| uranium reduction. | the dramatic decrease in solubility accompanying the reduction of u(vi) to u(iv), producing the insoluble mineral uraninite, has been viewed as a potential mechanism for sequestration of environmental uranium contamination. in the past 15 years, it has been firmly established that a variety of bacteria exhibit this reductive capacity. to obtain an understanding of the microbial metal metabolism, to develop a practical approach for the acceleration of in situ bioreduction, and to predict the long ... | 2006 | 16704344 |
| synthesis and structure-activity correlation studies of metal complexes of alpha-n-heterocyclic carboxaldehyde thiosemicarbazones in shewanella oneidensis. | this investigation involved the synthesis of metal complexes to test the hypothesis that structural changesand metal coordination in pyridine thiosemicarbazones affect cell growth and cell proliferation in vitro. thiosemicarbazones are well known to possess antitumor, antiviral, antibacterial, antimalarial, and other activities. extensive research has been carried out on aliphatic, aromatic, heterocyclic and other types of thiosemicarbazones and their metal complexes. due to the pronounced react ... | 2005 | 16705815 |
| differential recovery of biotinylated microbial proteins using monomeric or polymeric avidin. | | 2006 | 16708758 |
| optimization of the biological component of a bioelectrochemical cell. | the efficiency of electron transduction by shewanella oneidensis mr-1 was investigated both in batch culture and in a dual-chambered electrochemical cell. aerobically grown bacteria were inoculated into an insoluble feooh suspension in an anaerobic environment. as the bacteria reduced fe(iii) to fe(ii) there was a visible color change from red to bluish black; this simple color change assay proved to be a robust method for determining the electrochemical activity of s. oneidensis mr-1. in an eff ... | 2007 | 16713750 |
| mechanism of a soluble fumarate reductase from shewanella frigidimarina: a theoretical study. | the mechanism of a unique fumarate reductase is explored using the hybrid density functional b3lyp method. the calculations show a two-step mechanism, initiated with a hydride transfer from fad (flavin adenine dinucleotide) to fumarate, followed by a proton shift from arg402. the rate-limiting process is assigned to the hydride transfer, and the energetics are consistent with experimental data. it is shown that the enzyme is essential to correctly position the substrate in the active site, stabi ... | 2006 | 16722766 |
| evaluation of the effects of various culture conditions on cr(vi) reduction by shewanella oneidensis mr-1 in a novel high-throughput mini-bioreactor. | the growth and cr(vi) reduction by shewanella oneidensis mr-1 was examined using a mini-bioreactor system that independently monitors and controls ph, dissolved oxygen (do), and temperature for each of its 24, 10-ml reactors. independent monitoring and control of each reactor in the cassette allows the exploration of a matrix of environmental conditions known to influence s. oneidensis chromium reduction. s. oneidensis mr-1 grew in minimal medium without amino acid or vitamin supplementation und ... | 2006 | 16732598 |
| using size exclusion chromatography-rplc and rplc-cief as two-dimensional separation strategies for protein profiling. | bottom-up proteomics (analyzing peptides that result from protein digestion) has demonstrated capability for broad proteome coverage and good throughput. however, due to incomplete sequence coverage, this approach is not ideally suited to the study of modified proteins. the modification complement of a protein can best be elucidated by analyzing the intact protein. 2-de, typically coupled with the analysis of peptides that result from in-gel digestion, is the most frequently applied protein sepa ... | 2006 | 16732621 |
| a rapid mutant screening technique for detection of technetium [tc(vii)] reduction-deficient mutants of shewanella oneidensis mr-1. | microbial metal reduction forms the basis of alternate bioremediation strategies for reductive precipitation and immobilization of toxic metals such as the radionuclide technetium [tc(vii)]. a rapid mutant screening technique was developed to identify shewanella oneidensis mr-1 respiratory mutants unable to reduce tc(vii) as anaerobic electron acceptor. the tc(vii) reduction-deficient (tcr) mutant screening technique was based on the observation that wild-type s. oneidensis produced a black tc(i ... | 2006 | 16734791 |
| [phylogenetic diversity and cold-adaptive hydrolytic enzymes of culturable psychrophilic bacteria associated with sea ice from high latitude ocean, artic]. | the phylogenetic diversity of culturable psychrophilic bacteria associated with sea ice from high latitude sea (77 degrees 30'n - 81 degrees 12'n), canadian basin and greenland sea arctic, was investigated. a total of 37 psychrophilic strains were isolated using three different methods of ( i ) spread plate method: 100 microl of each dilution ice-melt sample was spreaded onto the surface of marine 2216 agar (difco laboratories, detroit, mi) and incubated for 2 to 6 weeks at 4 degrees c; ( ii ) b ... | 2006 | 16736573 |
| global transcriptome analysis of the cold shock response of shewanella oneidensis mr-1 and mutational analysis of its classical cold shock proteins. | this study presents a global transcriptional analysis of the cold shock response of shewanella oneidensis mr-1 after a temperature downshift from 30 degrees c to 8 or 15 degrees c based on time series microarray experiments. more than 700 genes were found to be significantly affected (p < or = 0.05) upon cold shock challenge, especially at 8 degrees c. the temporal gene expression patterns of the classical cold shock genes varied, and only some of them, most notably so1648 and so2787, were diffe ... | 2006 | 16740962 |
| enhanced biofilm formation and increased resistance to antimicrobial agents and bacterial invasion are caused by synergistic interactions in multispecies biofilms. | most biofilms in their natural environments are likely to consist of consortia of species that influence each other in synergistic and antagonistic manners. however, few reports specifically address interactions within multispecies biofilms. in this study, 17 epiphytic bacterial strains, isolated from the surface of the marine alga ulva australis, were screened for synergistic interactions within biofilms when present together in different combinations. four isolates, microbacterium phyllosphaer ... | 2006 | 16751497 |
| [shewanella genus bacteria isolated from the black sea water and molluscs]. | six (6) strains of bacteria isolated from the black sea water and mollusks mytilaster lineatus have been assigned to shewanella genus on the basis of phenotypical and molecular-genetic study. partial sequence of 16s rrna gene revealed 100% similarity of three of these strains to s. baltica, although they had some phenotypical differences. three more strains were genetically related to s. colwelliana and s. affinis (99-100% of 16s rrna sequences similarity), but they differed from these species a ... | 2006 | 16786624 |
| genomic analysis of carbon source metabolism of shewanella oneidensis mr-1: predictions versus experiments. | genomic sequences have been used to find the genetic foundation for carbon source metabolism in shewanella oneidensis mr-1. annotated s. oneidensis mr-1 gene products were examined for their sequence similarity to enzymes participating in pathways for utilization of carbon and energy as described in the biocyc database (http://www.biocyc.org/) or in the primary literature. a picture emerges that relegates five- and six-carbon sugars to minor roles as carbon sources, whereas multiple pathways for ... | 2006 | 16788168 |
