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humics as an electron donor for anaerobic respiration.the possibility that microorganisms might use reduced humic substances (humics) as an electron donor for the reduction of electron acceptors with a more positive redox potential was investigated. all of the fe(iii)- and humics-reducing microorganisms evaluated were capable of oxidizing reduced humics and/or the reduced humics analogue anthrahydroquinone-2,6,-disulphonate (ahods), with nitrate and/or fumarate as the electron acceptor. these included geobacter metallireducens, geobacter sulphurred ...199911207721
the evolutionary history of chromosomal super-integrons provides an ancestry for multiresistant integrons.integrons are genetic elements that acquire and exchange exogenous dna, known as gene cassettes, by a site-specific recombination mechanism. characterized gene cassettes consist of a target recombination sequence (attc site) usually associated with a single open reading frame coding for an antibiotic resistance determinant. the affiliation of multiresistant integrons (mris), which contain various combinations of antibiotic resistance gene cassettes, with transferable elements underlies the rapid ...200111209061
adhesion of the dissimilatory fe(iii)-reducing bacterium shewanella alga bry to crystalline fe(iii) oxides.shewanella alga bry adhesion to hydrous ferric oxide, goethite, and hematite was examined. adhesion to each oxide followed the langmuir adsorption model. no correlation between adhesion and fe(iii) oxide surface area or crystallinity was observed. zeta potential measurements suggested that electrostatic interactions do not influence s. alga bry adhesion to these minerals. cell adhesion does not appear to explain the recalcitrance of crystalline fe(iii) oxides to bacterial reduction.200111270646
a simple, rapid, and highly efficient gene expression system for multiheme cytochromes c.the genes of tetraheme cytochrome c3 and hexadecaheme high-molecular-weight cytochrome c from desulfovibrio vulgaris could be overexpressed as holoproteins in shewanella oneidensis tsp-c using puc-type vectors of e. coli. surprisingly, s. oneidensis was transformed directly by puc-type vectors through electroporation. the yields of the recombinant proteins in this expression system were much higher than the previously reported ones.200111272827
isolation of the rpod gene encoding the principal sigma factor of the deep-sea piezophilic bacterium shewanella violacea strain dss12 and its overexpression in escherichia coli.the gene encoding the principal a factor (rpod) of the piezophilic bacterium shewanella violacea was cloned and sequenced. the rpod gene was found to encode a polypeptide consisting of 614 amino acid residues, showing 75.6 and 64.3% identity to those of escherichia coli and pseudomonas putida, respectively. comparison with e. coli sigma70 and p. putida sigma70 showed that significant similarity exists in four conserved regions known to be required for promoter recognition and core binding. using ...200111272828
prevalence of nonfermenters in clinical specimens.one hundred and thirty three non fermenting gram negative bacilli isolated out of 625 different clinical specimens were identified and characterised. samples were exudate from chronic suppractive otits media (341), diabetic foot (117) wound (116) and blood (51). of these isolates pseudomonas aeruginosa 105(78.94%) predominated followed by acinetobacter sp 8 [6.1%], pseudomonas putrifaciens 6(4.5%), flavobacterium sp 6(4.5%), xanthomonas maltophilia 5(3.75%), alkaligenes sp 3 (2.25). 31 (23.30%) ...200011227617
[alteromona putrefaciens pleural empyema]. 200011213587
probing the active site of l-aspartate oxidase by site-directed mutagenesis: role of basic residues in fumarate reduction.l-aspartate oxidase is a very particular oxidase which behaves as a fumarate reductase in anaerobic conditions. its primary and tertiary structures present remarkable similarity with the soluble fumarate reductase (frd) from shewanella frigidimarina and the flavin subunit of the membrane-bound fumarate reductase from escherichia coli and wolinella succinogenes. this and other extensive similarities are consistent with the idea that a common catalytic mechanism for the reduction of fumarate opera ...200111294641
nmr structure of the haem core of a novel tetrahaem cytochrome isolated from shewanella frigidimarina: identification of the haem-specific axial ligands and order of oxidation.the tetrahaem cytochrome isolated during anaerobic growth of shewanella frigidimarina ncimb400 is a small protein (86 residues) involved in electron transfer to fe(iii), which can be used as a terminal respiratory oxidant by this bacterium. a 3d solution structure model of the reduced form of the cytochrome has been determined using nmr data in order to determine the relative orientation of the haems. the haem core architecture of s. frigidimarina tetrahaem cytochrome differs from that found in ...200111231004
biodiversity and horizontal gene transfer in culturable bacteria isolated from activated sludge enriched in nonylphenol ethoxylates.one hundred and twenty bacterial isolates, from activated sludge of a treatment plant collecting wastes enriched in ethoxylated nonylphenols, were studied. sixty isolates were selected on rich medium and 60 on mineral medium containing two nonylphenol ethoxylates as the sole carbon source. analysis of biodiversity at the species level was performed by comparing the alui restriction patterns of the 16s ribosomal dna amplified by pcr from 120 isolates. the rdna restriction analysis enabled us to c ...200111281319
growth and metabolic activity of shewanella putrefaciens maintained under different co2 and o2 concentrations.growth, trimethylamine (tma), off-odour and biogenic amine production by a strain of shewanella putrefaciens isolated from spoiled hake (merlucius merluccius l.) and cultured in a model system, were tested under four different gas compositions (60% co2/40% o2, 60% co2/15% o2/25% n2, 40% co2/60% o2, 40% co2/40% o2/20% n2) and under air. after 3 weeks of incubation, the control (air) batch showed the highest microbial counts (> 9 log cfu/ml) and tma concentrations (45 mg n-tma/100 ml), and strong ...200111294349
correlation between phylogenetic structure and function: examples from deep-sea shewanella.the genus shewanella is one of the typical deep-sea bacterial genera. two isolated deep-sea shewanella species, shewanella benthica and shewanella violacea, were found to be able to grow better under high hydrostatic pressure conditions than at atmospheric pressure. these species are not only piezophilic (barophilic), but also psychrophilic. many psychrophilic and psychrotolerant shewanella species have been isolated and characterized from cold environments, such as seawater in antarctica or the ...200111311432
shewanella putrefaciens adhesion and biofilm formation on food processing surfaces.laboratory model systems were developed for studying shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. s. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. s. putrefaciens bacteria suspended in buffer adhered readily to stainless steel surfaces. maximum numbers of adherent bacteria per square centimeter were reached in 8 h at 25 degrees c and reflected the cell density in suspension. numbers of ad ...200111319118
