contaminated with polychlorinated biphenyls (pcbs).bacteria and functional genes associated with biphenyl (bp) degradation in the root zone of an austrian pine (pinus nigra l.) growing naturally in polychlorinated-bp (pcb)-contaminated soil were identified using stable isotope probing (sip) integrated with comprehensive functional gene analyses. sip revealed 75 different genera that derived carbon from 13c-bp, with pseudonocardia, kribella, nocardiodes and sphingomonas predominating carbon acquisition. rhodococcus spp. were not detected with sip ...200718043623
simultaneous mineralization of glyphosate and diuron by a consortium of three bacteria as free- and/or immobilized-cells formulations.a bacterial consortium able to mineralize two herbicides, glyphosate (pseudomonas 4asw) and diuron (arthrobacter sp. n4 and delftia acidovorans), was cultivated in both a synthetic culture medium without phosphate and a sediment extract medium. in the aim at optimizing glyphosate and diuron mineralization, all the combinations, i.e., free and/or immobilized cells in ca-alginate beads were tested. with the synthetic medium, the simultaneous mineralization of glyphosate and diuron required at leas ...200818026726
bacterial endophytes contribute to abiotic stress adaptation in pepper plants (capsicum annuum l.).endophytes are nonpathogenic plant-associated bacteria that can play an important role in plant vitality and may confer resistance to abiotic or biotic stress. the effects of 5 endophytic bacterial strains isolated from pepper plants showing 1-aminocyclopropane-1-carboxylate deaminase activity were studied in sweet pepper under in vitro conditions. four of the strains tested showed production of indole acetic acid. plant growth, osmotic potential, free proline content, and gene expression were m ...200718026213
aerobic uranium (vi) bioprecipitation by metal-resistant bacteria isolated from radionuclide- and metal-contaminated subsurface soils.in this study, the immobilization of toxic uranium [u(vi)] mediated by the intrinsic phosphatase activities of naturally occurring bacteria isolated from contaminated subsurface soils was examined. the phosphatase phenotypes of strains belonging to the genera, arthrobacter, bacillus and rahnella, previously isolated from subsurface soils at the us department of energy's (doe) oak ridge field research center (orfrc), were determined. the orfrc represents a unique, extreme environment consisting o ...200717991039
isolation and assessment of phytate-hydrolysing bacteria from the delmarva peninsula.the delaware-maryland-virginia (delmarva) peninsula, flanking one side of the chesapeake bay, is home to a substantial broiler chicken industry. as such, it produces a significant amount of manure that is typically composted and spread onto local croplands as a fertilizer. phytate (myo inositol hexakisphosphate), the major form of organic phosphorus in the manure, can be hydrolysed by microorganisms to produce orthophosphate. orthophosphate is a eutrophication agent which can lead to algal bloom ...200717991037
short-term effects of amoxicillin on bacterial communities in manured soil.antibiotic-resistant bacteria, nutrients and antibiotics that enter the soil by means of manure may enhance the proportion of bacteria displaying antibiotic resistance among soil bacteria and may affect bacterial community structure and function. to investigate the effect of manure and amoxicillin added to manure on soil bacterial communities, microcosm experiments were performed with two soil types and the following treatments: (1) nontreated, (2) manure-treated, (3) treated with manure supplem ...200717991020
[changes in viability of two antarctic marine bacteria exposed to solar radiation in the water column: influence of vertical mixing].the effect of uv radiation on two antarctic marine bacterial strains (uvps and uvvi) was studied in the water column of potter cove (south shetland, antarctica). quartz flasks were filled with the bacterial suspensions and exposed to solar radiation at 0 m, 1 m and 3 m depth. assays using flasks exposed to direct solar radiation and others using flasks covered with/by interferential filters which discriminate between uva and uvb, were performed. in other assays, a vertical mixing of 4 m/h was si ...200717987855
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