| identification of a streptogramin a acetyltransferase gene in the chromosome of yersinia enterocolitica. | streptogramins are polypeptide antibiotics inhibiting protein synthesis by the prokaryotic ribosome. gram-positive organisms are susceptible to streptogramins, while most gram-negative bacteria are intrinsically resistant. we have found a genomic fragment from a yersinia enterocolitica isolate with an open reading frame coding for a polypeptide similar to the virginiamycin acetyltransferases found in various plasmids from gram-positive bacteria. the susceptible escherichia coli strain db10 was t ... | 2000 | 10722489 |
| chromium(vi) reductase activity is associated with the cytoplasmic membrane of anaerobically grown shewanella putrefaciens mr-1. | shewanella putrefaciens mr-1 can reduce a diverse array of compounds under anaerobic conditions, including manganese and iron oxides, fumarate, nitrate, and many other compounds. these reductive processes are apparently linked to a complex electron transport system. chromium (cr) is a toxic and mutagenic metal and bacteria could potentially be utilized to immobilize cr by reducing the soluble and bioavailable state, cr(vi), to the insoluble and less bioavailable state, cr(iii). formate-dependent ... | 2000 | 10735248 |
| peptidase e, a peptidase specific for n-terminal aspartic dipeptides, is a serine hydrolase. | salmonella enterica serovar typhimurium peptidase e (pepe) is an n-terminal asp-specific dipeptidase. pepe is not inhibited by any of the classical peptidase inhibitors, and its amino acid sequence does not place it in any of the known peptidase structural classes. a comparison of the amino acid sequence of pepe with a number of related sequences has allowed us to define the amino acid residues that are strongly conserved in this family. to ensure the validity of this comparison, we have express ... | 2000 | 10762256 |
| reduction of fe(iii), cr(vi), u(vi), and tc(vii) by deinococcus radiodurans r1. | deinococcus radiodurans is an exceptionally radiation-resistant microorganism capable of surviving acute exposures to ionizing radiation doses of 15,000 gy and previously described as having a strictly aerobic respiratory metabolism. under strict anaerobic conditions, d. radiodurans r1 reduced fe(iii)-nitrilotriacetic acid coupled to the oxidation of lactate to co(2) and acetate but was unable to link this process to growth. d. radiodurans reduced the humic acid analog anthraquinone-2,6-disulfon ... | 2000 | 10788374 |
| targeted disruption of the kstd gene encoding a 3-ketosteroid delta(1)-dehydrogenase isoenzyme of rhodococcus erythropolis strain sq1. | microbial phytosterol degradation is accompanied by the formation of steroid pathway intermediates, which are potential precursors in the synthesis of bioactive steroids. degradation of these steroid intermediates is initiated by delta(1)-dehydrogenation of the steroid ring structure. characterization of a 2.9-kb dna fragment of rhodococcus erythropolis sq1 revealed an open reading frame (kstd) showing similarity with known 3-ketosteroid delta(1)-dehydrogenase genes. heterologous expression of k ... | 2000 | 10788377 |
| bacteriology of infected cavitating lung tumor. | differentiation between in situ infection and simple tumor necrosis in cavitating lung tumors by means of imaging studies is difficult. in this study, we prospectively investigated the role of ultrasound (us)-guided transthoracic aspiration for bacteriologic examination of infected cavitating lung tumors, and the influence of the culture results on the treatment of patients. twenty-two patients (18 men and four women) with cavitating lung tumors treated from january 1996 to october 1998 were inc ... | 2000 | 10806182 |
| a membrane-bound flavocytochrome c-sulfide dehydrogenase from the purple phototrophic sulfur bacterium ectothiorhodospira vacuolata. | the amino acid sequence of ectothiorhodospira vacuolata cytochrome c-552, isolated from membranes with n-butanol, shows that it is a protein of 77 amino acid residues with a molecular mass of 9,041 da. it is closely related to the cytochrome subunit of chlorobium limicola f. sp. thiosulfatophilum flavocytochrome c-sulfide dehydrogenase (fcsd), having 49% identity. these data allowed isolation of a 5.5-kb subgenomic clone which contains the cytochrome gene and an adjacent flavoprotein gene as in ... | 2000 | 10809687 |
| 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 |
| domain organization and flavin adenine dinucleotide-binding determinants in the aerotaxis signal transducer aer of escherichia coli. | aerotactic responses in escherichia coli are mediated by the membrane transducer aer, a recently identified member of the superfamily of pas domain proteins, which includes sensors of light, oxygen, and redox state. initial studies of aer suggested that it might use a flavin adenine dinucleotide (fad) prosthetic group to monitor cellular redox changes. to test this idea, we purified lauryl maltoside-solubilized aer protein by his-tag affinity chromatography and showed by high performance liquid ... | 2000 | 10811894 |