phylogenetic characterization of epibiotic bacteria in the accessory nidamental gland and egg capsules of the squid loligo pealei (cephalopoda:loliginidae).sexually mature female squid loligo pealei harbour dense bacterial communities in their accessory nidamental glands (angs) and in their egg capsules (ecs). this study describes a molecular approach using the 16s rrna gene (rdna) to identify bacterial populations within the ang and the ecs of the north atlantic squid species l. pealei. fluorescent in situ hybridization (fish) and 16s rdna analysis showed that predominantly alpha- and, to a lesser extent, gamma-proteobacteria were the predominant ...200111321532
uptake of choline from salmon flesh and its conversion to glycine betaine in response to salt stress in shewanella putrefaciens.when cultured in m63 minimal medium plus 0.6 m nacl, the growth of shewanella putrefaciens was strongly inhibited. the addition of an extract from smoked salmon to this medium restored the growth almost to the unstressed level. a comparison of the 13c nmr spectra of intracellular solutes extracted from s. putrefaciens cells cultured in both conditions revealed the accumulation of glycine betaine (gb) from the smoked salmon extract (sse). analysis of the osmoprotective properties of this extract ...200111322705
microbially catalyzed nitrate-dependent oxidation of biogenic solid-phase fe(ii) compounds.the potential for microbially catalyzed no3(-)-dependent oxidation of solid-phase fe(ii) compounds was examined using a previously described autotrophic, denitrifying, fe(ii)-oxidizing enrichment culture. the following solid-phase fe(ii)-bearing minerals were considered: microbially reduced synthetic goethite, two different end products of microbially hydrous ferric oxide (hfo) reduction (biogenic fe3o4 and biogenic feco3), chemically precipitated feco3, and two microbially reduced iron(iii) oxi ...200111329715
piezoresponse of the cyo-operon coding for quinol oxidase subunits in a deep-sea piezophilic bacterium, shewanella violacea.we have isolated the genes for quinol oxidase from a deep-sea piezophilic bacterium, shewanella violacea. analysis of the deduced amino acid sequences of the cyo subunits showed that this oxidase has high similarity to escherichia coli bo-type quinol oxidase. northern blot analysis showed that these genes are expressed at a high level when the bacterium is grown at elevated pressure. upstream in the cyo-operon, a sigma54-binding motif and an octamer sequence unit were found, suggesting that thes ...200111330692
cell surface electrochemical heterogeneity of the fe(iii)-reducing bacteria shewanella putrefaciens.acid-base titration experiments and electrostatic force microscopy (efm) were used to investigate the cell surface electrochemical heterogeneity of the fe(iii)-reducing bacteria, shewanella putrefaciens. the acid-base titrations extended from ph 4 to 10, and the titration data were fit using a linear programming pka spectrum approach. overall, a five-site model accounted for the observed titration behavior with the most acidic sites corresponding to carboxylic groups and phosphodiester groups, i ...200111347607
microbial reduction of fe(iii) and sorption/precipitation of fe(ii) on shewanella putrefaciens strain cn32.the influence of fe(ii) on the dissimilatory bacterial reduction of an fe(iii) aqueous complex (fe(iii)-citrate(aq)) was investigated using shewanella putrefaciens strain cn32. the sorption of fe(ii) on cn32 followed a langmuir isotherm. least-squares fitting gave a maximum sorption capacity of qmax = 4.19 x 10(-3) mol/10(12) cells (1.19 mmol/m2 of cell surface area) and an affinity coefficient of log k = 3.29. the growth yield of cn32 with respect to fe(iii)aq reduction showed a linear trend wi ...200111348071
biotransformation of ni-substituted hydrous ferric oxide by an fe(iii)-reducing bacterium.the reductive biotransformation of a ni(2+)-substituted (5 mol %) hydrous ferric oxide (nihfo) by shewanella putrefaciens, strain cn32, was investigated under anoxic conditions at circumneutral ph. our objectives were to define the influence of ni2+ substitution on the bioreducibility of the hfo and the biomineralization products formed and to identify biogeochemical factors controlling the phase distribution of ni2+ during bioreduction. incubations with cn32 and nihfo were sampled after 14 and ...200111349281
microbiology. how bacteria respire minerals. 200111360987
characterization of facultative oligotrophic bacteria from polar seas by analysis of their fatty acids and 16s rdna sequences.one hundred and seventy three bacterial strains, isolated previously after enrichment under oligotrophic, psychrophylic conditions from arctic (98 strains) and antarctic seawater (75 strains), were characterized by gas-liquid chromatographic analysis of their fatty acid compositions. by numerical analysis, 8 clusters, containing 2 to 59 strains, could be delineated, and 8 strains formed separate branches. five clusters contained strains from both poles, two minor clusters were confined to arctic ...200111403404
shewanella japonica sp. nov.two strains of agar-digesting bacteria, kmm 3299t and kmm 3300, respectively isolated from sea water and the mussel protothaca jedoensis, have been characterized. based on sequencing of the 16s rrna gene, kmm 3299t showed the highest similarity (93-95%) to members of the genus shewanella. the g+c contents of the dnas of these strains were 43-44 mol%. the level of dna homology between the two strains was conspecific (95%), indicating that they represent a distinct genospecies. these organisms wer ...200111411670
iron promoted reduction of chromate by dissimilatory iron-reducing bacteria.chromate is a priority pollutant within the u.s. and many other countries, the hazard of which can be mitigated by reduction to the trivalent form of chromium. here we elucidate the reduction of cr(vi) to cr(iii) via a closely coupled, biotic-abiotic reductive pathway under iron-reducing conditions. injection of chromate into stirred-flow reactors containing shewanella alga strain bry and iron (hydr)oxides of varying stabilities results in complete reduction to cr(iii). the maximum sustainable c ...200111351723
characterisation of volatile compounds produced by bacteria isolated from the spoilage flora of cold-smoked salmon.this study investigated the volatile compounds produced by bacteria belonging to nine different bacterial groups: lactobacillus sake, l. farciminis, l. alimentarius, carnobacterium piscicola, aeromonas sp., shewanella putrefaciens, brochothrix thermosphacta, photobacterium phosphoreum and enterobacteriaceae isolated from cold-smoked salmon. each bacterial group was represented by several strains. in addition, combinations of the groups were examined as well. sterile blocks of cold-smoked salmon ...200111428576