| isolation of a high-affinity functional protein complex between omca and mtrc: two outer membrane decaheme c-type cytochromes of shewanella oneidensis mr-1. | shewanella oneidensis mr-1 is a facultatively anaerobic bacterium capable of using soluble and insoluble forms of manganese [mn(iii/iv)] and iron [fe(iii)] as terminal electron acceptors during anaerobic respiration. to assess the structural association of two outer membrane-associated c-type decaheme cytochromes (i.e., omca [so1779] and mtrc [so1778]) and their ability to reduce soluble fe(iii)-nitrilotriacetic acid (nta), we expressed these proteins with a c-terminal tag in wild-type s. oneide ... | 2006 | 16788180 |
| larval settlement of the common australian sea urchin heliocidaris erythrogramma in response to bacteria from the surface of coralline algae. | bacterial biofilms are increasingly seen as important for the successful settlement of marine invertebrate larvae. here we tested the effects of biofilms on settlement of the sea urchin heliocidaris erythrogramma. larvae settled on many surfaces including various algal species, rocks, sand and shells. settlement was reduced by autoclaving rocks and algae, and by treatment of algae with antibiotics. these results, and molecular and culture-based analyses, suggested that the bacterial community on ... | 2006 | 16794830 |
| biocatalytic dechlorination of lindane by nano-scale particles of pd(0) deposited on shewanella oneidensis. | a new approach for the removal of the pesticide lindane (gamma-hexachlorocyclohexane or gamma-hch) makes use of catalytic reduction of hch to benzene over a metal catalyst, namely pd(0). since specific surface area plays an important role in reactivity of catalysts, this study investigated the use of biopd(0), i.e. nano-scale pd(0) particles precipitated on the biomass of shewanella oneidensis, for the removal of lindane. it was demonstrated that biopd(0) has catalytic activity towards dechlorin ... | 2007 | 16797673 |
| enhancement of polyunsaturated fatty acid production by tn5 transposon in shewanella baltica. | transposon tn5 mutagenesis was used to generate random mutations in shewanella baltica mac1, a polyunsaturated fatty acid (pufa)-producing bacterium. three mutants produced 3-5 times more eicosapentaenoic acid (epa 20:5 n-3) compared to the wild type at 10 degrees c. one of the mutants produced 0.3 mg epa g(-1) when grown at high temperature (30 degrees c). moreover, 2 mg docosahexaenoic acid (dha 22:6 n-3) g(-1) was produced by s. baltica mutants at 4 degrees c. sequencing of insertion mutation ... | 2006 | 16799757 |
| reactive azo dye reduction by shewanella strain j18 143. | a bacterial isolate designated strain j18 143, originally isolated from soil contaminated with textile wastewater, was shown to reduce intensely coloured solutions of the reactive azo dye, remazol black b to colourless solutions. phylogenetic placement based on 16s rrna gene sequence homology identified the bacterium as a shewanella species. based on results from analyses of the end products of dye decoloration of remazol black b and the simpler molecule, acid orange 7, using capillary electroph ... | 2006 | 16804943 |
| evaluation of pyrrolidonyl arylamidase for the identification of nonfermenting gram-negative rods. | to evaluate the activity of pyrrolidonyl arylamidase (pyr) for the differentiation and identification of nonfermenting gram negative rods (nfgnr), 293 isolates were tested. a 24 h culture of each test organism was prepared. from this a 108-109 cfu/ml suspension was added to 0.25 ml of sterile physiologic solution. a pyr disk was then added and the test was incubated for 30 minutes at 35-37 degrees c, at environmental atmosphere. reading was done by adding 1 drop of cinnamaldehyde reagent. strain ... | 2007 | 16822636 |
| shewanella surugensis sp. nov., shewanella kaireitica sp. nov. and shewanella abyssi sp. nov., isolated from deep-sea sediments of suruga bay, japan. | six strains representing three novel species were isolated from deep-sea sediment in suruga bay, japan, at a depth of 2406-2409 m. on the basis of 16s rrna gene sequence analysis, the isolated strains, c931(t), c941(t), d943, c952, d954 and c959(t), are closely affiliated with members of the genus shewanella. the hybridization values for dna-dna relatedness between these strains and shewanella reference strains were significantly lower than that which is accepted as the phylogenetic definition o ... | 2006 | 16825637 |
| microbial selenate sorption and reduction in nutrient limited systems. | in this study, batch sorption experiments and x-ray adsorption spectroscopy (xas) were utilized to investigate selenate sorption onto shewanella putrefaciens 200r. selenate sorption was studied as a function of ph (ranging from 3 to 7), ionic strength (ranging from 0.1 to 0.001 m), and initial selenate concentration (ranging from 10 to 5000 microm) in the absence of external electron donors. the results show that the extent of selenate sorption is strongly dependent on ph and ionic strength, wit ... | 2006 | 16830542 |
| influence of sediment components on the immobilization of zn during microbial fe-(hydr)oxide reduction. | the fate of zn and other sorbed heavy metals during microbial reduction of iron oxides is different when comparing synthetic fe-(hydr)oxides and natural sediments undergoing a similar degree of iron reduction. batch experiments with the iron-reducing organism shewanella putrefaciens were conducted to examine the effects of an aqueous complexant (nitrilotriacetic acid or nta), two solid-phase complexants (kaolinite and montmorillonite), an electron carrier (anthraquinone disulfonic acid or aqds), ... | 2006 | 16830547 |
| biogenic amine formation and microbial spoilage in chilled garfish (belone belone belone)--effect of modified atmosphere packaging and previous frozen storage. | to evaluate biogenic amine formation and microbial spoilage in fresh and thawed chilled garfish. | 2006 | 16834594 |
| electrically conductive bacterial nanowires produced by shewanella oneidensis strain mr-1 and other microorganisms. | shewanella oneidensis mr-1 produced electrically conductive pilus-like appendages called bacterial nanowires in direct response to electron-acceptor limitation. mutants deficient in genes for c-type decaheme cytochromes mtrc and omca, and those that lacked a functional type ii secretion pathway displayed nanowires that were poorly conductive. these mutants were also deficient in their ability to reduce hydrous ferric oxide and in their ability to generate current in a microbial fuel cell. nanowi ... | 2006 | 16849424 |
| comparative genomics and experimental characterization of n-acetylglucosamine utilization pathway of shewanella oneidensis. | we used a comparative genomics approach implemented in the seed annotation environment to reconstruct the chitin and glcnac utilization subsystem and regulatory network in most proteobacteria, including 11 species of shewanella with completely sequenced genomes. comparative analysis of candidate regulatory sites allowed us to characterize three different glcnac-specific regulons, nagc, nagr, and nagq, in various proteobacteria and to tentatively assign a number of novel genes with specific funct ... | 2006 | 16857666 |