| crystal structures of an oxygen-binding cytochrome c from rhodobacter sphaeroides. | the photosynthetic bacterium rhodobacter sphaeroides produces a heme protein (shp), which is an unusual c-type cytochrome capable of transiently binding oxygen during autooxidation. similar proteins have not only been observed in other photosynthetic bacteria but also in the obligate methylotroph methylophilus methylotrophus and the metal reducing bacterium shewanella putrefaciens. a three-dimensional structure of shp was derived using the multiple isomorphous replacement phasing method. besides ... | 2000 | 10821858 |
| 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 |
| 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 |
| salmonella enterica serovar typhimurium peptidase b is a leucyl aminopeptidase with specificity for acidic amino acids. | peptidase b (pepb) of salmonella enterica serovar typhimurium is one of three broad-specificity aminopeptidases found in this organism. we have sequenced the pepb gene and found that it encodes a 427-amino-acid (46.36-kda) protein, which can be unambiguously assigned to the leucyl aminopeptidase (lap) structural family. pepb has been overexpressed and purified. the active enzyme shows many similarities to other members of the lap family: it is a heat-stable (70 degrees c; 20 min) hexameric ( app ... | 2000 | 10852868 |
| exopolysaccharide production is required for development of escherichia coli k-12 biofilm architecture. | although exopolysaccharides (epss) are a large component of bacterial biofilms, their contribution to biofilm structure and function has been examined for only a few organisms. in each of these cases eps has been shown to be required for cellular attachment to abiotic surfaces. here, we undertook a genetic approach to examine the potential role of colanic acid, an eps of escherichia coli k-12, in biofilm formation. strains either proficient or deficient in colanic acid production were grown and ... | 2000 | 10852895 |
| a new klebsiella planticola strain (cd-1) grows anaerobically at high cadmium concentrations and precipitates cadmium sulfide. | heavy metal resistance by bacteria is a topic of much importance to the bioremediation of contaminated soils and sediments. we report here the isolation of a highly cadmium-resistant klebsiella planticola strain, cd-1, from reducing salt marsh sediments. the strain grows in up to 15 mm cdcl(2) under a wide range of nacl concentrations and at acidic or neutral ph. in growth medium amended with thiosulfate, it precipitated significant amounts of cadmium sulfide (cds), as confirmed by x-absorption ... | 2000 | 10877810 |
| the bacterial cell-division protein zipa and its interaction with an ftsz fragment revealed by x-ray crystallography. | in escherichia coli, ftsz, a homologue of eukaryotic tubulins, and zipa, a membrane-anchored protein that binds to ftsz, are two essential components of the septal ring structure that mediates cell division. recent data indicate that zipa is involved in the assembly of the ring by linking ftsz to the cytoplasmic membrane and that the zipa-ftsz interaction is mediated by their c-terminal domains. we present the x-ray crystal structures of the c-terminal ftsz-binding domain of zipa and a complex b ... | 2000 | 10880432 |
| 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 |
| human infection with halomonas venusta following fish bite. | halomonas venusta, a moderately halophilic, nonfermentative gram-negative rod, is reported for the first time as a human pathogen in a wound that originated from a fish bite. | 2000 | 10921995 |
| molecular characterization of the beta-n-acetylglucosaminidase of escherichia coli and its role in cell wall recycling. | the beta-n-acetylglucosaminidase of escherichia coli was found to have a novel specificity and to be encoded by a gene (nagz) that maps at 25.1 min. it corresponds to an open reading frame, ycfo, whose predicted amino acid sequence is 57% identical to that of vibrio furnissii exoii. nagz hydrolyzes the beta-1,4 glycosidic bond between n-acetylglucosamine and anhydro-n-acetylmuramic acid in cell wall degradation products following their importation into the cell during the process for recycling c ... | 2000 | 10940025 |
| design and application of a rapid screening technique for isolation of selenite reduction-deficient mutants of shewanella putrefaciens. | a rapid screening technique for isolation of selenite (se(iv)) reduction-deficient (ser) mutants was developed and used to identify four ser mutants of shewanella putrefaciens. two ser mutants were unable to grow anaerobically on fumarate, nitrate or nitrite. two other ser mutants were unable to grow anaerobically on all compounds tested as sole terminal electron acceptor. previously isolated mn(iv) reduction-deficient mutants displayed ser-positive phenotypes and reduced se(iv) at wild-type rat ... | 2000 | 10950189 |