uncertainties of monod kinetic parameters nonlinearly estimated from batch experiments.monod kinetic parameters (ks, micromax, and y) that are estimated from batch experimental data can have large uncertainties due to linear correlations between them. the degree of correlation and the resulting uncertainties of the monod parameters are functions of the initial experimental conditions, the values of the parameters, the type and magnitude of measurement errors, and the sampling number. careful manipulation of experimental conditions can reduce the correlations between monod paramete ...200111351998
production of polyunsaturated fatty acids by polyketide synthases in both prokaryotes and eukaryotes.polyunsaturated fatty acids (pufas) are essential membrane components in higher eukaryotes and are the precursors of many lipid-derived signaling molecules. here, pathways for pufa synthesis are described that do not require desaturation and elongation of saturated fatty acids. these pathways are catalyzed by polyketide synthases (pkss) that are distinct from previously recognized pkss in both structure and mechanism. generation of cis double bonds probably involves position-specific isomerases; ...200111452122
characterization of alanine and malate dehydrogenases from a marine psychrophile strain pa-43.alanine dehydrogenase (aladh: ec 1.4.1.1), malate dehydrogenase (mdh: ec 1.1.1.37), and glutamate dehydrogenase (ec 1.4.1.2), all nad+ dependent, were detected in extracts from a psychrophilic bacterium, strain pa-43, isolated from a sea urchin off the icelandic coast. characterization tests suggested that the strain had a close relationship to vibrio, but sequencing of part of the 16s rdna gene placed the bacterium among shewanella species in a constructed phylogenetic tree. the bacterium had a ...200111453464
isolation and characterization of a shewanella putrefaciens mr-1 electron transport regulator etra mutant: reassessment of the role of etra.shewanella putrefaciens mr-1 has emerged as a good model to study anaerobic respiration and electron transport-linked metal reduction. its remarkable respiratory plasticity suggests the potential for a complex regulatory system to coordinate electron acceptor use in the absence of o(2). it had previously been suggested that etra (electron transport regulator a), an analog of fnr (fumarate nitrate regulator) from escherichia coli, may regulate gene expression for anaerobic electron transport. an ...200111466298
purification and characterisation of a serine peptidase from the marine psychrophile strain pa-43.an extracellular serine peptidase, purified from the culture supernatant of the sub-arctic psychrophilic bacterium strain pa-43, is monomeric, with a relative molecular mass of 76000, and an unusually low pi of 3.8. the peptidase is active towards n-succinyl aapf p-nitroanilide and n-succinyl aapl p-nitroanilide, indicating a chymotrypsin-like substrate specificity. it is inhibited by the serine peptidase inactivator phenylmethylsulfonyl fluoride, but not by edta or egta, suggesting that added m ...200111470375
bacterial recognition of mineral surfaces: nanoscale interactions between shewanella and alpha-feooh.force microscopy has been used to quantitatively measure the infinitesimal forces that characterize interactions between shewanella oneidensis (a dissimilatory metal-reducing bacterium) and goethite (alpha-feooh), both commonly found in earth near-surface environments. force measurements with subnanonewton resolution were made in real time with living cells under aerobic and anaerobic solutions as a function of the distance, in nanometers, between a cell and the mineral surface. energy values [i ...200111359008
kinetic analysis of the bacterial reduction of goethite.the kinetics of dissimilatory reduction of goethite (alpha-feooh) was studied in batch cultures of a groundwater bacterium, shewanella putrefaciens, strain cn32 in ph 7 bicarbonate buffer. the rate and extent of goethite reduction were measured as a function of electron acceptor (goethite) and donor (lactate) concentrations. increasing goethite concentrations increased both the rate and extent of fe(iii) reduction when cell and lactate concentrations were held constant. however, constant initial ...200111432552
identification of a small tetraheme cytochrome c and a flavocytochrome c as two of the principal soluble cytochromes c in shewanella oneidensis strain mr1.two abundant, low-redox-potential cytochromes c were purified from the facultative anaerobe shewanella oneidensis strain mr1 grown anaerobically with fumarate. the small cytochrome was completely sequenced, and the genes coding for both proteins were cloned and sequenced. the small cytochrome c contains 91 residues and four heme binding sites. it is most similar to the cytochromes c from shewanella frigidimarina (formerly shewanella putrefaciens) ncimb400 and the unclassified bacterial strain h1 ...200111425747
dna/dna hybridization to microarrays reveals gene-specific differences between closely related microbial genomes.dna microarrays constructed with full length orfs from shewanella oneidensis, mr-1, were hybridized with genomic dna from nine other shewanella species and escherichia coli k-12. this approach enabled visualization of relationships between organisms by comparing individual orf hybridizations to 164 genes and is further amenable to high-density high-throughput analyses of complete microbial genomes. conserved genes (arca and atp synthase) were identified among all species investigated. the mtr op ...200111493693
isolation and characterization of psychotrophic bacteria from oil-reservoir water and oil sands.four psychrotrophic strains, which grew at 4 degrees c but not at 37 degrees c, were isolated from japanese oil-reservoir water (strains sib1, sic1, sis1) and canadian oil sands (strain cab1). strains sib1, sis1, and cab1 had a maximum growth rate at 20 degrees c and grew to the highest cell densities at the cultivation temperature of 0-4 degrees c. strain sis1 was capable of growing even at -5 degrees c. the growth profile of strain sic1 was rather similar to that of a mesophilic bacterium. str ...200111525631
growth of the facultative anaerobe shewanella putrefaciens by elemental sulfur reduction.the growth of bacteria by dissimilatory elemental sulfur reduction is generally associated with obligate anaerobes and thermophiles in particular. here we describe the sulfur-dependent growth of the facultatively anaerobic mesophile shewanella putrefaciens. six of nine representative s. putrefaciens isolates from a variety of environments proved able to grow by sulfur reduction, and strain mr-1 was chosen for further study. growth was monitored in a minimal medium (usually with 0.05% casamino ac ...199611536738
physiology and enzymology involved in denitrification by shewanella putrefaciens.nitrate reduction to n2o was investigated in batch cultures of shewanella putrefaciens mr-1, mr-4, and mr-7. all three strains reduced nitrate to nitrite to n2o, and this reduction was coupled to growth, whereas ammonium accumulation was very low (0 to 1 micromol liter-1). all s. putrefaciens isolates were also capable of reducing nitrate aerobically; under anaerobic conditions, nitrite levels were three- to sixfold higher than those found under oxic conditions. nitrate reductase activities (31 ...199711536813
