| deletion of flavoredoxin gene in desulfovibrio gigas reveals its participation in thiosulfate reduction. | the gene encoding desulfovibrio gigas flavoredoxin was deleted to elucidate its physiological role in the sulfate metabolism. disruption of flr gene strongly inhibited the reduction of thiosulfate and exhibited a reduced growth in the presence of sulfite with lactate as electron donor. the growth with sulfate was not however affected by the lack of this protein. additionally, flr mutant cells revealed a decrease of about 50% in the h2 consumption rate using thiosulfate as electron acceptor. alto ... | 2005 | 16099456 |
| gene expression analysis of the mechanism of inhibition of desulfovibrio vulgaris hildenborough by nitrate-reducing, sulfide-oxidizing bacteria. | sulfate-reducing bacteria (srb) are inhibited by nitrate-reducing, sulfide-oxidizing bacteria (nr-sob) in the presence of nitrate. this inhibition has been attributed either to an increase in redox potential or to production of nitrite by the nr-sob. nitrite specifically inhibits the final step in the sulfate reduction pathway. when the nr-sob thiomicrospira sp. strain cvo was added to mid-log phase cultures of the srb desulfovibrio vulgaris hildenborough in the presence of nitrate, sulfate redu ... | 2005 | 16104868 |
| study of the spin-spin interactions between the metal centers of desulfovibrio gigas aldehyde oxidoreductase: identification of the reducible sites of the [2fe-2s]1+,2+ clusters. | the aldehyde oxidoreductase from desulfovibrio gigas belongs to the family of molybdenum hydroxylases. besides a molybdenum cofactor which constitutes their active site, these enzymes contain two [2fe-2s](2+,1+) clusters which are believed to transfer the electrons provided by the substrate to an acceptor which is either a fad group or an electron-transferring protein. when the three metal centers of d. gigas aor are simultaneously paramagnetic, splittings due to intercenter spin-spin interactio ... | 2005 | 16114900 |
| heat capacity-independent determination of differential free energy of stability between structurally homologous proteins. | under the assumption of equivalent heat capacity values, the differential free energy of stability for a pair of proteins midway between their thermal unfolding transition temperatures is shown to be independent of deltac(p) up to its cubic term in deltat(m). for model calculations reflecting the nearly 30 degrees c difference in t(m) for the adenylate kinases from the arctic bacterium bacillus globisporus and the thermophilic bacterium geobacillus stearothermophilus, the resultant error in esti ... | 2006 | 16125837 |
| characterisation of the 11 kb dna region adjacent to the gene encoding desulfovibrio gigas flavoredoxin. | flavoredoxin is an fmn binding protein that functions as an electron carrier in the sulphate metabolism of desulfovibrio gigas. the neighbouring dna regions of the gene encoding flavoredoxin were sequenced and characterised. transcript analysis of the flavoredoxin gene resulted in a positive band corresponding to the size of the coding region, suggesting that flavoredoxin is encoded by a monocystronic unit, as previously suggested by sequence analysis. analysis of the adjacent dna regions reveal ... | 2005 | 16147877 |
| identification of variant molecules of bacillus thermoproteolyticus ferredoxin: crystal structure reveals bound coenzyme a and an unexpected [3fe-4s] cluster associated with a canonical [4fe-4s] ligand motif. | during the purification of recombinant bacillus thermoproteolyticus ferredoxin (btfd) from escherichia coli, we have noted that some fe-s proteins were produced in relatively small amounts compared to the originally identified btfd carrying a [4fe-4s] cluster. these variants could be purified into three fe-s protein components (designated as v-i, v-ii, and v-iii) by standard chromatography procedures. uv-vis and epr spectroscopic analyses indicated that each of these variants accommodates a [3fe ... | 2005 | 16156653 |
| caseinoglycomacropeptide inhibits adhesion of pathogenic escherichia coli strains to human cells in culture. | caseinoglycomacropeptide (cgmp) derived from kappa-casein was investigated for its ability to inhibit the adhesion of 3 strains of verotoxigenic escherichia coli (vtec) and 3 strains of enteropathogenic escherichia coli (epec) to human ht29 tissue cell cultures. effects on adhesion of desulfovibrio desulfuricans, lactobacillus pentosus, lactobacillus casei, lactobacillus acidophilus, and lactobacillus gasseri were also investigated. generally, cgmp exerted effective anti-adhesive properties at a ... | 2005 | 16162518 |