| fe(iii) reduction activity and cytochrome content of shewanella putrefaciens grown on ten compounds as sole terminal electron acceptor. | shewanella putrefaciens was grown on a series of ten alternate compounds as sole terminal electron acceptor. each cell type was analyzed for fe(iii) reduction activity, absorbance maxima in reduced-minus-oxidized difference spectra and heme-containing protein content. high-rate fe(iii) reduction activity, pronounced difference maxima at 521 and 551 nm and a predominant 29.3 kda heme-containing protein expressed by cells grown on fe(iii), mn(iv), u(vi), so3(2-) and s2o3(2-), but not by cells grow ... | 2000 | 10950190 |
| modeling reduction of uranium u(vi) under variable sulfate concentrations by sulfate-reducing bacteria. | the kinetics for the reduction of sulfate alone and for concurrent uranium [u(vi)] and sulfate reduction, by mixed and pure cultures of sulfate-reducing bacteria (srb) at 21 +/- 3 degrees c were studied. the mixed culture contained the srb desulfovibrio vulgaris along with a clostridium sp. determined via 16s ribosomal dna analysis. the pure culture was desulfovibrio desulfuricans (atcc 7757). a zero-order model best fit the data for the reduction of sulfate from 0.1 to 10 mm. a lag time occurre ... | 2000 | 10966381 |
| direct and fe(ii)-mediated reduction of technetium by fe(iii)-reducing bacteria. | the dissimilatory fe(iii)-reducing bacterium geobacter sulfurreducens reduced and precipitated tc(vii) by two mechanisms. washed cell suspensions coupled the oxidation of hydrogen to enzymatic reduction of tc(vii) to tc(iv), leading to the precipitation of tco(2) at the periphery of the cell. an indirect, fe(ii)-mediated mechanism was also identified. acetate, although not utilized efficiently as an electron donor for direct cell-mediated reduction of technetium, supported the reduction of fe(ii ... | 2000 | 10966385 |
| expression of a tetraheme protein, desulfovibrio vulgaris miyazaki f cytochrome c(3), in shewanella oneidensis mr-1. | cytochrome c(3) from desulfovibrio vulgaris miyazaki f was successfully expressed in the facultative aerobe shewanella oneidensis mr-1 under anaerobic, microaerophilic, and aerobic conditions, with yields of 0.3 to 0.5 mg of cytochrome/g of cells. a derivative of the broad-host-range plasmid prk415 containing the cytochrome c(3) gene from d. vulgaris miyazaki f was used for transformation of s. oneidensis mr-1, resulting in the production of protein product that was indistinguishable from that p ... | 2000 | 10966450 |
| application of a systematic experimental procedure to develop a microbial model for rapid fish shelf life predictions. | a systematic experimental procedure for fish shelf-life modelling was used to develop a model for predicting the quality of fish in the chill chain. for this, the growth of the naturally occurring bacteria pseudomonads, shewanella putrefaciens, enterobacteriaceae, lactic acid bacteria and yeasts, on gilt-head seabream (sparus aurata), was studied at temperatures from 0 to 15 degrees c. the results from the microbiological, organoleptical and chemical analysis conducted on naturally contaminated ... | 2000 | 11016607 |
| 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 | 11029011 |
| detection and identification of mycobacteria by amplification of the internal transcribed spacer regions with genus- and species-specific pcr primers. | we evaluated the usefulness of pcr assays that target the internal transcribed spacer (its) region for identifying mycobacteria at the species level. the conservative and species-specific its sequences of 33 species of mycobacteria were analyzed in a multialignment analysis. one pair of panmycobacterial primers and seven pairs of mycobacterial species-specific primers were designed. all pcrs were performed under the same conditions. the specificities of the primers were tested with type strains ... | 2000 | 11060072 |
| s-adenosylmethionine decarboxylase from the archaeon methanococcus jannaschii: identification of a novel family of pyruvoyl enzymes. | polyamines are present in high concentrations in archaea, yet little is known about their synthesis, except by extrapolation from bacterial and eucaryal systems. s-adenosylmethionine (adomet) decarboxylase, a pyruvoyl group-containing enzyme that is required for spermidine biosynthesis, has been previously identified in eucarya and escherichia coli. despite spermidine concentrations in the methanococcales that are several times higher than in e. coli, no adomet decarboxylase gene was recognized ... | 2000 | 11073910 |
| the synergistic effect of excimer and low-pressure mercury lamps on the disinfection of flowing water. | microorganisms in flowing water were disinfected by uv radiation from two excimer (excited dimer) lamps (emitting at 172 and 222 nm) in combination with two low-pressure mercury lamps (emitting at 254 nm). synergies were investigated among the three types of radiation in the treatment of water spiked in turn with escherichia coli, listeria innocua, shewanella putrefaciens, and spores of bacillus subtilis and bacillus cereus. synergy was demonstrated between radiations at 222 and 254 nm in the tr ... | 2000 | 11079695 |
