Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| cloning and characterization of the gene encoding rna polymerase sigma factor sigma(54) of deep-sea piezophilic shewanella violacea. | we have recently reported that a sigma(54)-like factor recognizes a dna element, designated as region a, upstream of a pressure-regulated operon in piezophilic shewanella violacea strain dss12 (nakasone et al., fems microbiology lett. 176 (1999) 351-356). in this study, we isolated and characterized the rpon gene of this piezophilic bacterium. the rpon gene was found to encode a putative protein consisting of 492 amino acid residues with a predicted molecular mass of 55359 da. significant homolo ... | 2000 | 10760597 |
| expression of the transcripts of the sigma factors and putative sigma factor regulators of chlamydia trachomatis l2. | the steady state levels of the transcripts of the beta' subunit of rna polymerase gene (rpoc), three sigma factor genes (rpod, rpon, and rpsd), and four putative sigma factor regulatory genes (rsbw, rsbv1, rsbv2, and rsbu) of chlamydia trachomatis l2 were examined during the chlamydial developmental cycle by reverse transcription-polymerase chain reaction (rt-pcr) analysis. rpoc and the major sigma factor rpod transcripts were detected at all times post-infection, consistent with their expected ... | 2000 | 10773461 |
| pressure regulation of soluble cytochromes c in a deep-sea piezophilic bacterium, shewanella violacea. | two c-type cytochromes from the soluble fraction of a deep-sea moderately piezophilic bacterium, shewanella violacea, were purified and characterized, and the genes coding for these cytochromes were cloned and sequenced. one of the cytochromes, designated cytochrome c(a), was found to have a molecular mass of approximately 8.3 kda, and it contained one heme c per molecule. the other, designated cytochrome c(b), was found to have a molecular mass of approximately 23 kda, and it contained two heme ... | 2000 | 10781566 |
| a role for excreted quinones in extracellular electron transfer. | respiratory processes in bacteria are remarkable because of their ability to use a variety of compounds, including insoluble minerals, as terminal electron acceptors. although much is known about microbial electron transport to soluble electron acceptors, little is understood about electron transport to insoluble compounds such as ferric oxides. in anaerobic environments, humic substances can serve as electron acceptors and also as electron shuttles to ferric oxides. to explore this process, we ... | 2000 | 10811225 |
| reclassification of alteromonas distincta romanenko et al. 1995 as pseudoalteromonas distincta comb. nov. | the 16s rrna gene of alteromonas distincta kmm 638t was amplified, cloned and sequenced. the nucleotide sequence was aligned with sequences of representative strains of alteromonas, moritella, pseudoalteromonas and shewanella. results of phylogenetic analysis, using neighbour-joining and fitch-margoliash methods, clearly indicated that this species should be assigned to the genus pseudoalteromonas. on the basis of polyphasic data obtained from previous work and this study, it is proposed that th ... | 2000 | 10826797 |
| structural analysis of the ntrbc genes of deep-sea piezophilic shewanella violacea. | the ntrbc genes coding for the bacterial signal-transducing protein ntrb and the bacterial enhancer-binding protein ntrc of deep-sea piezophilic shewanella violacea were cloned and their nucleotide sequences were analyzed. the conserved regions of ntrb and those of ntrc are well conserved in the case of the ntrbc products of s. violacea. | 2000 | 10830521 |
| effect of temperature and salinity stress on growth and lipid composition of shewanella gelidimarina. | the maximum growth temperature, the optimal growth temperature, and the estimated normal physiological range for growth of shewanella gelidimarina are functions of water activity (a(w)), which can be manipulated by changing the concentration of sodium chloride. the growth temperatures at the boundaries of the normal physiological range for growth were characterized by increased variability in fatty acid composition. under hyper- and hypoosmotic stress conditions at an a(w) of 0.993 (1.0% [wt/vol ... | 2000 | 10831420 |
| effect of electron donor and solution chemistry on products of dissimilatory reduction of technetium by shewanella putrefaciens. | to help provide a fundamental basis for use of microbial dissimilatory reduction processes in separating or immobilizing (99)tc in waste or groundwaters, the effects of electron donor and the presence of the bicarbonate ion on the rate and extent of pertechnetate ion [tc(vii)o(4)(-)] enzymatic reduction by the subsurface metal-reducing bacterium shewanella putrefaciens cn32 were determined, and the forms of aqueous and solid-phase reduction products were evaluated through a combination of high-r ... | 2000 | 10831424 |