| ligand-induced conformational changes in the capping subdomain of a bacterial old yellow enzyme homologue and conserved sequence fingerprints provide new insights into substrate binding. | we have recently reported that shewanella oneidensis, a gram-negative gamma-proteobacterium with a rich arsenal of redox proteins, possesses four old yellow enzyme (oye) homologues. here, we report a series of high resolution crystal structures for one of these oyes, shewanella yellow enzyme 1 (sye1), in its oxidized form at 1.4a resolution, which binds a molecule of peg 400 in the active site, and in its nadh-reduced and p-hydroxybenzaldehyde- and p-hydroxyacetophenone-bound forms at 1.7a resol ... | 2006 | 16857682 |
| a phosphopantetheinyl transferase gene essential for biosynthesis of n-3 polyunsaturated fatty acids from moritella marina strain mp-1. | a phosphopantetheinyl transferase (pptase) gene (pfae), cloned from the docosahexaenoic acid (dha)-producing bacterium moritella marina strain mp-1, has an open reading frame of 861 bp encoding a 287-amino acid protein. when the pfae gene was expressed with pfaa-d, which are four out of five essential genes for biosynthesis of eicosapentaenoic acid (epa) derived from shewanella pneumatophori scrc-2738 in escherichia coli, the recombinant produced 12% epa of total fatty acids. this suggests that ... | 2006 | 16859689 |
| a kinetic model describing shewanella oneidensis mr-1 growth, substrate consumption, and product secretion. | aerobic growth of shewanella oneidensis mr-1 in minimal lactate medium was studied in batch cultivation. acetate production was observed in the middle of the exponential growth phase and was enhanced when the dissolved oxygen (do) concentration was low. once the lactate was nearly exhausted, s. oneidensis mr-1 used the acetate produced during growth on lactate with a similar biomass yield as lactate. a two-substrate monod model, with competitive and uncompetitive substrate inhibition, was devise ... | 2007 | 16865732 |
| nhad type sodium/proton-antiporter of halomonas elongata: a salt stress response mechanism in marine habitats? | sodium/proton-antiporters (nha) are known to play an important role in ph- and na+-homeostasis. in microorganisms several types with different capacity, affinity and selectivity for na+ and li+ exist. the homeostasis system of e. coli, nhaa and nhab, is well researched, but the function of other types of na+/h+-antiporters like nhad is yet to be fully understood. since several antiporters play an important role at various points in the physiology of higher organisms, one can speculate that the m ... | 2006 | 16872527 |
| c-type cytochrome-dependent formation of u(iv) nanoparticles by shewanella oneidensis. | modern approaches for bioremediation of radionuclide contaminated environments are based on the ability of microorganisms to effectively catalyze changes in the oxidation states of metals that in turn influence their solubility. although microbial metal reduction has been identified as an effective means for immobilizing highly-soluble uranium(vi) complexes in situ, the biomolecular mechanisms of u(vi) reduction are not well understood. here, we show that c-type cytochromes of a dissimilatory me ... | 2006 | 16875436 |
| ultra-sensitive and quantitative characterization of proteomes. | electrospray ionization mass spectrometry combined with high efficiency capillary liquid chromatography provides high sensitivity and broad dynamic range measurements for the characterization of biological macromolecules in complex matrices, and is an increasingly powerful analytical tool for systems biology research. | 2006 | 16880940 |
| one-step, non-denaturing isolation of an rna polymerase enzyme complex using an improved multi-use affinity probe resin. | the rapid isolation of protein complexes is critical to the goal of establishing protein interaction networks. high-throughput methods for identifying protein binding partners in a way suitable for mass spectrometric identification and structural analysis are required and small molecule/peptide interactions provide the key. we have now shown that a redesigned resin derivatized with a bisarsenical dye can be used to isolate the shewanella oneidensis rna polymerase core enzyme with a tetracysteine ... | 2005 | 16880963 |
| electronic coupling between heme electron-transfer centers and its decay with distance depends strongly on relative orientation. | a method for calculating the electron-transfer matrix element v(rp) using density functional theory kohn-sham orbitals is presented and applied to heme dimers of varying relative orientation. the electronic coupling decays with increased iron separation according to v(rp) = v(0)(rp)exp(-beta r/2) with a distance dependence parameter beta approximately 2 a(-1) for hemes with parallel porphyrins and either 1.1 or 4.0 a(-1) when the porphyrin planes are perpendicular, depending on the alignment of ... | 2006 | 16884282 |
| carbohydrate oxidation coupled to fe(iii) reduction, a novel form of anaerobic metabolism. | an isolate, designated gc-29, that could incompletely oxidize glucose to acetate and carbon dioxide with fe(iii) serving as the electron acceptor was recovered from freshwater sediments of the potomac river, maryland. this metabolism yielded energy to support cell growth. strain gc-29 is a facultatively anaerobic, gram-negative motile rod which, in addition to glucose, also used sucrose, lactate, pyruvate, yeast extract, casamino acids or h2 as alternative electron donors for fe(iii) reduction. ... | 1998 | 16887653 |
| influence of storage temperature on microbial spoilage characteristics of haddock fillets (melanogrammus aeglefinus) evaluated by multivariate quality prediction. | the proliferation of specific spoilage organisms (sso) and quality changes were evaluated in haddock fillets stored in styrofoam boxes at 0, 7 and 15 degrees c and under temperature fluctuations. a rapid electronic nose technique was used to monitor different classes of compounds, representing microbial metabolites that were characteristic for the onset of spoilage odors. photobacterium phosphoreum predominated among the spoilage bacteria and high levels of tvb-n were observed at sensory rejecti ... | 2006 | 16889858 |
| shewanella loihica sp. nov., isolated from iron-rich microbial mats in the pacific ocean. | a novel marine bacterial strain, pv-4(t), isolated from a microbial mat located at a hydrothermal vent of loihi seamount in the pacific ocean, has been characterized. this micro-organism is orangey in colour, gram-negative, polarly flagellated, facultatively anaerobic and psychrotolerant (temperature range, 0-42 degrees c). no growth was observed with nitrate, nitrite, dmso or thiosulfate as the electron acceptor and lactate as the electron donor. the major fatty acid detected in strain pv-4(t) ... | 2006 | 16902030 |
| isolation and identification of shewanella alga and its pathogenic effects on post-larvae of abalone haliotis diversicolor supertexta. | | 2006 | 16911538 |
| tale of two metal reducers: comparative proteome analysis of geobacter sulferreducens pca and shewanella oneidensis mr-1. | geobacter sulfurreducens and s. oneidensis are the subjects of intense research efforts due to their potential applications to bioremediation. the characterization of their proteomes, being done in parallel with the analysis of their genome sequences, transcriptomes, and metabolomes, is providing valuable insights to both their similarities and their differences. a primary target of interest in the proteomes of both of these metal-reducing microbes is the characterization of their c-type cytochr ... | 2006 | 16929676 |