| hydrogenases in desulfovibrio vulgaris hildenborough: structural and physiologic characterisation of the membrane-bound [nifese] hydrogenase. | the genome of desulfovibrio vulgaris hildenborough (dvh) encodes for six hydrogenases (hases), making it an interesting organism to study the role of these proteins in sulphate respiration. in this work we address the role of the [nifese] hase, found to be the major hase associated with the cytoplasmic membrane. the purified enzyme displays interesting catalytic properties, such as a very high h(2) production activity, which is dependent on the presence of phospholipids or detergent, and resista ... | 2005 | 16187073 |
| triple-resonance methods for complete resonance assignment of aromatic protons and directly bound heteronuclei in histidine and tryptophan residues. | a set of three experiments is described which correlate aromatic resonances of histidine and tryptophan residues with amide resonances in 13c/15n-labelled proteins. provided that backbone 1h and 15n positions of the sequentially following residues are known, this results in sequence-specific assignment of histidine 1h(delta2)/13c(delta2) and 1h(epsilon1)/13c(epsilon1) as well as tryptophan 1h(delta1)/13c(delta1), 1h(zeta2)/13c(zeta2), 1h(eta2)/13c(eta2), 1h(epsilon3)/13c(epsilon3), 1h(zeta3)/13c ... | 2005 | 16211484 |
| [determination of minimal concentrations of biocorrosion inhibitors by a bioluminescence method in relation to bacteria, participating in biocorrosion]. | by using a bioluminescence atp assay, we have determined the minimal concentrations of some biocorrosion inhibitors (katon, khazar, vfiks-82, nitro-1, kaspii-2, and kaspii-4) suppressing most common microbial corrosion agents: desulfovibrio desulfuricans, desulfovibrio vulgaris, pseudomonas putida, pseudomonas fluorescens, and acidithiobacillus ferrooxidans. the cell titers determined by the bioluminescence method, including not only dividing cells but also their dormant living counterparts, are ... | 2005 | 16212040 |
| [microbial community structure analyzed by single-strand conformation polymorphism technique in sulfate-reducing reactor]. | analyses of microbial community structure and the relationships between sulfate-reducing bacteria (srbs) and acidogenic bacteria (abs) in a completely stirred sulfate-reducing reactor were carried out by modified polymerase chain reaction-single-stranded conformation polymorphism (pcr-sscp) targeted eubacterial 16s ribosomal rna gene. a total of 13 bands were obtained and 6 of them (a1, a3, a4, a5, a9, a10) were sequenced. the sequences are similar to leuconostoc mesenteroides (genbank access no ... | 2005 | 16212191 |
| the type i/type ii cytochrome c3 complex: an electron transfer link in the hydrogen-sulfate reduction pathway. | in desulfovibrio metabolism, periplasmic hydrogen oxidation is coupled to cytoplasmic sulfate reduction via transmembrane electron transfer complexes. type ii tetraheme cytochrome c3 (tpii-c3), nine-heme cytochrome c (9hca) and 16-heme cytochrome c (hmca) are periplasmic proteins associated to these membrane-bound redox complexes and exhibit analogous physiological function. type i tetraheme cytochrome c3 (tpi-c3) is thought to act as a mediator for electron transfer from hydrogenase to these mu ... | 2005 | 16226767 |
| degradation of dibenzothiophene by sulfate-reducing bacteria cultured in the presence of only nitrogen gas. | to remove sulfur compounds in petroleum, we isolated sulfate-reducing bacteria that could degrade dibenzothiophene in the presence of only nitrogen gas. among the 19 strains isolated, some could grow in the presence of 10% (v/v) kerosene and of which two strains were identified as desulfomicrobium escambium and desulfovibrio longreachii. gas chromatography of the ethyl-acetate extract of bacterial cultures, in which 10% or more of the dibenzothiophene initially present was degraded, gave five un ... | 2001 | 16232954 |
| multi-heme cytochromes--new structures, new chemistry. | heme is one of the most pervasive cofactors in nature and the c-type cytochromes represent one of the largest families of heme-containing proteins. recent progress in bacterial genomic analysis has revealed a vast range of genes encoding novel c-type cytochromes that contain multiple numbers of heme cofactors. the genome sequence of geobacter sulfurreducens, for example, includes some one hundred genes encoding c-type cytochromes, with around seventy of these containing two, or more, heme groups ... | 2005 | 16234915 |