endogenous isolation of replicon probes for assessing plasmid ecology of marine sediment microbial communities.six functional replication origins (repga14, repga33, repga70, repsd41, repsd164 and repsd172), obtained from endogenously isolated, broad-host-range (bhr) marine plasmids ranging in size from 5 to 60 kb, were used to determine plasmid occurrence in three coastal marine sediment sites (in california, georgia and south carolina, usa). the plasmid-specific replicons were isolated from plasmid-bearing marine sediment bacteria belonging to the alpha and gamma subclasses of the proteobacteria. the pl ...200111495987
influence of acetate and co2 on the tmao-reduction reaction by shewanella baltica.in this work, the tmao-reduction by shewanella baltica, one of the representative spoilage organisms in modified atmosphere packaged marine fish fillets, and the effect of acetate and co2 on this reduction were studied in vitro. the growth of s. baltica and the corresponding evolution of some compounds (acetate, lactate, pyruvate, glucose and trimethylamine (tma)) were followed during storage at 4 degrees c in two types of broths. the first medium was a defined medium (ph = 6.8) to which lactate ...200111545211
dissolution and reduction of magnetite by bacteria.magnetite (fe3o4) is an iron oxide of mixed oxidation state [fe(ii), fe(iii)] that contributes largely to geomagnetism and plays a significant role in diagenesis in marine and freshwater sediments. magnetic data are the primary evidence for ocean floor spreading and accurate interpretation of the sedimentary magnetic record depends on an understanding of the conditions under which magnetite is stable. though chemical reduction of magnetite by dissolved sulfide is well known, biological reduction ...199511539843
structure and properties of novel inclusions in shewanella putrefaciens.cytoplasmic inclusions surrounded by a bilayer membrane were seen in thin sections. negatively stained and freeze-fractured preparations of shewanella putrefaciens. cells harvested from the late exponential and early stationary phase showed a higher number of these vesicles than bacteria isolated from early exponential or late stationary phase. chemical dyes for polyphosphate or poly-beta-hydroxybutyrate did not stain the material enclosed within these vesicles. elemental analysis of the materia ...199611536730
effect of sampling method on the representative recovery of microorganisms from the surfaces of aquacultured finfish.the objective of this study was to determine if a gentle rinse procedure was equivalent to the combination of excision and homogenization with a stomacher for the relative removal of various microorganisms from finfish fillets. fillets of hybrid striped bass and rainbow trout were obtained from local markets and sampled using three methods: rinse (r), excision followed by homogenization in a stomacher (s), and homogenization of fillets following a rinse (rs). microorganisms were enumerated on se ...200111601699
anaerobic electron acceptor chemotaxis in shewanella putrefaciens.shewanella putrefaciens mr-1 can grow either aerobically or anaerobically at the expense of many different electron acceptors and is often found in abundance at redox interfaces in nature. such redox interfaces are often characterized by very strong gradients of electron acceptors resulting from rapid microbial metabolism. the coincidence of s. putrefaciens abundance with environmental gradients prompted an examination of the ability of mr-1 to sense and respond to electron acceptor gradients ...199511536689
kinetic and crystallographic analysis of the key active site acid/base arginine in a soluble fumarate reductase.there is now overwhelming evidence supporting a common mechanism for fumarate reduction in the respiratory fumarate reductases. the x-ray structures of substrate-bound forms of these enzymes indicate that the substrate is well positioned to accept a hydride from fad and a proton from an arginine side chain. recent work on the enzyme from shewanella frigidimarina [doherty, m. k., pealing, s. l., miles, c. s., moysey, r., taylor, p., walkinshaw, m. d., reid, g. a., and chapman, s. k. (2000) bioche ...200111591148
performance of pseudomonas cfc-selective medium in the fish storage ecosystems.pseudomonas agar base supplemented with cephaloridine, fucidin, and cetrimide (cfc) was used to count pseudomonas populations on fish. both enterobacteriaceae and shewanella putrefaciens were able to grow on the cfc medium. evaluation of the performance of cfc-selective for pseudomonads medium, on fish samples stored aerobically and under a modified atmosphere at 0, 10 and 20 degrees c was tested. the selectivity of the medium was affected by storage temperatures and the type of packaging of the ...200111576688
rupture of a primary aortic aneurysm infected with shewanella alga.bacteria of the genus shewanella are rarely implicated in bacteremia. we report a case of rupture of a primary aneurysm infected with shewanella alga.200111728048
dissimilatory fe(iii) and mn(iv) reduction by shewanella putrefaciens requires fere, a homolog of the pule (gspe) type ii protein secretion gene.shewanella putrefaciens strain 200 respires anaerobically on a wide range of compounds as the sole terminal electron acceptor, including ferric iron [fe(iii)] and manganese oxide [mn(iv)]. previous studies demonstrated that a 23.3-kb s. putrefaciens wild-type dna fragment conferred metal reduction capability to a set of respiratory mutants with impaired fe(iii) and mn(iv) reduction activities (t. dichristina and e. delong, j. bacteriol. 176:1468-1474, 1994). in the present study, the smallest co ...200211741854
the antibacterial activity of triclosan-impregnated storage boxes against staphylococcus aureus, escherichia coli, pseudomonas aeruginosa, bacillus cereus and shewanella putrefaciens in conditions simulating domestic use.antimicrobial resistance has increased over the past decade causing concern for public health. domestic antimicrobial products containing triclosan (2,4,4'-trichloro-2'-hydroxydiphenylether), a broad-spectrum antibacterial agent, were introduced in 1997 and have become popular among consumers. cross-resistance to other antibacterial agents has been suggested as a possible consequence of their widespread use. triclosan-impregnated plastic storage boxes were tested for activity against staphylococ ...200211751771
sorption of fe (hydr)oxides to the surface of shewanella putrefaciens: cell-bound fine-grained minerals are not always formed de novo.shewanella putrefaciens, a gram-negative, facultative anaerobe, is active in the cycling of iron through its interaction with fe (hydr)oxides in natural environments. fine-grained fe precipitates that are attached to the outer membranes of many gram-negative bacteria have most often been attributed to precipitation and growth of the mineral at the cell surface. our study of the sorption of nonbiogenic fe (hydr)oxides revealed, however, that large quantities of nanometer-scale ferrihydrite (hydro ...200111722905