| amt tag approach to proteomic characterization of deinococcus radiodurans and shewanella oneidensis. | | 2006 | 16929677 |
| crystallographic studies of the binding of ligands to the dicarboxylate site of complex ii, and the identity of the ligand in the "oxaloacetate-inhibited" state. | mitochondrial complex ii (succinate:ubiquinone oxidoreductase) is purified in a partially inactivated state, which can be activated by removal of tightly bound oxaloacetate (e.b. kearney, et al., biochem. biophys. res. commun. 49 1115-1121). we crystallized complex ii in the presence of oxaloacetate or with the endogenous inhibitor bound. the structure showed a ligand essentially identical to the "malate-like intermediate" found in shewanella flavocytochrome c crystallized with fumarate (p. tayl ... | 2006 | 16935256 |
| spatiometabolic stratification of shewanella oneidensis biofilms. | biofilms, or surface-attached microbial communities, are both ubiquitous and resilient in the environment. although much is known about how biofilms form, develop, and detach, very little is understood about how these events are related to metabolism and its dynamics. it is commonly thought that large subpopulations of cells within biofilms are not actively producing proteins or generating energy and are therefore dead. an alternative hypothesis is that within the growth-inactive domains of biof ... | 2006 | 16936048 |
| a biofilm enhanced miniature microbial fuel cell using shewanella oneidensis dsp10 and oxygen reduction cathodes. | a miniature-microbial fuel cell (mini-mfc, chamber volume: 1.2 ml) was used to monitor biofilm development from a pure culture of shewanella oneidensis dsp10 on graphite felt (gf) under minimal nutrient conditions. esem evidence of biofilm formation on gf is supported by substantial power density (per device cross-section) from the mini-mfc when using an acellular minimal media anolyte (1500 mw/m2). these experiments demonstrate that power density per volume for a biofilm flow reactor mfc should ... | 2007 | 16939710 |
| global molecular and morphological effects of 24-hour chromium(vi) exposure on shewanella oneidensis mr-1. | the biological impact of 24-h ("chronic") chromium(vi) [cr(vi) or chromate] exposure on shewanella oneidensis mr-1 was assessed by analyzing cellular morphology as well as genome-wide differential gene and protein expression profiles. cells challenged aerobically with an initial chromate concentration of 0.3 mm in complex growth medium were compared to untreated control cells grown in the absence of chromate. at the 24-h time point at which cells were harvested for transcriptome and proteome ana ... | 2006 | 16957260 |
| toward a more robust assessment of intraspecies diversity, using fewer genetic markers. | phylogenetic sequence analysis of single or multiple genes has dominated the study and census of the genetic diversity among closely related bacteria. it remains unclear, however, how the results based on a few genes in the genome correlate with whole-genome-based relatedness and what genes (if any) best reflect whole-genome-level relatedness and hence should be preferentially used to economize on cost and to improve accuracy. we show here that phylogenies of closely related organisms based on t ... | 2006 | 16980418 |
| atr-ftir spectroscopy reveals bond formation during bacterial adhesion to iron oxide. | the contribution of various bacterial surface functional groups to adhesion at hematite and znse surfaces was examined using attenuated total reflectance (atr) fourier transform infrared (ftir) spectroscopy. when live shewanella oneidensis, pseudomonas aeruginosa, and bacillus subtilis cells were introduced to a horizontal hematite (alpha-fe(2)o(3))-coated internal reflection element (ire), ftir peaks emerged corresponding to bacterial phosphate group binding. these ir peaks were not observed wh ... | 2006 | 16981768 |
| biological reduction of nanoengineered iron(iii) oxide sculptured thin films. | sculptured thin films (stfs) are assemblies of nominally identical, parallel nanowires with tailored shapes such as chevrons and spirals. a series of iron(lll) stfs were produced with varied crystallinity (from hematite toferrihydrite) and nanowire shapes (slanted columnar, clockwise helical, and counterclockwise helical). when the dissimilatory metal-reducing bacterium shewanella putrefaciens cn32 was used to measure their bioreducibility, it was found that bioreduction was controlled primarily ... | 2006 | 16999129 |
| a novel ice in the genome of shewanella putrefaciens w3-18-1: comparison with the sxt/r391 ice-like elements. | a novel r391-like ice (integrating conjugative element) has been detected in the 4.2 mb genome of shewanella putrefaciens w3-18-1 located on three different contigs. assembly of the ice encoding contigs based on similarity with r391 revealed a mosaic element of plasmid, phage and transposon-like sequences typical of sxt/r391 ice-like elements. the element, which is 110 057 bp in length, was highly similar to r391 sequences, with most related orfs showing >96% amino acid sequence identity. the el ... | 2006 | 17020552 |
| physiological changes induced in four bacterial strains following oxidative stress. | in order to study the behaviour and resistance of bacteria under extreme conditions, physiological changes associated with oxidative stress were monitored using flow cytometry. the study was conducted to assess the maintenance of membrane integrity and potential as well as the esterase activity, the intracellular ph and the production of superoxide anions in four bacterial strains (ralstonia metallidurans, escherichia coli, shewanella oneidensis and deinococcus radiodurans). the strains were cho ... | 2006 | 17022450 |
| biological control of the size and reactivity of catalytic pd(0) produced by shewanella oneidensis. | the interaction between shewanella oneidensis mr-1 and the soluble metal pd(ii) during the reductive precipitation of pd(0) determined the size and properties of the precipitated pd(0) nanoparticles. assessment of cell viability indicated that the bioreduction of pd(ii) was a detoxification mechanism depending on the pd(ii) concentration and on the presence and properties of the electron donor. the addition of h(2) in the headspace allowed s. oneidensis to resist the toxic effects of pd(ii). int ... | 2006 | 17033880 |
| [the effects of the humic substances on azoreduction by shewanella spp]. | under anaerobic conditions, shewanella cinicad14(t), shewanella baltica and shewane-lla putrefaciens are capable of high-rate azoreduction and humus reduction. the results indicated that at low concentration ( <2 mmol/l) aqs was a accelerator for bacterial azoreduction. however, when the concentration of aqs was more than 5 mmol/l a strong inhibition was occurred. on the other hand, the concentration of aqds as high as 12 mmol/l the inhibition of azoreduction was still not exhibited, but the eff ... | 2006 | 17037061 |