| evidence for horizontal gene transfer in evolution of elongation factor tu in enterococci. | the elongation factor tu, encoded by tuf genes, is a gtp binding protein that plays a central role in protein synthesis. one to three tuf genes per genome are present, depending on the bacterial species. most low-g+c-content gram-positive bacteria carry only one tuf gene. we have designed degenerate pcr primers derived from consensus sequences of the tuf gene to amplify partial tuf sequences from 17 enterococcal species and other phylogenetically related species. the amplified dna fragments were ... | 2000 | 11092850 |
| 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 |
| the structure of aspartyl dipeptidase reveals a unique fold with a ser-his-glu catalytic triad. | the three-dimensional structure of salmonella typhimurium aspartyl dipeptidase, peptidase e, was solved crystallographically and refined to 1.2-a resolution. the structure of this 25-kda enzyme consists of two mixed beta-sheets forming a v, flanked by six alpha-helices. the active site contains a ser-his-glu catalytic triad and is the first example of a serine peptidase/protease with a glutamate in the catalytic triad. the active site ser is located on a strand-helix motif reminiscent of that fo ... | 2000 | 11106384 |
| characterization of a streptococcal endopeptidase with homology to human endothelin-converting enzyme. | a gene encoding an endopeptidase from streptococcus parasanguis fw213 has been cloned and shown to have high sequence homology to genes encoding mammalian metalloendopeptidases. the gene, designated s. parasanguis pepo, was cloned into the pet28a expression vector, resulting in a fusion of vector sequences encoding a hexahistidine tag at the carboxyl terminus. the recombinant pepo (rpepo) was expressed in escherichia coli and purified using an ni(2+) affinity column. polyclonal antiserum to rpep ... | 2001 | 11119489 |
| 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 |
| genetic and physiological characterization of ohr, encoding a protein involved in organic hydroperoxide resistance in pseudomonas aeruginosa. | the ohr (organic hydroperoxide resistance) gene product of pseudomonas aeruginosa was essential for optimal resistance to organic hydroperoxides (ohps) but not to hydrogen peroxide or paraquat. a deltaohr mutant was hypersusceptible to ohps in disk inhibition assays and showed enhanced killing by ohps in liquid culture. the ohr gene product was demonstrated to contribute to the decomposition of ohps. transcription of ohr was induced up to 15-fold upon exposure to ohps, and this induction was ind ... | 2001 | 11133975 |
| 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 |
| shewanella putrefaciens hand infection. | | 2000 | 11147445 |
| formation of chromosomal tandem arrays of the sxt element and r391, two conjugative chromosomally integrating elements that share an attachment site. | the sxt element, a conjugative, self-transmissible, integrating element (a constin) originally derived from a vibrio cholerae o139 isolate from india, and incj element r391, originally derived from a south african providencia rettgeri isolate, were found to be genetically and functionally related. both of these constins integrate site specifically into the escherichia coli chromosome at an identical attachment site within the 5' end of prfc. they encode nearly identical integrases, which are req ... | 2001 | 11157923 |
| 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 |
| quinone profiles of thermoplasma acidophilum ho-62. | quinones of thermoplasma acidophilum ho-62 were analyzed by high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance. menaquinone, methionaquinone, and 2-trans and 2-cis forms of thermoplasmaquinone were identified. the relative amount of thermoplasmaquinone increased under anaerobic conditions, and those of menaquinone and methionaquinone increased under aerobic conditions. | 2001 | 11157962 |
| phylogenetic footprinting of transcription factor binding sites in proteobacterial genomes. | toward the goal of identifying complete sets of transcription factor (tf)-binding sites in the genomes of several gamma proteobacteria, and hence describing their transcription regulatory networks, we present a phylogenetic footprinting method for identifying these sites. probable transcription regulatory sites upstream of escherichia coli genes were identified by cross-species comparison using an extended gibbs sampling algorithm. close examination of a study set of 184 genes with documented tr ... | 2001 | 11160901 |
| 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 |
| 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 |
| 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 |