| enrichment of geobacter species in response to stimulation of fe(iii) reduction in sandy aquifer sediments. | engineered stimulation of fe(iii) has been proposed as a strategy to enhance the immobilization of radioactive and toxic metals in metal-contaminated subsurface environments. therefore, laboratory and field studies were conducted to determine which microbial populations would respond to stimulation of fe(iii) reduction in the sediments of sandy aquifers. in laboratory studies, the addition of either various organic electron donors or electron shuttle compounds stimulated fe(iii) reduction and re ... | 2000 | 10833228 |
| polyphasic taxonomic approach in the description of alishewanella fetalis gen. nov., sp. nov., isolated from a human foetus. | a taxonomically unique bacterium is described on the basis of a physiological and biochemical characterization, fatty acid profiling and sequence analyses of 16s rrna and gyrase b (gyrb) genes. this non-motile, non-fermentative bacterium was isolated from a human foetus in uppsala, sweden, and originally misidentified as a shewanella putrefaciens by conventional biochemical testing. the bacterium grew well at mesophilic temperatures with optimum growth at 37 degrees c. it was facultatively anaer ... | 2000 | 10843055 |
| identification of a novel gene, fimv, involved in twitching motility in pseudomonas aeruginosa. | transposon mutagenesis was used to identify a new locus required for twitching motility in pseudomonas aeruginosa. four tn5-b21 mutants which lacked twitching motility and a fifth which exhibited impaired motility were found to map to the same kpn:i restriction fragment at approximately 40 min on the p. aeruginosa genome. cloning and sequencing studies showed that all five transposon insertions occurred within the same 2.8 kb orf, which was termed fimv. the product of this gene has a putative pe ... | 2000 | 10846211 |
| do stresses encountered during the smoked salmon process influence the survival of the spoiling bacterium shewanella putrefaciens? | the influence of different treatments (i.e. cold, nacl, phenol and anaerobiosis) encountered during the smoked salmon process was studied by analysing the survival capacity of two shewanella putrefaciens strains (cip 69.29 and j13.1). our results indicated that only the salt stress was critical for the survival of s. putrefaciens. nevertheless, both strains of s. putrefaciens grown at low temperatures developed a cross-protection to a lethal nacl treatment. to our knowledge, this is the first re ... | 2000 | 10849272 |
| cyanobacterial sulfide-quinone reductase: cloning and heterologous expression. | the gene encoding sulfide-quinone reductase (sqr; e.c.1.8.5.'), the enzyme catalyzing the first step of anoxygenic photosynthesis in the filamentous cyanobacterium oscillatoria limnetica, was cloned by use of amino acid sequences of tryptic peptides as well as sequences conserved in the rhodobacter capsulatus sqr and in an open reading frame found in the genome of aquifex aeolicus. sqr activity was also detected in the unicellular cyanobacterium aphanothece halophytica following sulfide inductio ... | 2000 | 10852862 |
| identification and characterization of a novel cytochrome c(3) from shewanella frigidimarina that is involved in fe(iii) respiration. | shewanella frigidimarina ncimb400 is a non-fermenting, facultative anaerobe from the gamma group of proteobacteria. when grown anaerobically this organism produces a wide variety of periplasmic c-type cytochromes, mostly of unknown function. we have purified a small, acidic, low-potential tetrahaem cytochrome with similarities to the cytochromes c(3) from sulphate-reducing bacteria. the n-terminal sequence was used to design pcr primers and the ccta gene encoding cytochrome c(3) was isolated and ... | 2000 | 10861223 |
| a new bacterial white spot syndrome (bwss) in cultured tiger shrimp penaeus monodon and its comparison with white spot syndrome (wss) caused by virus. | this paper describes a new bacterial white spot syndrome (bwss) in cultured tiger shrimp penaeus monodon. the affected shrimp showed white spots similar to those caused by white spot syndrome virus (wssv), but the shrimp remained active and grew normally without significant mortalities. the study revealed no evidence of wssv infection using electron microscopy, histopathology and nested polymerase chain reaction. electron microscopy indicated bacteria associated with white spot formation, and wi ... | 2000 | 10907134 |
| applicability of an arrhenius model for the combined effect of temperature and co(2) packaging on the spoilage microflora of fish. | the temperature behavior of the natural microflora on the mediterranean fish red mullet (mullus barbatus) was examined as a case study. the growth of the spoilage bacteria pseudomonas spp., shewanella putrefaciens, brochothrix thermosphacta, and lactic acid bacteria was modeled as a function of temperature and the concentration of carbon dioxide in modified atmosphere packaging. combined models were developed and comparatively assessed based on polynomial, belehradek, and arrhenius equations. th ... | 2000 | 10919817 |