| geophysical imaging of stimulated microbial biomineralization. | understanding how microorganisms influence the physical and chemical properties of the subsurface is hindered by our inability to observe microbial dynamics in real time and with high spatial resolution. here, we investigate the use of noninvasive geophysical methods to monitor biomineralization at the laboratory scale during stimulated sulfate reduction under dynamic flow conditions. alterations in sediment characteristics resulting from microbe-mediated sulfide mineral precipitation were conco ... | 2005 | 16245832 |
| phospholipid-dependent regulation of cytochrome c3-mediated electron transport across membranes. | cytochrome c3 (cyt c3) can mediate electron transport across phosphatidylcholine (pc)/cardiolipin (cl) and pc/phosphatidylglycerol (pg) membranes. a two-molecule process is involved in the electron transport across pc/cl membranes in the liquid-crystalline state. in contrast, a single-molecule process dominates the electron transport across pc/cl membranes in the gel state and pc/pg membranes in the liquid-crystalline and gel states. namely, the electron transport mechanism differs with the phos ... | 2006 | 16258050 |
| desulfovibrionales-related bacteria in a paper mill environment as detected with molecular techniques and culture. | the aim of the present study was to evaluate the suitability of a nested pcr-dgge (denaturing gradient gel electrophoresis) method for the detection of desulfovibrionales-related sulfate-reducing bacteria (srb) from paper mill samples. the samples were also analyzed with culturing. srb cause/enhance industrial problems, namely creation of foul-smelling gases (hydrogen sulfide) and biological corrosion, and so far there has not been a simple method to study these bacteria in paper mill laboratori ... | 2006 | 16261358 |
| a method adapting microarray technology for signature-tagged mutagenesis of desulfovibrio desulfuricans g20 and shewanella oneidensis mr-1 in anaerobic sediment survival experiments. | signature-tagged mutagenesis (stm) is a powerful technique that can be used to identify genes expressed by bacteria during exposure to conditions in their natural environments. to date, there have been no reports of studies in which this approach was used to study organisms of environmental, rather than pathogenic, significance. we used a mini-tn10 transposon-bearing plasmid, pbsl180, that efficiently and randomly mutagenized desulfovibrio desulfuricans g20 in addition to shewanella oneidensis m ... | 2005 | 16269742 |
| activation process of [nife] hydrogenase elucidated by high-resolution x-ray analyses: conversion of the ready to the unready state. | hydrogenases catalyze oxidoreduction of molecular hydrogen and have potential applications for utilizing dihydrogen as an energy source. [nife] hydrogenase has two different oxidized states, ni-a (unready, exhibits a lag phase in reductive activation) and ni-b (ready). we have succeeded in converting ni-b to ni-a with the use of na2s and o2 and determining the high-resolution crystal structures of both states. ni-b possesses a monatomic nonprotein bridging ligand at the ni-fe active site, wherea ... | 2005 | 16271886 |
| role of the tetrahemic subunit in desulfovibrio vulgaris hildenborough formate dehydrogenase. | in the anaerobic sulfate-reducing bacterium desulfovibrio vulgaris hildenborough (dvh), the genome sequencing revealed the presence of three operons encoding formate dehydrogenases. fdh1 encodes an alphabetagamma trimeric enzyme containing 11 heme binding sites; fdh2 corresponds to an alphabetagamma trimeric enzyme with a tetrahemic subunit; fdh3 encodes an alphabeta dimeric enzyme. in the present work, spectroscopic measurements demonstrated that the reduction of cytochrome c(553) was obtained ... | 2005 | 16274230 |
| biophysical properties of a c-type heme in chemotaxis signal transducer protein dcra. | chemotaxis signal transducer protein dcra from a sulfate-reducing bacterium desulfovibrio vulgaris hildenborough was previously shown to contain a c-type heme in its periplasmic domain (dcra-n) for sensing redox and/or oxygen [fu et al. (1994) j. bacteriol. 176, 344-350], which is the first example of a heme-based sensor protein containing a c-type heme as a prosthetic group. optical absorption and resonance raman spectroscopies indicates that heme c in dcra-n shows a redox-dependent ligand exch ... | 2005 | 16285745 |