| predicting gene expression level from codon usage bias. | the "expression measure" of a gene, e(g), is a statistic devised to predict the level of gene expression from codon usage bias. e(g) has been used extensively to analyze prokaryotic genome sequences. we discuss 2 problems with this approach. first, the formulation of e(g) is such that genes with the strongest selected codon usage bias are not likely to have the highest predicted expression levels; indeed the correlation between e(g) and expression level is weak among moderate to highly expressed ... | 2007 | 17038449 |
| effects of electron donors and acceptors on anaerobic reduction of azo dyes by shewanella decolorationis s12. | shewanella decolorationis s12 was able to reduce various azo dyes in a defined medium with formate, lactate, and pyruvate or h(2) as electron donors under anaerobic conditions. purified membranous, periplasmic, and cytoplasmic fractions from strain s12 analyzed, respectively, only membranous fraction was capable of reducing azo dye in the presence of electron donor, indicating that the enzyme system for anaerobic azoreduction was located on cellular membrane. respiratory inhibitor cu(2+), dicuma ... | 2007 | 17043816 |
| simultaneous microbial reduction of iron(iii) and arsenic(v) in suspensions of hydrous ferric oxide. | bacterial reduction of arsenic(v) and iron(iii) oxides influences the redox cycling and partitioning of arsenic (as) between solid and aqueous phases in sediment-porewater systems. two types of anaerobic bacterial incubations were designed to probe the relative order of as(v) and fe(iii) oxide reduction and to measure the effect of adsorbed as species on the rate of iron reduction, using hydrous ferric oxide (hfo) as the iron substrate. in one set of experiments, hfo was pre-equilibrated with as ... | 2006 | 17051784 |
| mercury methylation by dissimilatory iron-reducing bacteria. | the hg-methylating ability of dissimilatory iron-reducing bacteria in the genera geobacter, desulfuromonas, and shewanella was examined. all of the geobacter and desulfuromonas strains tested methylated mercury while reducing fe(iii), nitrate, or fumarate. in contrast, none of the shewanella strains produced methylmercury at higher levels than abiotic controls under similar culture conditions. geobacter and desulfuromonas are closely related to known hg-methylating sulfate-reducing bacteria with ... | 2006 | 17056699 |
| high-affinity binding and direct electron transfer to solid metals by the shewanella oneidensis mr-1 outer membrane c-type cytochrome omca. | the purified outer membrane bacterial protein omca binds densely to the surface of hematite (fe2o3), permitting direct electron transfer to this solid mineral to reduce fe (iii) with an electron flux of about 1013 electrons /cm2/s. in the presence of hematite, there is a substantial increase in the amplitude of internal protein motions that correlate with metal reduction. binding is highly favorable, with a partition coefficient of approximately 2 x 105 (deltago' = -28 kj/mol), where approximate ... | 2006 | 17061851 |
| the bacterial species definition in the genomic era. | the bacterial species definition, despite its eminent practical significance for identification, diagnosis, quarantine and diversity surveys, remains a very difficult issue to advance. genomics now offers novel insights into intra-species diversity and the potential for emergence of a more soundly based system. although we share the excitement, we argue that it is premature for a universal change to the definition because current knowledge is based on too few phylogenetic groups and too few samp ... | 2006 | 17062412 |
| atomic force microscopy of microbial cells: application to nanomechanical properties, surface forces and molecular recognition forces. | in recent years, the physical properties and interaction forces of microbial cell surfaces have been extensively studied using atomic force microscopy (afm). a variety of afm force spectroscopy approaches have been developed for investigating native cell surfaces with piconewton (nanonewton) sensitivity and nanometer lateral resolution, providing novel information on the nanomechanical properties of cell walls, on surface forces such as van der waals and electrostatic forces, solvation and steri ... | 2007 | 17067786 |
| mediating electron transfer from bacteria to a gold electrode via a self-assembled monolayer. | numerous bacterial genera are known to respire anaerobically using macroscopic electrodes as electron acceptors. typically, inexpensive graphite electrodes, which are readily colonized, are used to monitor electrogenic bacterial metabolism for microbial fuel cell and bioelectronics studies. we compare current production by electrogenic bacteria on gold electrodes coated with various alkanethiol self-assembled monolayers to current production on glassy carbon electrodes. current production is cor ... | 2006 | 17073464 |
| respiration and growth of shewanella decolorationis s12 with an azo compound as the sole electron acceptor. | the ability of shewanella decolorationis s12 to obtain energy for growth by coupling the oxidation of various electron donors to dissimilatory azoreduction was investigated. this microorganism can reduce a variety of azo dyes by use of formate, lactate, pyruvate, or h(2) as the electron donor. furthermore, strain s12 grew to a maximal density of 3.0 x 10(7) cells per ml after compete reduction of 2.0 mm amaranth in a defined medium. this was accompanied by a stoichiometric consumption of 4.0 mm ... | 2007 | 17085710 |
| respiratory nitrate ammonification by shewanella oneidensis mr-1. | anaerobic cultures of shewanella oneidensis mr-1 grown with nitrate as the sole electron acceptor exhibited sequential reduction of nitrate to nitrite and then to ammonium. little dinitrogen and nitrous oxide were detected, and no growth occurred on nitrous oxide. a mutant with the napa gene encoding periplasmic nitrate reductase deleted could not respire or assimilate nitrate and did not express nitrate reductase activity, confirming that the napa enzyme is the sole nitrate reductase. hence, s. ... | 2007 | 17098906 |
| microarray-based analysis of microbial community rnas by whole-community rna amplification. | a new approach, termed whole-community rna amplification (wcra), was developed to provide sufficient amounts of mrnas from environmental samples for microarray analysis. this method employs fusion primers (six to nine random nucleotides with an attached t7 promoter) for the first-strand synthesis. the shortest primer (t7n6s) gave the best results in terms of the yield and representativeness of amplification. about 1,200- to 1,800-fold amplification was obtained with amounts of the rna templates ... | 2007 | 17098911 |
| shewanella oneidensis mr-1 fluxome under various oxygen conditions. | the central metabolic fluxes of shewanella oneidensis mr-1 were examined under carbon-limited (aerobic) and oxygen-limited (microaerobic) chemostat conditions, using 13c-labeled lactate as the sole carbon source. the carbon labeling patterns of key amino acids in biomass were probed using both gas chromatography-mass spectrometry (gc-ms) and 13c nuclear magnetic resonance (nmr). based on the genome annotation, a metabolic pathway model was constructed to quantify the central metabolic flux distr ... | 2007 | 17098921 |
| new violet 3,3'-bipyridyl pigment purified from deep-sea microorganism shewanella violacea dss12. | we have purified a new violet pigment derived from shewanella violacea dss12 to determine its chemical structure. the pigment colored blue in tetrahydrofuran (thf) or chloroform and showed a broad absorption spectrum from 500 to 700 nm. x-ray diffraction analysis of single crystals showed that the chemical structure of this pigment was 5,5'-didodecylamino-4,4'-dihydroxy-3,3'-diazodiphenoquinone-(2,2'), containing the same chromophore as an indigoidine known as microbial blue pigment. the violet ... | 2007 | 17102923 |