chemical characterization of lipid a from some marine proteobacteria.lipids a from type and wild strains of marine proteobacteria belonging to alteromonadaceae (alteromonas (1 species), idiomarina (1 species), and pseudoalteromonas (8 species) genera) and vibrionaceae (shewanella (1 species) and vibrio (1 species) genera) families and marinomonas genus (1 species) were isolated by hydrolysis of their respective lipopolysaccharides with 1% acetic acid. based on thin-layer chromatography data, the lipids a studied had low heterogeneity and generated family-specific ...200111703190
kinetics of chromium (vi) reduction by a type strain shewanella alga under different growth conditions.we conducted kinetic batch experiments to determine the reduction of chromium(vi) by a type strain of shewanella alga (bry-mt) atcc 55627. chromium(vi) was reduced to chromium(iii) by bry-mt grown in three different substrates: bhib (brain heart infusion broth), tsb (tryptic soy broth), and m9 (minimum broth). four different cr(vi) concentrations 4.836, 10.00, 37.125, and 260.00 mg l-1 were reduced at different rates by bry-mt in both aerobic and anaerobic conditions. bry-mt grown in bhib reduce ...200111706794
intracellular iron minerals in a dissimilatory iron-reducing bacterium.among prokaryotes, there are few examples of controlled mineral formation; the formation of crystalline iron oxides and sulfides [magnetite (fe3o4) or greigite (fe3s4)] by magnetotactic bacteria is an exception. shewanella putrefaciens cn32, a gram-negative, facultative anaerobic bacterium that is capable of dissimilatory iron reduction, produced microscopic intracellular grains of iron oxide minerals during growth on two-line ferrihydrite in a hydrogen-argon atmosphere. the minerals, formed at ...200211778045
iron(ii,iii) hydroxycarbonate green rust formation and stabilization from lepidocrocite bioreduction.bioreduction of the well-crystallized ferric oxyhydroxide gamma-feooh lepidocrocite was investigated in batch cultures using shewanella putrefaciens bacterium (strain cip 8040) at initial ph 7.5 in bicarbonate buffer. the cultures were performed with formate as electron donor without phosphate, in the presence or absence of anthraquinone-2,6-disulfonate (aqds) as electron shuttle. during lepidocrocite reduction, the iron(ii,iii) hydroxycarbonate green rust gr(co32-) was characterized by x-ray di ...200211811482
transcriptional and proteomic analysis of a ferric uptake regulator (fur) mutant of shewanella oneidensis: possible involvement of fur in energy metabolism, transcriptional regulation, and oxidative stress.the iron-directed, coordinate regulation of genes depends on the fur (ferric uptake regulator) gene product, which acts as an iron-responsive, transcriptional repressor protein. to investigate the biological function of a fur homolog in the dissimilatory metal-reducing bacterium shewanella oneidensis mr-1, a fur knockout strain (fur1) was generated by suicide plasmid integration into this gene and characterized using phenotype assays, dna microarrays containing 691 arrayed genes, and two-dimensi ...200211823232
measurement of iron(iii) bioavailability in pure iron oxide minerals and soils using anthraquinone-2,6-disulfonate oxidation.the quinol form (ahds) of 9,10-anthraquinone-2,6-disulfonate (aqds) was used as a titrant to determine bioavailability of fe(iii) in pure iron minerals and several soils. ahds oxidation to aqds was coupled to fe(iii) reduction to fe(ll) in biological media consisting of trace salts and vitamins, providing estimates of bioavailability consistentwith the biogeochemical mechanisms and conditions that control fe(iii) availability to iron-reducing bacteria. iron(iii) oxide sources were synthetic oxid ...200111775166
role of menaquinones in fe(iii) reduction by membrane fractions of shewanella putrefaciens.two tn5-generated mutants of shewanella putrefaciens with insertions in mend and menb were isolated and analyzed. both mutants were deficient in the use of several terminal electron acceptors, including fe(iii). this deficiency was overcome by the addition of menaquinone (vitamin k(2)). isolated membrane fractions from both mutants were unable to reduce fe(iii) in the absence of added menaquinone when formate was used as the electron donor. these results indicate that menaquinones are essential ...200211790756
heat labile ribonuclease hi from a psychrotrophic bacterium: gene cloning, characterization and site-directed mutagenesis.the rnha gene encoding rnase hi from a psychrotrophic bacterium, shewanella sp. sib1, was cloned, sequenced and overexpressed in an rnh mutant strain of escherichia coli. sib1 rnase hi is composed of 157 amino acid residues and shows 63% amino acid sequence identity to e.coli rnase hi. upon induction, the recombinant protein accumulated in the cells in an insoluble form. this protein was solubilized and purified in the presence of 7 m urea and refolded by removing urea. determination of the enzy ...200111809928
molecular cloning and characterization of sphingolipid ceramide n-deacylase from a marine bacterium, shewanella alga g8.recently, lyso-sphingolipids have been identified as ligands for several orphan g protein-coupled receptors, although the molecular mechanism for their generation has yet to be clarified. here, we report the molecular cloning of the enzyme, which catalyzes the generation of lyso-sphingolipids from various sphingolipids (sphingolipid ceramide n-deacylase). the 75-kda enzyme was purified from the marine bacterium, shewanella alga g8, and its gene was cloned from a g8 genomic library using sequence ...200211827965
shewanella frigidimarina and shewanella livingstonensis sp. nov. isolated from antarctic coastal areas.three strains of psychrophilic bacteria isolated from antarctic coastal marine environments were studied to determine their taxonomic position. these bacteria were gram-negative rods, facultatively anaerobic and motile by means of a single polar flagellum. none of the bacterial isolates had an na+ requirement. only one of the strains was capable of producing h2s from thiosulfate. the dna base content of these bacteria was 41-42 mol % g+c. dna-dna hybridization experiments showed that the isolate ...200211837303
ear infections with shewanella alga: a bacteriologic, clinical and epidemiologic study of 67 cases.objective: to present bacteriologic and clinical data on 67 patients from the island of funen, denmark, with shewanella alga, a bacterium rarely seen in scandinavia, isolated from ear swabs. included in the study is an examination of the occurrence of s. alga in sea water around the island. methods: bacteriologic examination and antibiotic susceptibility testing of 67 clinical isolates, 11 sea-water isolates and two reference strains were conducted. clinical information was obtained from the ref ...199711864129
microbial activity at gigapascal pressures.we observed physiological and metabolic activity of shewanella oneidensis strain mr1 and escherichia coli strain mg1655 at pressures of 68 to 1680 megapascals (mpa) in diamond anvil cells. we measured biological formate oxidation at high pressures (68 to 1060 mpa). at pressures of 1200 to 1600 mpa, living bacteria resided in fluid inclusions in ice-vi crystals and continued to be viable upon subsequent release to ambient pressures (0.1 mpa). evidence of microbial viability and activity at these ...200211859192