| phenotypic methods for determining genomovar status of the burkholderia cepacia complex. | recent taxonomic advances have demonstrated that burkholderia cepacia is a cluster of at least seven closely related genomic species (or genomovars) collectively referred to as the b. cepacia complex, all of which may cause infections among cystic fibrosis patients and other vulnerable individuals. thus, it is important for clinical microbiologists to be able to differentiate genomovars. prior to this study, 361 b. cepacia complex isolates and 51 isolates easily confused with b. cepacia complex ... | 2001 | 11230429 |
| genome of the extremely radiation-resistant bacterium deinococcus radiodurans viewed from the perspective of comparative genomics. | the bacterium deinococcus radiodurans shows remarkable resistance to a range of damage caused by ionizing radiation, desiccation, uv radiation, oxidizing agents, and electrophilic mutagens. d. radiodurans is best known for its extreme resistance to ionizing radiation; not only can it grow continuously in the presence of chronic radiation (6 kilorads/h), but also it can survive acute exposures to gamma radiation exceeding 1,500 kilorads without dying or undergoing induced mutation. these characte ... | 2001 | 11238985 |
| characterization of the d-xylulose 5-phosphate/d-fructose 6-phosphate phosphoketolase gene (xfp) from bifidobacterium lactis. | a d-xylulose 5-phosphate/d-fructose 6-phosphate phosphoketolase (xfp) from the probiotic bifidobacterium lactis was purified to homogeneity. the specific activity of the purified enzyme with d-fructose 6-phosphate as a substrate is 4.28 units per mg of enzyme. k(m) values for d-xylulose 5-phosphate and d-fructose 6-phosphate are 45 and 10 mm, respectively. the native enzyme has a molecular mass of 550,000 da. the subunit size upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis (90,000 ... | 2001 | 11292814 |
| 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 |
| 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 |
| the complete genome sequence of the lactic acid bacterium lactococcus lactis ssp. lactis il1403. | lactococcus lactis is a nonpathogenic at-rich gram-positive bacterium closely related to the genus streptococcus and is the most commonly used cheese starter. it is also the best-characterized lactic acid bacterium. we sequenced the genome of the laboratory strain il1403, using a novel two-step strategy that comprises diagnostic sequencing of the entire genome and a shotgun polishing step. the genome contains 2,365,589 base pairs and encodes 2310 proteins, including 293 protein-coding genes belo ... | 2001 | 11337471 |
| 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 |
| bacteria mediate methylation of iodine in marine and terrestrial environments. | methyl iodide (ch(3)i) plays an important role in the natural iodine cycle and participates in atmospheric ozone destruction. however, the main source of this compound in nature is still unclear. here we report that a wide variety of bacteria including terrestrial and marine bacteria are capable of methylating the environmental level of iodide (0.1 microm). of the strains tested, rhizobium sp. strain mrcd 19 was chosen for further analysis, and it was found that the cell extract catalyzed the me ... | 2001 | 11375186 |
| photosynthetic and phylogenetic primers for detection of anoxygenic phototrophs in natural environments. | primer sets were designed to target specific 16s ribosomal dna (rdna) sequences of photosynthetic bacteria, including the green sulfur bacteria, the green nonsulfur bacteria, and the members of the heliobacteriaceae (a gram-positive phylum). due to the phylogenetic diversity of purple sulfur and purple nonsulfur phototrophs, the 16s rdna gene was not an appropriate target for phylogenetic rdna primers. thus, a primer set was designed that targets the pufm gene, encoding the m subunit of the phot ... | 2001 | 11425703 |
| 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 |
| isolation and characterization of a soluble nadph-dependent fe(iii) reductase from geobacter sulfurreducens. | nadph is an intermediate in the oxidation of organic compounds coupled to fe(iii) reduction in geobacter species, but fe(iii) reduction with nadph as the electron donor has not been studied in these organisms. crude extracts of geobacter sulfurreducens catalyzed the nadph-dependent reduction of fe(iii)-nitrilotriacetic acid (nta). the responsible enzyme, which was recovered in the soluble protein fraction, was purified to apparent homogeneity in a four-step procedure. its specific activity for f ... | 2001 | 11443080 |
| diversity in antistaphylococcal mechanisms among membrane-targeting antimicrobial peptides. | many antimicrobial peptides permeabilize the bacterial cytoplasmic membrane. however, it is unclear how membrane permeabilization and antimicrobial activity are related for distinct peptides. this study investigated the relationship between staphylococcus aureus membrane permeabilization and cell death due to the following antistaphylococcal peptides: thrombin-induced platelet microbicidal protein 1 (tpmp-1), gramicidin d, and protamine. isogenic s. aureus strains isp479c and isp479r (tpmp-1 sus ... | 2001 | 11447168 |