| anaerobic central metabolic pathways in shewanella oneidensis mr-1 reinterpreted in the light of isotopic metabolite labeling. | it has been proposed that during growth under anaerobic or oxygen-limited conditions, shewanella oneidensis mr-1 uses the serine-isocitrate lyase pathway common to many methylotrophic anaerobes, in which formaldehyde produced from pyruvate is condensed with glycine to form serine. the serine is then transformed through hydroxypyruvate and glycerate to enter central metabolism at phosphoglycerate. to examine its use of the serine-isocitrate lyase pathway under anaerobic conditions, we grew s. one ... | 2007 | 17114268 |
| genes that enhance the ecological fitness of shewanella oneidensis mr-1 in sediments reveal the value of antibiotic resistance. | environmental bacteria persist in various habitats, yet little is known about the genes that contribute to growth and survival in their respective ecological niches. signature-tagged mutagenesis (stm) of shewanella oneidensis mr-1 coupled with a screen involving incubations of mutant strains in anoxic aquifer sediments allowed us to identify 47 genes that enhance fitness in sediments. gene functions inferred from annotations provide us with insight into physiological and ecological processes tha ... | 2007 | 17114320 |
| multiscale dynamics of the cell envelope of shewanella putrefaciens as a response to ph change. | the bacterial surface properties of gram-negative shewanella putrefaciens were characterized by microbial adhesion to hydrocarbons (math), adhesion to polystyrene dishes, and electrophoresis at different values of ph and ionic strength. the bacterial adhesion to these two apolar substrates shows significant variations according to ph and ionic strength. such behavior could be partly explained by electrostatic repulsions between bacteria and the solid or liquid interface. however, a similar trend ... | 2006 | 17120322 |
| kinetics of microbial reduction of solid phase u(vi). | sodium boltwoodite (nauo2sio3oh x 1.5 h2o) was used to assess the kinetics of microbial reduction of solid-phase u(vi) by a dissimilatory metal-reducing bacterium (dmrb), shewanella oneidensis strain mr-1. the bioreduction kinetics was studied with na-boltwoodite in suspension or within alginate beads in a nongrowth medium with lactate as electron donor at ph 6.8 buffered with pipes. concentrations of u(vi)tot and cell number were varied to evaluate the coupling of u(vi) dissolution, diffusion, ... | 2006 | 17120555 |
| bacterial genes responsible for the biosynthesis of eicosapentaenoic and docosahexaenoic acids and their heterologous expression. | | 2007 | 17122401 |
| analysis of bacteria degradation products of methyl parathion by liquid chromatography/electrospray time-of-flight mass spectrometry and gas chromatography/mass spectrometry. | the biodegradation of the organophosphorus insecticide methyl parathion (mp) in aqueous environment by bacteria isolated from river sediment has been studied. two species of bacteria which show strong mp degradation ability are identified as shewanella and vibrio parahaemolyticus. the biodegradation of mp proceeded rapidly with the formation of a series of intermediate products, which were analyzed using a combination of gc/ms and hplc/esi-tofms techniques. the major products tentatively identif ... | 2006 | 17126847 |
| enrichment of functional redox reactive proteins and identification by mass spectrometry results in several terminal fe(iii)-reducing candidate proteins in shewanella oneidensis mr-1. | identification of the proteins directly involved in microbial metal-reduction is important to understanding the biochemistry involved in heavy metal-reduction/immobilization and the ultimate cleanup of doe contaminated sites. although previous strategies for the identification of these proteins have traditionally required laborious protein purification/characterization of metal-reducing capability, activity is often lost before the final purification step, thus creating a significant knowledge g ... | 2007 | 17137661 |
| mixed-valence cytoplasmic iron granules are linked to anaerobic respiration. | intracellular granules containing ferric and ferrous iron formed in shewanella putrefaciens cn32 during dissimilatory reduction of solid-phase ferric iron. it is the first in situ detection at high resolution (150 nm) of a mixed-valence metal particle residing within a prokaryotic cell. the relationship of the internal particles to fe(iii) reduction may indicate a respiratory role. | 2007 | 17142380 |
| a conserved histidine in cytochrome c maturation permease ccmb of shewanella putrefaciens is required for anaerobic growth below a threshold standard redox potential. | shewanella putrefaciens strain 200 respires a wide range of compounds as terminal electron acceptor. the respiratory versatility of shewanella is attributed in part to a set of c-type cytochromes with widely varying midpoint redox potentials (e'(0)). a point mutant of s. putrefaciens, originally designated urr14 and here renamed ccmb1, was found to grow at wild-type rates on electron acceptors with high e'0 [o2, no3-, fe(iii) citrate, mno2, and mn(iii) pyrophosphate] yet was severely impaired fo ... | 2007 | 17142390 |
| novel reduction of mercury (ii) by mercury-sensitive dissimilatory metal reducing bacteria. | the dissimilatory metal reducing bacterium (dmrb) shewanella oneidensis mr-1 reduces ionic mercury (hg[ii]) to elemental mercury (hg[0]) by an activity not related to the mera mercuric reductase. in s. oneidensis, this activity is constitutive and effective at hg(ii) concentrations too low to induce mer operon functions. reduction of hg(ii) by mr-1 required the presence of electron donors and electron acceptors. reduction occurred with oxygen or fumarate, but had the highest rate when ferric oxy ... | 2006 | 17144297 |
| contrasting effects of dissimilatory iron (iii) and arsenic (v) reduction on arsenic retention and transport. | reduction of arsenate as(v) and as-bearing fe (hydr)- oxides have been proposed as dominant pathways of as release within soils and aquifers. here we examine as elution from columns loaded with ferrihydrite-coated sand presorbed with as(v) or as(iii) at circumneutral ph upon fe and/or as reduction; biotic stimulated reduction is then compared to abiotic elution. columns were inoculated with shewanella putrefaciens strain cn-32 or sulfurospirillum barnesii strain ses-3, organisms capable of as (v ... | 2006 | 17144301 |
| acute exudative tonsillitis caused by shewanella algae in a healthy child. | shewanella algae, mainly found in marine environments, is a rare pathogen in humans, especially in healthy children. here we report a previously healthy boy presenting with acute exudative tonsillitis after traveling to the coast, and s. algae was isolated from the throat swab culture. | 2006 | 17148087 |
| shewanella irciniae sp. nov., a novel member of the family shewanellaceae, isolated from the marine sponge ircinia dendroides in the bay of villefranche, mediterranean sea. | strain ust040317-058(t), comprising non-pigmented, rod-shaped, facultatively anaerobic, gram-negative cells that are motile by means of single polar flagella, was isolated from the surface of a marine sponge (ircinia dendroides) collected from the mediterranean sea. comparative 16s rrna gene sequence-based phylogenetic analysis placed the strain in a separate cluster with the recognized bacterium shewanella algae iam 14159(t), with which it showed a sequence similarity of 95.0 %. the sequence si ... | 2006 | 17158990 |