microbial iron respiration can protect steel from corrosion.microbiologically influenced corrosion (mc) of steel has been attributed to the activity of biofilms that include anaerobic microorganisms such as iron-respiring bacteria, yet the mechanisms by which these organisms influence corrosion have been unclear. to study this process, we generated mutants of the iron-respiring bacterium shewanella oneidensis strain mr-1 that were defective in biofilm formation and/or iron reduction. electrochemical impedance spectroscopy was used to determine changes in ...200211872499
protective role of tolc in efflux of the electron shuttle anthraquinone-2,6-disulfonate.extracellular electron transfer can play an important role in microbial respiration on insoluble minerals. the humic acid analog anthraquinone-2,6-disulfonate (aqds) is commonly used as an electron shuttle during studies of extracellular electron transfer. here we provide genetic evidence that aqds enters shewanella oneidensis strain mr-1 and causes cell death if it accumulates past a critical concentration. a tolc homolog protects the cell from toxicity by mediating the efflux of aqds. electron ...200211872737
the inti-like tyrosine recombinase of shewanella oneidensis is active as an integron integrase.we have found an integron-like integrase gene and an atti site in shewanella oneidensis as part of a small chromosomal integron. we have cloned this gene and tested the ability of the integrase to excise cassettes from various integrons. most cassettes flanked by two attc sites are readily excised, while cassettes in the "first" position, with an atti1 or atti3 site on one end, are not excised. an exception is a cassette with atti2 on one end. the atti2 site, from tn7, has greater similarity to ...200211872738
reconstitution of the trimethylamine oxide reductase regulatory elements of shewanella oneidensis in escherichia coli.several bacteria can grow by using small organic compounds such as trimethylamine oxide (tmao) as electron acceptors. in shewanella species, the tmao reductase respiratory system is encoded by the torecad operon. we showed that production of the tmao reductase of s. oneidensis was induced by tmao and repressed by oxygen, and we noticed that a three-gene cluster (torstr) encoding a complex two-component regulatory system was present downstream of the torecad operon. we introduced the torstr gene ...200211844754
a novel species of alkaliphilic bacillus that produces an oxidatively stable alkaline serine protease.a novel gram-positive, strictly aerobic, motile, sporulating, and facultatively alkaliphilic bacterium designated ksm-kp43 was isolated from a sample of soil. the results of 16s rrna sequence analysis placed this bacterium in a cluster with bacillus halmapalus. however, the level of the dna-dna hybridization of ksm-kp43 with b. halmapalus was less than 25%. moreover, the g + c contents of the genomic dna were 41.6 mol% for ksm-kp43 and 38.6 mol% for b. halmapalus. because there were also differe ...200211878564
microbiology. weight of the world on microbes' shoulders. 200211859165
control of natural microbial flora and listeria monocytogenes in vacuum-packaged trout at 4 and 10 degrees c using irradiation.the effect of gamma irradiation on the natural microflora of whole salted vacuum-packaged trout at 4 and 10 degrees c was studied. in addition, the effectiveness of gamma irradiation in controlling listeria monocytogenes inoculated into trout was investigated. irradiation at doses of 0.5 and 2 kgy affected populations of bacteria, namely, pseudomonas spp., brochothrix thermosfacta, lactic acid bacteria, h2s-producing bacteria typical of shewanella putrefaciens, and enterobacteriaceae, at both 4 ...200211899050
microbial diversity of cultivatable bacteria associated with the north sea bryozoan flustra foliacea.the microbial diversity of cultivatable bacteria associated with the bryozoan species flustra foliacea from the north sea was investigated by a molecular approach. amplified ribosomal rna restriction analyses (ardra) and 16s rdna partial sequence analysis revealed differences in the composition of cultivatable bacteria populations from single bryozoan colonies collected from two different sampling sites in the north sea as well from one site taken at different points in time. whereas gamma-prote ...200111876370
gene and protein expression profiles of shewanella oneidensis during anaerobic growth with different electron acceptors.changes in mrna and protein expression profiles of shewanella oneidenesis mr-1 during switch from aerobic to fumarate-, fe(iii)-, or nitrate-reducing conditions were examined using dna microarrays and two-dimensional polyacrylamide gel electrophoresis (2-d page). in response to changes in growth conditions, 121 of the 691 arrayed genes displayed at least a two-fold difference in transcript abundance as determined by microarray analysis. genes involved in aerobic respiration encoding cytochrome c ...200211881834
solution structure of a monoheme ferrocytochrome c from shewanella putrefaciens and structural analysis of sequence-similar proteins: functional implications.within the frame of the characterization of the structure and function of cytochromes c, an 81-amino acid cytochrome c was identified in the genome of shewanella putrefaciens. because of the scarce information about bacterial cytochromes of this type and the large variability in sequences and possibly function, we decided to proceed to its structural characterization. this protein was expressed in escherichia coli and purified. the oxidized species is largely high spin, with a detached methionin ...200211955059
effects of fe(iii) chemical speciation on dissimilatory fe(iii) reduction by shewanella putrefaciens.shewanella putrefaciens, a heterotrophic member of the gamma-proteobacteria is capable of respiring anaerobically on fe(iii) as the sole terminal electron acceptor (tea). recent genetic and biochemical studies have indicated that anaerobic fe(iii) respiration by s. putrefaciens requires outer-membrane targeted secretion of respiration-linked fe(iii) reductases. thus, the availability of fe(iii) to s. putrefaciens may be governed by equilibrium chemical speciation both in the solution phase and a ...200211871551
comparison of adhesion of the food spoilage bacterium shewanella putrefaciens to stainless steel and silver surfaces.to compare the number of attached shewanella putrefaciens on stainless steel with different silver surfaces, thus evaluating whether silver surfaces could contribute to a higher hygienic status in the food industry.200211972695
sensory, chemical and bacteriological changes during storage of iced squid (todaropsis eblanae).to relate sensory shelf-life of iced whole and gutted squid to bacterial growth and chemical changes.200211972700
electron energy loss spectroscopy techniques for the study of microbial chromium(vi) reduction.electron energy loss spectroscopy (eels) techniques were used to determine oxidation state, at high spatial resolution, of chromium associated with the metal-reducing bacteria, shewanella oneidensis, in anaerobic cultures containing cr(vi)o4(2-). these techniques were applied to fixed cells examined in thin section by conventional transmission electron microscopy (tem) as well as unfixed, hydrated bacteria examined by environmental cell (ec)-tem. two distinct populations of bacteria were observe ...200211943357