| oriented immobilization of desulfovibrio gigas hydrogenase onto carbon electrodes by covalent bonds for nonmediated oxidation of h2. | the orientation of hydrogenase bound covalently to a pyrolytic graphite edge electrode modified with a 4-aminophenyl monolayer can be modulated via electrostatic interactions during the immobilization step. at low ionic strength and when the amino groups of the electrode surface are mostly protonated, the hydrogenase is immobilized with the negatively charged region that surrounds its 4fe4s cluster nearer to the protein surface facing the electrode. this allows direct electron transfer between t ... | 2005 | 16287271 |
| biochemical and spectroscopic characterization of an aldehyde oxidoreductase isolated from desulfovibrio aminophilus. | aldehyde oxidoreductase (aor) activity has been found in a number of sulfate-reducing bacteria. the enzyme that is responsible for the conversion of aldehydes to carboxylic acids is a mononuclear molybdenum enzyme belonging to the xanthine oxidase family. we report here the purification and characterization of aor isolated from the sulfate-reducing bacterium desulfovibrio (d.) aminophilus dsm 12254, an aminolytic strain performing thiosulfate dismutation. the enzyme is a homodimer (ca. 200 kda), ... | 2006 | 16290059 |
| the influence of nickel on the adhesion ability of desulfovibrio desulfuricans. | the build-up of biofilms on metals surfaces may lead to severe corrosion, especially in the presence of sulphate-reducing bacteria (srb). to prevent the deterioration of material caused by biofilms it is necessary to understand the processes governing biofilm development including mechanisms of cell adhesion. additionally, corrosion of metallic surfaces due to bacteria may lead to the dissolution of metallic elements that may further affect adhesion and biofilm development. a study was carried o ... | 2005 | 16290113 |
| changes in bacterial community structure correlate with initial operating conditions of a field-scale denitrifying fluidized bed reactor. | high levels of nitrate are present in groundwater migrating from the former waste disposal ponds at the y-12 national security complex in oak ridge, tn. a field-scale denitrifying fluidized bed reactor (fbr) was designed, constructed, and operated with ethanol as an electron donor for the removal of nitrate. after inoculation, biofilms developed on the granular activated carbon particles. changes in the bacterial community of the fbr were evaluated with clone libraries (n = 500 partial sequences ... | 2006 | 16292532 |
| a single-crystal endor and density functional theory study of the oxidized states of the [nife] hydrogenase from desulfovibrio vulgaris miyazaki f. | the catalytic center of the [nife] hydrogenase of desulfovibrio vulgaris miyazaki f in the oxidized states was investigated by electron paramagnetic resonance and electron-nuclear double resonance spectroscopy applied to single crystals of the enzyme. the experimental results were compared with density functional theory (dft) calculations. for the ni-b state, three hyperfine tensors could be determined. two tensors have large isotropic hyperfine coupling constants and are assigned to the beta-ch ... | 2006 | 16292669 |
| phylogenetic analysis of tce-dechlorinating consortia enriched on a variety of electron donors. | two rapidly fermented electron donors, lactate and methanol, and two slowly fermented electron donors, propionate and butyrate, were selected for enrichment studies to evaluate the characteristics of anaerobic microbial consortia that reductively dechlorinate tce to ethene. each electron donor enrichment subculture demonstrated the ability to dechlorinate tce to ethene through several serial transfers. microbial community analyses based upon 16s rdna, including terminal restriction fragment leng ... | 2005 | 16294874 |
| correlation between mrna and protein abundance in desulfovibrio vulgaris: a multiple regression to identify sources of variations. | parallel profiling of mrna and protein on a global scale and integrative analysis of these two data types could provide additional insights into the metabolic mechanisms underlying complex biological systems. however, because mrna and protein abundance are affected by many cellular and physical processes, there have been conflicting results on their correlation. using whole-genome microarray and lc-ms/ms proteomic data collected from desulfovibrio vulgaris grown under three different conditions, ... | 2006 | 16310166 |