| 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 |
| non-canonical mechanism for translational control in bacteria: synthesis of ribosomal protein s1. | translation initiation region (tir) of the rpsa mrna encoding ribosomal protein s1 is one of the most efficient in escherichia coli despite the absence of a canonical shine-dalgarno-element. its high efficiency is under strong negative autogenous control, a puzzling phenomenon as s1 has no strict sequence specificity. to define sequence and structural elements responsible for translational efficiency and autoregulation of the rpsa mrna, a series of rpsa'-'lacz chromosomal fusions bearing various ... | 2001 | 11483525 |
| 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 |
| sodium ion cycle in bacterial pathogens: evidence from cross-genome comparisons. | analysis of the bacterial genome sequences shows that many human and animal pathogens encode primary membrane na+ pumps, na+-transporting dicarboxylate decarboxylases or na+ translocating nadh:ubiquinone oxidoreductase, and a number of na+ -dependent permeases. this indicates that these bacteria can utilize na+ as a coupling ion instead of or in addition to the h+ cycle. this capability to use a na+ cycle might be an important virulence factor for such pathogens as vibrio cholerae, neisseria men ... | 2001 | 11528000 |
| the emerging periplasm-localized subclass of aroq chorismate mutases, exemplified by those from salmonella typhimurium and pseudomonas aeruginosa. | chorismate mutases of the aroq homology class are widespread in the bacteria and the archaea. many of these exist as domains that are fused with other aromatic-pathway catalytic domains. among the monofunctional aroq proteins, that from erwinia herbicola was previously shown to have a cleavable signal peptide and located in the periplasmic compartment. whether or not this might be unique to e. herbicola was unknown. | 2001 | 11532214 |
| 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 ... | 1995 | 11539843 |
| essential role for estrogen in protection against vibrio vulnificus-induced endotoxic shock. | little is known about the underlying mechanisms that result in a sexually dimorphic response to vibrio vulnificus endotoxic shock. v. vulnificus is a gram-negative bacterium, considered one of the most invasive and rapidly fatal human pathogens known. however, 85% of individuals that develop endotoxic shock from v. vulnificus are males. using the rat, we have developed a model for v. vulnificus endotoxic shock that mimics the sexually dimorphic response in humans. gonadectomy in females results ... | 2001 | 11553550 |
| reduction of technetium(vii) by desulfovibrio fructosovorans is mediated by the nickel-iron hydrogenase. | resting cells of the sulfate-reducing bacterium desulfovibrio fructosovorans grown in the absence of sulfate had a very high tc(vii)-reducing activity, which led to the formation of an insoluble black precipitate. the involvement of a periplasmic hydrogenase in tc(vii) reduction was indicated (i) by the requirement for hydrogen as an electron donor, (ii) by the tolerance of this activity to oxygen, and (iii) by the inhibition of this activity by cu(ii). moreover, a mutant carrying a deletion in ... | 2001 | 11571159 |
| pb(ii) distributions at biofilm-metal oxide interfaces. | the distribution of aqueous pb(ii) sorbed at the interface between burkholderia cepacia biofilms and hematite (alpha-fe(2)o(3)) or corundum (alpha-al(2)o(3)) surfaces has been probed by using an application of the long-period x-ray standing wave technique. attached bacteria and adsorbed organic matter may interfere with sorption processes on metal oxide surfaces by changing the characteristics of the electrical double layer at the solid-solution interface, blocking surface sites, or providing a ... | 2001 | 11572932 |
| dna as a nutrient: novel role for bacterial competence gene homologs. | the uptake and stable maintenance of extracellular dna, genetic transformation, is universally recognized as a major force in microbial evolution. we show here that extracellular dna, both homospecific and heterospecific, can also serve as the sole source of carbon and energy supporting microbial growth. mutants unable to consume dna suffer a significant loss of fitness during stationary-phase competition. in escherichia coli, the use of dna as a nutrient depends on homologs of proteins involved ... | 2001 | 11591672 |
| the esat-6 gene cluster of mycobacterium tuberculosis and other high g+c gram-positive bacteria. | the genome of mycobacterium tuberculosis h37rv has five copies of a cluster of genes known as the esat-6 loci. these clusters contain members of the cfp-10 (lhp) and esat-6 (esat-6) gene families (encoding secreted t-cell antigens that lack detectable secretion signals) as well as genes encoding secreted, cell-wall-associated subtilisin-like serine proteases, putative abc transporters, atp-binding proteins and other membrane-associated proteins. these membrane-associated and energy-providing pro ... | 2001 | 11597336 |