geobacter metallireducens accesses insoluble fe(iii) oxide by chemotaxis.microorganisms that use insoluble fe(iii) oxide as an electron acceptor can have an important function in the carbon and nutrient cycles of aquatic sediments and in the bioremediation of organic and metal contaminants in groundwater. although fe(iii) oxides are often abundant, fe(iii)-reducing microbes are faced with the problem of how to access effectively an electron acceptor that can not diffuse to the cell. fe(iii)-reducing microorganisms in the genus shewanella have resolved this problem by ...200211961561
chromate reduction in shewanella oneidensis mr-1 is an inducible process associated with anaerobic growth.cr(vi) reduction was observed during tests with shewanella oneidensis mr-1 (previously named s. putrefaciens mr-1) while being grown with nitrate or fumarate as electron acceptor and lactate as electron donor. from the onset of anoxic growth on fumarate, we measured a gradual and progressive increase in the specific cr(vi) reduction rate with incubation time until a maximum was reached at late exponential/early stationary phase. under denitrifying conditions, the specific cr(vi) reduction rate w ...200211934298
melanin production and use as a soluble electron shuttle for fe(iii) oxide reduction and as a terminal electron acceptor by shewanella algae bry.dissimilatory metal-reducing bacteria (dmrb) utilize numerous compounds as terminal electron acceptors, including insoluble iron oxides. the mechanism(s) of insoluble-mineral reduction by dmrb is not well understood. here we report that extracellular melanin is produced by shewanella algae bry. the extracted melanin served as the sole terminal electron acceptor. upon reduction the reduced, soluble melanin reduced insoluble hydrous ferric oxide in the absence of bacteria, thus demonstrating that ...200211976119
improved detection of polyunsaturated fatty acids as phenacyl esters using liquid chromatography-ion trap mass spectrometry.the fatty acid composition of shewanella pealeana was determined by the analysis of fatty acid methyl esters via gas chromatography-mass spectrometry (gc-ms) and fatty acid 2-oxo-phenylethyl esters via high-performance liquid chromatography-mass spectrometry (lc-ms) combined with ultra violet (uv) detection. there was good agreement between the percentage composition of components determined by gc-ms and lc-uv analyses. however, lc-ms analysis using atmospheric pressure chemical ionization (apci ...200211997161
modeling the inhibition of the bacteral reduction of u(vi) by beta-mno2(s).pyrolusite (beta-mno2(s)) was used to assess the influence of a competitive electron acceptor on the kinetics of reduction of aqueous uranyl carbonate by a dissimilatory metal-reducing bacterium (dmrb), shewanella putrefaciens strain cn32. the enzymatic reduction of u(vi) and beta-mno2(s) and the abiotic redox reaction between beta-mno2(s) and biogenic uraninite (uo2(s)) were independently investigated to allow for interpretation of studies of u(vi) bioreduction in the presence of beta-mno2(s). ...200211999050
chromate/nitrite interactions in shewanella oneidensis mr-1: evidence for multiple hexavalent chromium [cr(vi)] reduction mechanisms dependent on physiological growth conditions.inhibition of hexavalent chromium [cr(vi)] reduction due to nitrate and nitrite was observed during tests with shewanella oneidensis mr-1 (previously named shewanella putrefaciens mr-1 and henceforth referred to as mr-1). initial cr(vi) reduction rates were measured at various nitrite concentrations, and a mixed inhibition kinetic model was used to determine the kinetic parameters-maximum cr(vi) reduction rate and inhibition constant [v(max,cr(vi)) and k(i,cr(vi))]. values of v(max,cr(vi)) and k ...200212001169
phylogeny and abundance of novel denitrifying bacteria isolated from the water column of the central baltic sea.the baltic sea is an estuarine ecosystem where denitrification in the low oxic and anoxic parts of the deep water contributes significantly to the nitrogen budget. seventy-six heterotrophic, denitrifying, strains have been isolated by four cultivation procedures from the water column of the gotland deep, the main anoxic basin of the central baltic. phylogenetic positions of representative strains of 10 different genotypes, grouped beforehand by low molecular weight (lmw) rna profiling, were esti ...200112024255
geobiologists: as diverse as the bugs they study. 200212004114
electron-transfer mechanisms through biological redox chains in multicenter enzymes.a new approach for studying intramolecular electron transfer in multicenter enzymes is described. two fumarate reductases, adsorbed on an electrode in a fully active state, have been studied using square-wave voltammetry as a kinetic method to probe the mechanism of the long-range electron transfer to and from the buried active site. flavocytochrome c(3) (fcc(3)), the globular fumarate reductase from shewanella frigidimarina, and the soluble subcomplex of the membrane-bound fumarate reductase of ...200212010043
transcriptional regulation under pressure conditions by rna polymerase sigma54 factor with a two-component regulatory system in shewanella violacea.deep-sea bacteria have unique systems for gene and protein expression controlled by hydrostatic pressure. one of the sigma factors, sigma54, was found to play an important role in pressure-regulated transcription in a deep-sea piezophilic bacterium, shewanella violacea. a glutamine synthetase gene (glna) has been targeted as a model for the pressure-regulated promoter to investigate transcriptional regulation by the sigma54 factor. recognition sites for sigma54 and sigma70 factors were observed ...200212013439
[antagonistic interactions between stress factors during the growth of microorganisms under conditions simulating the parameters of their natural ecotopes].two stress factors, hypoxia (microaerobic conditions) and a high salt concentration, if applied simultaneously to aerobic microorganisms, display an antagonistic mode of interaction. as a result, the nacl level that is usually optimal for moderate halophiles (5-6%) becomes optimal for the growth of weak halophiles (rhodococcus erythropolis and shewanella sp. cn32); the halotolerant yeast yarrowia lypolytica acquires halophilic properties (with a growth optimum at a nacl concentration of 10%), an ...200212024812
genetic complementation of an outer membrane cytochrome omcb mutant of shewanella putrefaciens mr-1 requires omcb plus downstream dna.anaerobically grown cells of the metal-reducing bacterium shewanella putrefaciens mr-1 contain multiple outer membrane (om) cytochromes. a gene replacement mutant (strain omcb1) lacking the om cytochrome omcb is markedly deficient in the reduction of mno2 and exhibits reduced rates of fe(iii) reduction. the levels of other om cytochromes are also decreased in omcb1. complementation of omcb1 with wild-type omcb did not restore any of these defects. however, a 21-kb genomic fragment from mr-1, whi ...200212039733