| the active site of the [fefe]-hydrogenase from desulfovibrio desulfuricans. ii. redox properties, light sensitivity and co-ligand exchange as observed by infrared spectroscopy. | in [fefe]-hydrogenases, the h cluster (hydrogen-activating cluster) contains a di-iron centre ([2fe]h subcluster, a (l)(co)(cn)fe(mu-rs2)(mu-co)fe(cyss)(co)(cn) group) covalently attached to a cubane iron-sulphur cluster ([4fe-4s]h subcluster). the cys-thiol functions as the link between one iron (called fe1) of the [2fe]h subcluster and one iron of the cubane subcluster. the other iron in the [2fe]h subcluster is called fe2. the light sensitivity of the desulfovibrio desulfuricans enzyme in a v ... | 2006 | 16323019 |
| the active site of the [fefe]-hydrogenase from desulfovibrio desulfuricans. i. light sensitivity and magnetic hyperfine interactions as observed by electron paramagnetic resonance. | the hydrogen-activating cluster (h cluster) in [fefe]-hydrogenases consists of two moieties. the [2fe]h subcluster is a (l)(co)(cn)fe(mu-rs2)(mu-co)fe(cyss)(co)(cn) centre. the cys-bound fe is called fe1, the other iron fe2. the cys-thiol forms a bridge to a [4fe-4s] cluster, the [4fe-4s]h subcluster. we report that electron paramagnetic resonance (epr) spectra of the 57fe-enriched enzyme from desulfovibrio desulfuricans in the h(ox)-co state are consistent with a magnetic hyperfine interaction ... | 2006 | 16323020 |
| effects of oxygen exposure on respiratory activities of desulfovibrio desulfuricans strain dvo1 isolated from activated sludge. | the present study addresses the effects of oxygen exposure on the aerobic and anaerobic respiratory activity of desulfovibrio desulfuricans strain dvo1. this strain was isolated from the highest sulfate-reduction positive most-probable-number dilution (10(6)) of an activated sludge sample, which had been subjected to 120 h of continuous aeration. washed cell suspensions of strain dvo1 were aerated at 50% atmospheric oxygen saturation in sulfide-free media for a period of 33 h in the presence or ... | 2005 | 16329947 |
| characterisation of intestinal bacteria in infant stools using real-time pcr and northern hybridisation analyses. | real-time pcr and northern hybridisations were used to quantify bacterial populations in the large gut of infants. pcr primers for rapid, sensitive, high throughput detection of bifidobacteria, bacteroides, sulphate-reducing bacteria and enterococcus faecalis, based on analysis of 16s rrna genes were used. bacterial populations were analysed in faeces from 40 infants aged 0-6, 7-12 and 13-24 months. the effects of breast versus bottle feeding was also investigated. real-time pcr indicated that b ... | 2005 | 16329974 |
| resonance raman fingerprinting of multiheme cytochromes from the cytochrome c3 family. | resonance raman (rr) spectroscopy was used to investigate conformational characteristics of the hemes of several ferricytochromes of the cytochrome c3 family, electron transfer proteins isolated from the periplasm and membranes of sulfate-reducing bacteria. our analysis concentrated on the low-frequency region of the rr spectra, a fingerprint region that includes vibrations for heme-protein c-s bonds [nu(c(a)s)]. it has been proposed that these bonds are directly involved in the electron transfe ... | 2006 | 16341896 |
| sulfide production from cysteine by desulfovibrio desulfuricans. | two rumen nitrate-reducing isolates of desulfovibrio desulfuricans were found to hydrolyze cysteine with the production of sulfide and pyruvate. when cultured on agar medium containing yeast extract with nitrate as the primary electron acceptor and ferrous chloride as the indicator, blackening of colonies occurred. the blackening of colonies appeared sooner and was more intense when either cysteine or sulfate was added to the culture medium with nitrate present. | 1980 | 16345519 |
| enumeration and relative importance of acetylene-reducing (nitrogen-fixing) bacteria in a delaware salt marsh. | three groups of n(2)-fixing bacteria were enumerated from the top 1 cm of the surface in four vegetational areas in a delaware salt marsh. the results over the 9-month sampling period showed that there were no discernible seasonal patterns for any of the groups enumerated (azotobacter sp., clostridium sp., and desulfovibrio sp.). azotobacter sp. was present in numbers of 10 per g of dry mud, whereas the two anaerobic fixers were present in much lower numbers (10 to 10 per g of dry mud). there we ... | 1980 | 16345564 |