| molecular analysis of antibiotic resistance gene clusters in vibrio cholerae o139 and o1 sxt constins. | many recent asian clinical vibrio cholerae e1 tor o1 and o139 isolates are resistant to the antibiotics sulfamethoxazole (su), trimethoprim (tm), chloramphenicol (cm), and streptomycin (sm). the corresponding resistance genes are located on large conjugative elements (sxt constins) that are integrated into prfc on the v. cholerae chromosome. we determined the dna sequences of the antibiotic resistance genes in the sxt constin in mo10, an o139 isolate. in sxt(mo10), these genes are clustered with ... | 2001 | 11600347 |
| integron integrases possess a unique additional domain necessary for activity. | integrons are genetic elements capable of integrating genes by a site-specific recombination system catalyzed by an integrase. integron integrases are members of the tyrosine recombinase family and possess the four invariant residues (rhry) and conserved motifs (boxes i and ii and patches i, ii, and iii). an alignment of integron integrases compared to other tyrosine recombinases shows an additional group of residues around the patch iii motif. we have analyzed the dna binding and recombination ... | 2001 | 11673443 |
| the high-molecular-weight cytochrome c cyc2 of acidithiobacillus ferrooxidans is an outer membrane protein. | a high-molecular-weight c-type cytochrome, cyc2, and a putative 22-kda c-type cytochrome were detected in the membrane fraction released during spheroplast formation from acidithiobacillus ferrooxidans. this fraction was enriched in outer membrane components and devoid of cytoplasmic membrane markers. the genetics, as well as the subcellular localization of cyc2 at the outer membrane level, therefore make it a prime candidate for the initial electron acceptor in the respiratory pathway between f ... | 2002 | 11741873 |
| 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 |
| characterization of pseudomonas spp. associated with spoilage of gilt-head sea bream stored under various conditions. | the population dynamics of pseudomonads in gilt-head sea bream mediterranean fish (sparus aurata) stored under different conditions were studied. phenotypic analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell proteins were performed to identify a total of 106 pseudomonas strains isolated from s. aurata stored under different temperatures (at 0, 10, and 20 degrees c) and packaging conditions (air and a modified atmosphere of 40% co(2)-30% n(2)-30% o(2)). pseudomon ... | 2002 | 11772610 |
| identification of the 2-methylcitrate pathway involved in the catabolism of propionate in the polyhydroxyalkanoate-producing strain burkholderia sacchari ipt101(t) and analysis of a mutant accumulating a copolyester with higher 3-hydroxyvalerate content. | burkholderia sacchari ipt101(t) induced the formation of 2-methylcitrate synthase and 2-methylisocitrate lyase when it was cultivated in the presence of propionic acid. the prp locus of b. sacchari ipt101(t) is required for utilization of propionic acid as a sole carbon source and is relevant for incorporation of 3-hydroxyvalerate (3hv) into copolyesters, and it was cloned and sequenced. five genes (prpr, prpb, prpc, acnm, and orf5) exhibited identity to genes located in the prp loci of other gr ... | 2002 | 11772636 |
| ohr, encoding an organic hydroperoxide reductase, is an in vivo-induced gene in actinobacillus pleuropneumoniae. | actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia, a disease characterized by pulmonary necrosis and hemorrhage caused in part by neutrophil degranulation. in an effort to understand the pathogenesis of this disease, we have developed an in vivo expression technology (ivet) system to identify genes that are specifically up-regulated during infection. one of the genes that we have identified as being induced in vivo is ohr, encoding organic hydroperoxide reductase, ... | 2002 | 11796613 |
| 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 |
| comparative analysis of fur regulons in gamma-proteobacteria. | iron is an essential element for the survival and pathogenesis of bacteria. the strict control of iron homeostasis is mediated by the fur repressor, which is highly conserved among various bacterial species. here we apply the comparative genomics approach to analyze candidate fur-binding sites in the genomes of escherichia coli (k12 and o157:h7), salmonella typhi, yersinia pestis and vibrio cholerae. we describe a number of new loci encoding siderophore biosynthesis and transport proteins. a new ... | 2001 | 11812853 |
| 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 |