| a new class of glutamate dehydrogenases (gdh). biochemical and genetic characterization of the first member, the amp-requiring nad-specific gdh of streptomyces clavuligerus. | a new class of glutamate dehydrogenase (gdh) is reported. the gdh of streptomyces clavuligerus was purified to homogeneity and characterized. it has a native molecular mass of 1,100 kda and exists as an alpha(6) oligomeric structure composed of 183-kda subunits. gdh, which requires amp as an essential activator, shows a maximal rate of catalysis in 100 mm phosphate buffer, ph 7.0, at 30 degrees c. under these conditions, gdh displayed hyperbolic behavior toward ammonia (k(m), 33 mm) and sigmoida ... | 2000 | 10924516 |
| homogeneity of danish environmental and clinical isolates of shewanella algae. | danish isolates of shewanella algae constituted by whole-cell protein profiling a very homogeneous group, and no clear distinction was seen between strains from the marine environment and strains of clinical origin. although variation between all strains was observed by ribotyping and random amplified polymorphic dna analysis, no clonal relationship between infective strains was found. from several patients, clonally identical strains of s. algae were reisolated up to 8 months after the primary ... | 2000 | 10618264 |
| control of foodborne pathogens during sufu fermentation and aging. | control of the foodborne pathogens escherichia coli o157:h7, salmonella typhimurium, staphylococcus aureus, and listeria monocytogenes during sufu fermentation was evaluated. before fermentation, pathogens were inoculated onto tofu (substrate for sufu) at 5 log cfu/g or 3 log cfu/g, and starter culture (actinomucor elegans) was inoculated at 3 log cfu/g. after 2 days of fermentation at 30 degrees c, the four pathogens reached 7 to 9 log cfu/g, and the mold count reached 6 to 7 log cfu/g. after f ... | 2000 | 11192025 |
| a new isolation method for labyrinthulids using a bacterium, psychrobacter phenylpyruvicus. | a new isolation method for labyrinthulids, marine microbes with spindle-shaped vegetative cells and gliding movement, is presented. the method for isolating labyrinthulids has been found to be more difficult and less reproducible than that for thraustochytrids, classified in the same order. so far serum seawater agar fortified with antibiotics has been proposed to be the best for isolation of labyrinthulids. the method presented here involves placing plant samples on an agar medium on which a ma ... | 2001 | 14961392 |
| in situ environmental cell-transmission electron microscopy study of microbial reduction of chromium(vi) using electron energy loss spectroscopy. | reduction of cr(vi) by the bacterium, shewanella oneidensis (previously classified shewanella putrefaciens strain mr-1), was studied by absorption spectrophotometry and in situ, environmental cell-transmission electron microscopy (ec-tem) coupled with electron energy loss spectroscopy (eels). bacteria from rinsed cultures were placed directly in the environmental cell of the transmission electron microscope and examined under 100 torr pressure. bright field ec-tem images show two distinct popula ... | 2001 | 12597792 |
| 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 ... | 2001 | 12024255 |
| role for outer membrane cytochromes omca and omcb of shewanella putrefaciens mr-1 in reduction of manganese dioxide. | shewanella putrefaciens mr-1 can use a wide variety of terminal electron acceptors for anaerobic respiration, including certain insoluble manganese and iron oxides. to examine whether the outer membrane (om) cytochromes of mr-1 play a role in mn(iv) and fe(iii) reduction, mutants lacking the om cytochrome omca or omcb were isolated by gene replacement. southern blotting and pcr confirmed replacement of the omca and omcb genes, respectively, and reverse transcription-pcr analysis demonstrated los ... | 2001 | 11133454 |
| the gdhb gene of pseudomonas aeruginosa encodes an arginine-inducible nad(+)-dependent glutamate dehydrogenase which is subject to allosteric regulation. | the nad(+)-dependent glutamate dehydrogenase (nad-gdh) from pseudomonas aeruginosa pao1 was purified, and its amino-terminal amino acid sequence was determined. this sequence information was used in identifying and cloning the encoding gdhb gene and its flanking regions. the molecular mass predicted from the derived sequence for the encoded nad-gdh was 182.6 kda, in close agreement with that determined from sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme (180 kda ... | 2001 | 11133942 |