| shewanella spongiae sp. nov., isolated from a marine sponge. | a psychrophilic bacterium, designated strain hj039(t), was isolated from a marine sponge collected in the east sea of korea (also known as the sea of japan). cells were gram-negative, motile and rod-shaped (1.8-3.54 microm x 0.27-0.73 microm). growth was observed between 5 and 26 degrees c (optimum 15 degrees c), at ph 5.0-8.5 (optimum ph 6.0-6.5) and in the presence of 0-6.0 % nacl (optimum 2.0 %). the 16s rrna gene sequence of strain hj039(t) showed high levels of similarity (93.7-95.4 %) with ... | 2006 | 17158991 |
| necrotizing fasciitis caused by shewanella putrefaciens in a uremic patient. | shewanella putrefaciens rarely causes infections in humans. this report describes a case of necrotizing fasciitis caused by s. putrefaciens in a uremic patient who recovered in spite of inadequate antibiotic treatment. s. putrefaciens is a possible causative organism of necrotizing fasciitis, and the absence of any sign of systemic infection cannot rule out the possibility of invasive infection in uremic patients. surgical intervention is important in such cases. | 2006 | 17164955 |
| bacterial adaptation to high pressure: a respiratory system in the deep-sea bacterium shewanella violacea dss12. | shewanella violacea dss12 is a psychrophilic facultative piezophile isolated from the deep sea. in a previous study, we have shown that the bacterium adapted its respiratory components to alteration in growth pressure. this appears to be one of the bacterial adaptation mechanisms to high pressures. in this study, we measured the respiratory activities of s. violacea grown under various pressures. there was no significant difference between the cells grown under atmospheric pressure and a high pr ... | 2007 | 17166225 |
| process of maturation of tetraheme cytochrome c3 in a shewanella expression system. | the process of maturation of multiheme proteins is not yet well known, while that of monoheme ones has been relatively well investigated. two kinds of partly unfolded tetraheme cytochrome c3 were obtained on overexpression in shewanella oneidensis tsp-c. these proteins were characterized by circular dichroism and nuclear magnetic resonance spectroscopy. it turned out that the tetraheme architecture, and the fifth and sixth ligand coordination are almost mature, while some parts of the polypeptid ... | 2007 | 17167041 |
| lateral transfer of the lux gene cluster. | the lux operon is an uncommon gene cluster. to find the pathway through which the operon has been transferred, we sequenced the operon and both flanking regions in four typical luminous species. in vibrio cholerae ncimb 41, a five-gene cluster, most genes of which were highly similar to orthologues present in gram-positive bacteria, along with the lux operon, is inserted between vc1560 and vc1563, on chromosome 1. because this entire five-gene cluster is present in photorhabdus luminescens tt01, ... | 2007 | 17169972 |
| bioreductive deposition of platinum nanoparticles on the bacterium shewanella algae. | an environmentally friendly method using the metal ion-reducing bacterium shewanella algae was proposed to deposit platinum nanoparticles. resting cells of s. algae were able to reduce aqueous ptcl(6)(2-) ions into elemental platinum at room temperature and neutral ph within 60min when lactate was provided as the electron donor. biogenic platinum nanoparticles of about 5nm were located in the periplasm--a preferable, cell surface location for easy recovery of biogenic nanoparticles. | 2007 | 17182148 |
| culturable and vbnc vibrio cholerae: interactions with chironomid egg masses and their bacterial population. | vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments. recently, it was found that chironomid (nonbiting midges) egg masses serve as a reservoir for the cholera bacterium and that flying chironomid adults are possible windborne carriers of v. cholerae non-o1 non-o139. chironomids are the most widely distributed insect in freshwater. females deposit egg masses at the water's edge, and each egg mass contains eggs embedded in a gelatinous matrix. hemagglu ... | 2007 | 17186156 |
| the pio operon is essential for phototrophic fe(ii) oxidation in rhodopseudomonas palustris tie-1. | phototrophic fe(ii)-oxidizing bacteria couple the oxidation of ferrous iron [fe(ii)] to reductive co(2) fixation by using light energy, but until recently, little has been understood about the molecular basis for this process. here we report the discovery, with rhodopseudomonas palustris tie-1 as a model organism, of a three-gene operon, designated the pio operon (for phototrophic iron oxidation), that is necessary for phototrophic fe(ii) oxidation. the first gene in the operon, pioa, encodes a ... | 2007 | 17189359 |
| hydrogen metabolism in shewanella oneidensis mr-1. | shewanella oneidensis mr-1 is a facultative sediment microorganism which uses diverse compounds, such as oxygen and fumarate, as well as insoluble fe(iii) and mn(iv) as electron acceptors. the electron donor spectrum is more limited and includes metabolic end products of primary fermenting bacteria, such as lactate, formate, and hydrogen. while the utilization of hydrogen as an electron donor has been described previously, we report here the formation of hydrogen from pyruvate under anaerobic, s ... | 2007 | 17189435 |
| characterisation of the dominant bacterial population in modified atmosphere packaged farmed halibut (hippoglossus hippoglossus) based on 16s rdna-dgge. | it is not well understood why atlantic halibut (hippoglossus hippoglossus) has longer shelf-life than most other white fish species. our approach was to examine the microbiological diversity of the spoilage microbiota during modified atmosphere (ma) packaging of farmed atlantic halibut. portions were packaged with gas mixtures of co(2):n(2) and co(2):o(2) (50%:50%) and with air as a reference. the packages were stored at 4 degrees c and samples were taken 6 times during the 23 days of storage. a ... | 2007 | 17189762 |
| transposon tn7 is widespread in diverse bacteria and forms genomic islands. | we find that relatives of the bacterial transposon tn7 are widespread in disparate environments and phylogenetically diverse species. these elements form functionally diverse genomic islands at the specific site of tn7 insertion adjacent to glms. this work presents the first example of genomic island formation by a dde type transposon. | 2007 | 17194796 |
| molecular insights into substrate recognition and catalysis by tryptophan 2,3-dioxygenase. | tryptophan 2,3-dioxygenase (tdo) and indoleamine 2,3-dioxygenase (ido) constitute an important, yet relatively poorly understood, family of heme-containing enzymes. here, we report extensive structural and biochemical studies of the xanthomonas campestris tdo and a related protein so4414 from shewanella oneidensis, including the structure at 1.6-a resolution of the catalytically active, ferrous form of tdo in a binary complex with the substrate l-trp. the carboxylate and ammonium moieties of try ... | 2007 | 17197414 |