| transfer rna-dependent amino acid biosynthesis: an essential route to asparagine formation. | biochemical experiments and genomic sequence analysis showed that deinococcus radiodurans and thermus thermophilus do not possess asparagine synthetase (encoded by asna or asnb), the enzyme forming asparagine from aspartate. instead these organisms derive asparagine from asparaginyl-trna, which is made from aspartate in the trna-dependent transamidation pathway [becker, h. d. & kern, d. (1998) proc. natl. acad. sci. usa 95, 12832-12837; and curnow, a. w., tumbula, d. l., pelaschier, j. t., min, ... | 2002 | 11880622 |
| firm but slippery attachment of deinococcus geothermalis. | bacterial biofilms impair the operation of many industrial processes. deinococcus geothermalis is efficient primary biofilm former in paper machine water, functioning as an adhesion platform for secondary biofilm bacteria. it produces thick biofilms on various abiotic surfaces, but the mechanism of attachment is not known. high-resolution field-emission scanning electron microscopy and atomic force microscopy (afm) showed peritrichous adhesion threads mediating the attachment of d. geothermalis ... | 2002 | 11948162 |
| 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 |
| taxis response of various denitrifying bacteria to nitrate and nitrite. | the taxis response of rhodobacter sphaeroides 2.4.1 and 2.4.3, rhodopseudomonas palustris, and agrobacterium tumefaciens to nitrate and nitrite was evaluated by observing the macroscopic behavior of cells suspended in soft agar and incubated under various conditions. r. sphaeroides 2.4.3, which is capable of both nitrate and nitrite reduction, showed a taxis response to both nitrate and nitrite. r. sphaeroides 2.4.1, which contains nitrate reductase but not nitrite reductase, did not show a taxi ... | 2002 | 11976082 |
| comparative evaluation of the bd phoenix and vitek 2 automated instruments for identification of isolates of the burkholderia cepacia complex. | we evaluated two new automated identification systems, the bd phoenix (becton dickinson) and the vitek 2 (biomérieux), for identification of isolates of the burkholderia cepacia complex (bcc). the test sample included 42 isolates of the highly virulent and epidemic genomovar iii, 45 isolates of b. multivorans, and 47 isolates of other members of the bcc. rates of correct identification by the bd phoenix and vitek 2 were similar when all bcc isolates were considered (50 and 53%, respectively) but ... | 2002 | 11980954 |
| probabilistic clustering of sequences: inferring new bacterial regulons by comparative genomics. | genome-wide comparisons between enteric bacteria yield large sets of conserved putative regulatory sites on a gene-by-gene basis that need to be clustered into regulons. using the assumption that regulatory sites can be represented as samples from weight matrices (wms), we derive a unique probability distribution for assignments of sites into clusters. our algorithm, "procse" (probabilistic clustering of sequences), uses monte carlo sampling of this distribution to partition and align thousands ... | 2002 | 12032281 |
| 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 |
| regulation of riboflavin biosynthesis and transport genes in bacteria by transcriptional and translational attenuation. | the riboflavin biosynthesis in bacteria was analyzed using comparative analysis of genes, operons and regulatory elements. a model for regulation based on formation of alternative rna structures involving the rfn elements is suggested. in gram-positive bacteria including actinomycetes, thermotoga, thermus and deinococcus, the riboflavin metabolism and transport genes are predicted to be regulated by transcriptional attenuation, whereas in most gram-negative bacteria, the riboflavin biosynthesis ... | 2002 | 12136096 |
| cluster ii che genes from pseudomonas aeruginosa are required for an optimal chemotactic response. | pseudomonas aeruginosa, a gamma-proteobacterium, is motile by means of a single polar flagellum and is chemotactic to a variety of organic compounds and phosphate. p. aeruginosa has multiple homologues of escherichia coli chemotaxis genes that are organized into five gene clusters. previously, it was demonstrated that genes in cluster i and cluster v are essential for chemotaxis. a third cluster (cluster ii) contains a complete set of che genes, as well as two genes, mcpa and mcpb, encoding meth ... | 2002 | 12142407 |
| 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 ... | 2002 | 12073132 |
| 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 |
| r391: a conjugative integrating mosaic comprised of phage, plasmid, and transposon elements. | the conjugative, chromosomally integrating element r391 is the archetype of the incj class of mobile genetic elements. originally found in a south african providencia rettgeri strain, r391 carries antibiotic and mercury resistance traits, as well as genes involved in mutagenic dna repair. while initially described as a plasmid, r391 has subsequently been shown to be integrated into the bacterial chromosome, employing a phage-like integration mechanism closely related to that of the sxt element f ... | 2002 | 12193633 |