| automated nanoflow liquid chromatography/tandem mass spectrometric identification of proteins from shewanella putrefaciens separated by two-dimensional polyacrylamide gel electrophoresis. | the implementation of nanoflow liquid chromatography offers unique opportunities for automation of proteomics research. we demonstrate that automated nanoflow lc/ms/ms allowed the unambiguous identification of proteins from the omnipotent bacterium shewanella putrefaciens, based on similarity searches against the completely determined genome of related microorganisms and against non-redundant databases. total protein extracts were separated by 2-dimensional polyacrylamide electrophoresis. only 1 ... | 2001 | 11135424 |
| porphyromonas gingivalis dpp-7 represents a novel type of dipeptidylpeptidase. | a novel dipeptidylpeptidase (dpp-7) was purified from the membrane fraction of porphyromonas gingivalis. this enzyme, with an apparent molecular mass of 76 kda, has the specificity for both aliphatic and aromatic residues in the p1 position. although it belongs to the serine class of peptidases, it does not resemble other known dipeptidylpeptidases. interestingly, the amino acid sequence around the putative active site serine residue shows significant similarity to the c-terminal region of the s ... | 2001 | 11096098 |
| 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 ... | 2001 | 11294641 |
| 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 ... | 2001 | 11311432 |
| 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. | 2001 | 11272827 |
| 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 ... | 2001 | 11272828 |
| 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 ... | 2001 | 11493693 |
| 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 ... | 2001 | 11231004 |
| 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. | 2001 | 11270646 |
| 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 ... | 2001 | 11281319 |
| 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 ... | 2001 | 11294349 |
| 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 ... | 2001 | 11319118 |
| 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 ... | 2001 | 11321532 |
| 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 ... | 2001 | 11322705 |
| 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 ... | 2001 | 11329715 |
| 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 ... | 2001 | 11330692 |
| 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 ... | 2001 | 11347607 |
| 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 ... | 2001 | 11348071 |
| 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 ... | 2001 | 11349281 |
| 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 ... | 2001 | 11706794 |
| 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 ... | 2001 | 11351723 |
| 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 ... | 2001 | 11351998 |
| 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 ... | 2001 | 11359008 |
| microbiology. how bacteria respire minerals. | 2001 | 11360987 | |
| 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 ... | 2001 | 11403404 |
| 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 ... | 2001 | 11411670 |
| identification of a plasmid-encoded gene from haemophilus ducreyi which confers nad independence. | members of the family pasteurellaceae are classified in part by whether or not they require an nad supplement for growth on laboratory media. in this study, we demonstrate that this phenotype can be determined by a single gene, nadv, whose presence allows nad-independent growth of haemophilus influenzae and actinobacillus pleuropneumoniae. this gene was cloned from a 5.2-kb plasmid which was previously shown to be responsible for nad independence in haemophilus ducreyi. when transformed into a. ... | 2001 | 11157928 |
| mtrc, an outer membrane decahaem c cytochrome required for metal reduction in shewanella putrefaciens mr-1. | shewanella putrefaciens is a facultative anaerobe that can use metal oxides as terminal electron acceptors during anaerobic respiration. two proteins, mtrb and cct, have been identified that are specifically involved in metal reduction. analysis of s. putrefaciens mutants deficient in metal reduction led to the identification of two additional proteins that are involved in this process. mtra is a periplasmic decahaem c-type cytochrome that appears to be part of the electron transport chain, whic ... | 2001 | 11169112 |
| the biotechnological potential of piezophiles. | microorganisms that prefer high-pressure conditions are termed piezophiles (previously termed barophiles). the molecular basis of piezophily is now being investigated extensively focusing on aspects of gene regulation and the function of certain proteins in deep-sea isolates. little attention has been paid, however, to the potential biotechnological applications of piezophiles compared with other extremophiles. based on the fundamental knowledge available, we will try to answer the following que ... | 2001 | 11179803 |
| 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 ... | 2001 | 11466298 |
| 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 ... | 2001 | 11209061 |
| 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 ... | 2001 | 11425747 |