| terminal electron acceptors influence the quantity and chemical composition of capsular exopolymers produced by anaerobically growing shewanella spp. | bacterial exopolymers perform various roles, including acting as a carbon sink, a protective layer against desiccation or antimicrobial agents, or a structural matrix in biofilms. despite such varied roles, little is known about the heterogeneity of bacterial exopolymer production under varying growth conditions. here we describe experiments designed to characterize the quantity and quality of exopolymers produced by two commonly studied members of the widely distributed genus shewanella. electr ... | 2007 | 17206803 |
| the cyma gene, encoding a tetraheme c-type cytochrome, is required for arsenate respiration in shewanella species. | in shewanella sp. strain ana-3, utilization of arsenate as a terminal electron acceptor is conferred by a two-gene operon, arrab, which lacks a gene encoding a membrane-anchoring subunit for the soluble arrab protein complex. analysis of the genome sequence of shewanella putrefaciens strain cn-32 showed that it also contained the same arrab operon with 100% nucleotide identity. here, we report that cn-32 respires arsenate and that this metabolism is dependent on arra and an additional gene encod ... | 2007 | 17209025 |
| fe(iii)-enhanced azo reduction by shewanella decolorationis s12. | shewanella decolorationis s12 is capable of high rates of azo dye decolorization and dissimilatory fe(iii) reduction. under anaerobic conditions, when fe(iii) and azo dye were copresent in s12 cultures, dissimilatory fe(iii) reduction and azo dye biodecolorization occurred simultaneously. furthermore, the dye decolorization was enhanced by the presence of fe(iii). when 1 mm fe(iii) was added, the methyl red decolorizing efficiency was 72.1% after cultivation for 3 h, whereas the decolorizing eff ... | 2007 | 17216448 |
| shewanella psychrophila sp. nov. and shewanella piezotolerans sp. nov., isolated from west pacific deep-sea sediment. | two shewanella-like bacterial strains, wp2(t) and wp3(t), which were isolated from west pacific deep-sea sediment, were studied to determine their taxonomic position. cells of the two bacteria were facultatively anaerobic, gram-negative rods and motile by means of a single polar flagellum. strain wp2(t) was psychrophilic, growing optimally at about 10-15 degrees c, whereas strain wp3(t) was psychrotolerant, growing optimally at 15-20 degrees c. the two strains grew in the pressure range 0.1-50 m ... | 2007 | 17220442 |
| microspe-nanolc-esi-ms/ms using 10-microm-i.d. silica-based monolithic columns for proteomics. | silica-based monolithic capillary columns (25 cm x 10 microm i.d.) with integrated nanoesi emitters have been developed to provide high-quality and robust microspe-nanolc-esi-ms analyses. the integrated nanoesi emitter adds no dead volume to the lc separation, allowing stable electrospray operation at flow rates of approximately 10 nl/min. in an initial application with a linear ion trap ms, we identified 5510 unique peptides that covered 1443 distinct shewanella oneidensis proteins from a 300-n ... | 2007 | 17222018 |
| combined spectroscopic and topographic characterization of nanoscale domains and their distributions of a redox protein on bacterial cell surfaces. | redox protein nanoscale domains on the cell surface of a bacterium, shewanella oneidensis mr1, grown in the absence and presence of electron acceptors, is topographically characterized using combined atomic force microscopy (afm) and confocal surface enhanced raman scattering (sers) spectroscopy. the protruding nanoscale domains on the outer membrane of s. oneidensis were observed, as was their disappearance upon exposure to electron acceptors such as oxygen, nitrate, fumarate, and iron nitrilot ... | 2007 | 17241055 |
| extracellular synthesis of magnetite and metal-substituted magnetite nanoparticles. | we have developed a novel microbial process that exploits the ability of fe(iii)-reducing microorganisms to produce copious amounts of extracellular magentites and metal-substituted magnetite nanoparticles. the fe(iii)-reducing bacteria (theroanaerobacter ethanolicus and shewanella sp.) have the ability to reduce fe(iii) and various metals in aqueous media and form various sized magnetite and metal-substituted magnetite nano-crystals. the fe(iii)-reducing bacteria formed metalsubstituted magneti ... | 2006 | 17252802 |
| quantifying constraints imposed by calcium and iron on bacterial reduction of uranium(vi). | uranium is a redox active contaminant of concern to both human health and ecological preservation. in anaerobic soils and sediments, the more mobile, oxidized form of uranium (uo(2)(2+) and associated species) may be reduced by dissimilatory metal-reducing bacteria. despite rapid reduction in controlled, experimental systems, various factors within soils or sediments may limit biological reduction of u(vi), inclusive of competing electron acceptors and alterations in uranyl speciation. here we e ... | 2007 | 17255623 |
| reduction and partial degradation mechanisms of naphthylaminesulfonic azo dye amaranth by shewanella decolorationis s12. | reduction and biodegradation mechanisms of naphthylaminesulfonic azo dye amaranth using a newly isolated shewanella decolorationis strain s12 were investigated. under anaerobic conditions, amaranth was reduced by strain s12, and a stoichiometric amount of two reduction products rp-1 and rp-2 were generated. uv/visible spectrophotometric and high performance liquid chromatography (hplc) analysis indicated that rp-1 and rp-2 were 1-aminenaphthylene -4-sulfonic acid and 1-aminenaphthylene-2-hydroxy ... | 2007 | 17260140 |
| phosphate imposed limitations on biological reduction and alteration of ferrihydrite. | biogeochemical transformation (inclusive of dissolution) of iron (hydr)oxides resulting from dissimilatory reduction has a pronounced impact on the fate and transport of nutrients and contaminants in subsurface environments. despite the reactivity noted for pristine (unreacted) minerals, iron (hydr)oxides within native environments will likely have a different reactivity owing in part to changes in surface composition. accordingly, here we explore the impact of surface modifications induced by p ... | 2007 | 17265943 |
| toxicity of cr(lll) to shewanella sp. strain mr-4 during cr(vi) reduction. | bioremediation of chromium through the reduction of hexavalent chromium (as the chromate ion, cro42-) is based on the notion that the product, trivalent chromium (cr(iii)), is less toxic than chromate. in this study, we show that soluble cr(iii), present at ph 6-8 as the cr3+ ion and/or hydroxyl complexes (henceforth referred to as uncomplexed cr(iii)), can be found transiently in significant concentrations and has a deleterious effect on shewanella sp. mr-4. however, cr(lll) complexed to an org ... | 2007 | 17265950 |
| shewanella donghaensis sp. nov., a psychrophilic, piezosensitive bacterium producing high levels of polyunsaturated fatty acid, isolated from deep-sea sediments. | a gram-negative, motile, rod-shaped, psychrophilic bacterium, lt17t, was isolated from deep-sea sediments (3300 m depth) of the east sea (sea of japan). optimal growth of lt17t requires the presence of 2.5 % (w/v) nacl, a ph of 7.0-7.5 and a temperature of 17 degrees c. the isolate grows optimally under a hydrostatic pressure of 10 mpa and growth is possible between 0.1 and <30 mpa. the novel strain is positive in tests for catalase, oxidase, lipase, beta-glucosidase and gelatinase activities an ... | 2007 | 17267951 |