structure of the phenol-soluble polysaccharide from shewanella putrefaciens strain a6.the structure of the phenol-soluble polysaccharide from shewanella putrefaciens strain a6 has been elucidated. chemical modifications of the polymer in conjunction with 1h and 13c nmr spectroscopy, including 2d techniques, were employed in the analysis. it is concluded that the repeating unit is composed of two nine-carbon sugars as follows: -->4)-alpha-nonpa-(2-->3)-beta-sugp-(1--> where alpha-nonpa is 5-acetamido-7-acetamidino-8-o-acetyl-3,5,7,9-tetradeoxy-l-glycero-alpha-d-galacto-non-2-uloso ...200212062527
cloning of cold-active alkaline phosphatase gene of a psychrophile, shewanella sp., and expression of the recombinant enzyme.a psychrophilic alkaline phosphatase (ec 3.1.3.1) from shewanella sp. is a cold-active enzyme that has high catalytic activity at low temperature [ishida et al. (1998) biosci. biotechnol. biochem., 62, 2246-2250]. here, we identified the nucleotide sequence of a gene encoding the enzyme after cloning with the polymerase chain reaction (pcr) and inverted pcr techniques. the deduced amino acid sequence of the enzyme contained conserved amino acids found among mesophilic alkaline phosphatases and s ...200212036047
phylogenetic diversity of numerically important arctic sea-ice bacteria cultured at subzero temperature.heterotrophic bacteria in sea ice play a key role in carbon cycling, but little is known about the predominant players at the phylogenetic level. in a study of both algal bands and clear ice habitats within summertime arctic pack ice from the chukchi sea, we determined the abundance of total bacteria and actively respiring cells in melted ice samples using epifluorescence microscopy and the stains 4', 6'-diamidino-2-phenylindole 2hcl (dapi) and 5-cyano-2,3-ditolyl tetrazolium chloride (ctc), res ...200212037610
degradation of tce, cr(vi), sulfate, and nitrate mixtures by granular iron in flow-through columns under different microbial conditions.flow-through aquifer columns packed with a middle layer of granular iron (fe0) were used to study the applicability and limitations of bio-enhanced fe0 barriers for the treatment of contaminant mixtures in groundwater. concentration profiles along the columns showed extensive degradation of hexavalent chromium cr(vi), nitrate, sulfate, and trichloroethene (tce), mainly in the fe0 layer. one column was bioaugmented with shevanella algae bry, an iron-reducing bacterium that could enhance fe0 react ...200212092572
role of his505 in the soluble fumarate reductase from shewanella frigidimarina.the x-ray structure of the soluble fumarate reductase from shewanella frigidimarina [taylor, p., pealing, s. l., reid, g. a., chapman, s. k., and walkinshaw, m. d. (1999) nat. struct. biol. 6, 1108-1112] clearly shows the presence of an internally bound sodium ion. this sodium ion is coordinated by one solvent water molecule (wat912) and five backbone carbonyl oxygens from thr506, met507, gly508, glu534, and thr536 in what is best described as octahedral geometry (despite the rather long distanc ...200212093271
enhancement of biological reduction of hematite by electron shuttling and fe(ii) complexation.natural organic matter (nom) enhancement of the biological reduction of hematite (alpha-fe2o3) by the dissimilatory iron-reducing bacterium shewanella putrefaciens strain cn32 was investigated under nongrowth conditions designed to minimize precipitation of biogenic fe(ii). hydrogen served as the electron donor. anthraquinone-2,6-disulfonate (aqds), methyl viologen, and methylene blue [quinones with an ew0 (ph 7) of 0.011 v or less], ferrozine [a strong fe(ii) complexing agent], and characterize ...200212026974
diverse bacteria are pathogens of caenorhabditis elegans.practically and ethically attractive as model systems, invertebrate organisms are increasingly recognized as relevant for the study of bacterial pathogenesis. we show here that the nematode caenorhabditis elegans is susceptible to a surprisingly broad range of bacteria and may constitute a useful model for the study of both pathogens and symbionts.200212117988
crystal structures at atomic resolution reveal the novel concept of "electron-harvesting" as a role for the small tetraheme cytochrome c.the genus shewanella produces a unique small tetraheme cytochrome c that is implicated in the iron oxide respiration pathway. it is similar in heme content and redox potential to the well known cytochromes c(3) but related in structure to the cytochrome c domain of soluble fumarate reductases from shewanella sp. we report the crystal structure of the small tetraheme cytochrome c from shewanella oneidensis mr-1 in two crystal forms and two redox states. the overall fold and heme core are surprisi ...200212080059
microarray transcription profiling of a shewanella oneidensis etra mutant.dna microarrays were used to examine the effect of an insertional mutation in the shewanella oneidensis etra (electron transport regulator) locus on gene expression under anaerobic conditions. the mrna levels of 69 genes with documented functions in energy and carbon metabolism, regulation, transport, and other cellular processes displayed significant alterations in transcript abundance in an etra-mutant genetic background. this is the first microarray study indicating a possible involvement of ...200212142431
use of pcr-rflp for genotyping 16s rrna and characterizing bacteria cultured from halibut fry.small subunit ribosomal genes were explored using pcr-rflp to facilitate the characterization of bacteria cultured from reared fry of the atlantic halibut (hippoglossus hippoglossus). concern has been expressed about pathogen invasion in larvae lacking a counteracting normal flora that may aid the immune system in producing robust noninfected individuals. in this study, pure cultured representatives of normal flora that were previously found to be antagonistic towards a pathogenic vibrio sp. wer ...200212109877
impact of electrode composition on electricity generation in a single-compartment fuel cell using shewanella putrefaciens.the production of electricity by shewanella putrefaciens in the absence of exogenous electron acceptors was examined in a single compartment fuel cell with different types of electrodes and varying physiological conditions. electricity production was dependent on anode composition, electron donor type and cell concentration. a maximum current of 2.5 ma and a current density of 10.2 mw/m(2)electrode was obtained with a mn(4+) graphite anode, 200 mm sodium lactate and a cell concentration of 3.9 g ...200212073132
are cells viable at gigapascal pressures? 200212130751
enhancement of hematite bioreduction by natural organic matter.the effects of natural organic matter (nom), ferrozine, and aqds (anthraquinone-2,6-disulfonate) on the reduction of hematite (alpha-fe2o3) by shewanella putrefaciens cn32 were studied. it has been proposed that nom enhances the reduction of fe(iii) by means of electron shuttling or by fe(ii) complexation. previously both mechanisms were studied separately using "functional analogues" (aqds for electron shuttling and ferrozine for complexation) and are presently compared with seven different nom ...200212144265
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