| 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 ... | 2001 | 11428576 |
| 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 ... | 2001 | 11432552 |
| 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; ... | 2001 | 11452122 |
| 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 ... | 2001 | 11453464 |
| 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 ... | 2001 | 11470375 |
| 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 ... | 2001 | 11809928 |
| 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 ... | 2001 | 11775166 |
| 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 ... | 2001 | 11495987 |
| 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 ... | 2001 | 11525631 |
| 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 ... | 2001 | 11545211 |
| 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 ... | 2001 | 11576688 |
| 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 ... | 2001 | 11591148 |
| 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 ... | 2001 | 11601699 |
| 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 ... | 2001 | 11703190 |
| 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 ... | 2001 | 11722905 |
| 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. | 2001 | 11728048 |
| 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 ... | 2001 | 11876370 |
| mutations that affect agrobacterium vitis-induced grape necrosis also alter its ability to cause a hypersensitive response on tobacco. | abstract tn5-induced mutations in agrobacterium vitis f2/5 resulted in both altered grape necrosis and tobacco leaf panel collapse phenotypes, suggesting that the underlying mechanisms of the reactions are related. the reaction on tobacco resembles the classical hypersensitive response (hr) caused by several plant pathogenic bacteria in that it is observable within 14 h, is inhibited by treatment of plants with metabolic inhibitors, and results in the inability to recover the pathogen from the n ... | 2001 | 18944123 |
| biosynthesis of polyunsaturated fatty acids by polyketide synthases. | 2002 | 19750617 | |
| 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 ... | 2002 | 11878564 |
| 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 ... | 2002 | 11881834 |
| 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 ... | 2002 | 11899050 |
| 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 ... | 2002 | 11934298 |
| 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. | 2002 | 12117988 |
| are cells viable at gigapascal pressures? | 2002 | 12130751 | |
| 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 ... | 2002 | 11943357 |
| 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 ... | 2002 | 11955059 |
| the structure of the carbohydrate backbone of the lps from shewanella putrefaciens cn32. | the lipopolysaccharide (lps) from a natural rough strain of shewanella putrefaciens cn32 was analyzed using nmr and mass spectroscopy and chemical methods, and the following structure of its carbohydrate backbone is proposed: beta-galf-(1-->3)-beta-gal-(1-->4)-beta-glc-(1-->4)-alpha-ddhep2petn-(1-->5)-alpha-kdo4p-(1-->6)-beta-glcn4p-(1-->6)-alpha-glcn1p | 2002 | 12151208 |
| 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 ... | 2002 | 11961561 |
| 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. | 2002 | 11972695 |
| 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. | 2002 | 11972700 |
| 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 ... | 2002 | 11976119 |
| characterization of the lipopolysaccharides and capsules of shewanella spp. | electron microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis with silver staining and (1)h, (13)c, and (31)p-nuclear magnetic resonance (nmr) were used to detect and characterize the lipopolysaccharides (lpss) of several shewanella species. many expressed only rough lps; however, approximately one-half produced smooth lps (and/or capsular polysaccharides). some lpss were affected by growth temperature with increased chain length observed below 25 degrees c. maximum lps heteroge ... | 2002 | 12200327 |
| 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 ... | 2002 | 11997161 |
| 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). ... | 2002 | 11999050 |
| 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 ... | 2002 | 12001169 |
| geobiologists: as diverse as the bugs they study. | 2002 | 12004114 | |
| 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 ... | 2002 | 12010043 |
| 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 ... | 2002 | 12013439 |
| 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 ... | 2002 | 11741854 |
| 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 ... | 2002 | 11751771 |
| 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 ... | 2002 | 11872738 |
| 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 ... | 2002 | 11778045 |
| 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 ... | 2002 | 11811482 |