| propionate-degrading bacterium, syntrophobacter wolinii sp. nov. gen. nov., from methanogenic ecosystems. | a new genus and species of a nonmotile gram-negative rod, syntrophobacter wolinii, is the first bacterium described which degrades propionate only in coculture with an h(2)-using organism and in the absence of light or exogenous electron acceptors such as o(2), sulfate, or nitrate. it was isolated from methanogenic enrichments from an anaerobic municipal sewage digestor, using anaerobic roll tubes containing a medium with propionate as the energy source in association with an h(2)-using, sulfate ... | 1980 | 16345640 |
| anaerobic degradation of lactate by syntrophic associations of methanosarcina barkeri and desulfovibrio species and effect of h(2) on acetate degradation. | when grown in the absence of added sulfate, cocultures of desulfovibrio desulfuricans or desulfovibrio vulgaris with methanobrevibacter smithii (methanobacterium ruminantium), which uses h(2) and co(2) for methanogenesis, degraded lactate, with the production of acetate and ch(4). when d. desulfuricans or d. vulgaris was grown in the absence of added sulfate in coculture with methanosarcina barkeri (type strain), which uses both h(2)-co(2) and acetate for methanogenesis, lactate was stoichiometr ... | 1981 | 16345708 |
| syntrophomonas wolfei gen. nov. sp. nov., an anaerobic, syntrophic, fatty acid-oxidizing bacterium. | an anaerobic, nonphototrophic bacterium that beta-oxidizes saturated fatty acids (butyrate through octanoate) to acetate or acetate and propionate using protons as the electron acceptor (h(2) as electron sink product) was isolated in coculture with either a non-fatty acid-degrading, h(2)-utilizing desulfovibrio sp. or methanogens. three strains of the bacterium were characterized and are described as a new genus and species, syntrophomonas wolfei. s. wolfei is a gram-negative, slightly helical r ... | 1981 | 16345745 |
| conversion of cellulose to methane and carbon dioxide by triculture of acetivibrio cellulolyticus, desulfovibrio sp., and methanosarcina barkeri. | the fermentation of cellulose by monocultures of acetivibrio cellulolyticus and cocultures of a. cellulolyticus-methanosarcina barkeri, a. cellulolyticus-desulfovibrio sp., and a. cellulolyticus-m. barkeri-desulfovibrio sp. was studied. the monoculture produced ethanol, acetate, h(2), and co(2). more acetate and less ethanol was formed by the cocultures than by the monoculture. acetate was utilized by m. barkeri in coculture with a. cellulolyticus after a lag period, whereas ethanol was metaboli ... | 1981 | 16345841 |
| assimilatory sulfur metabolism in marine microorganisms: considerations for the application of sulfate incorporation into protein as a measurement of natural population protein synthesis. | the sulfur content of residue protein was determined for pure cultures of nitrosococcus oceanus, desulfovibrio salexigens, 4 mixed populations of fermentative bacteria, 22 samples from mixed natural population enrichments, and 11 nutritionally and morphologically distinct isolates from enrichments of sargasso sea water. the average 1.09 +/- 0.14% (by weight) s in protein for 13 pure cultures agrees with the 1.1% calculated from average protein composition. an operational value encompassing all m ... | 1982 | 16345919 |
| influence of acetylene on growth of sulfate-respiring bacteria. | at a concentration of 20% of the atmosphere of the culture flasks, acetylene inhibited growth and carbon dioxide production by desulfovibrio desulfuricans and desulfovibrio gigas. the bacteria did not reduce acetylene to ethylene, and neither acetylene dicarboxylic acid nor ethylene was inhibitory. at 10%, acetylene was partially inhibitory for the desulfovibrios. at 5%, acetylene impeded the rate but did not limit the extent of growth and catabolism of the desulfovibrios. desulfotomaculum rumin ... | 1982 | 16345981 |
| methanogenesis from choline by a coculture of desulfovibrio sp. and methanosarcina barkeri. | a sulfate-reducing vibrio was isolated from a methanogenic enrichment with choline as the sole added organic substrate. this organism was identified as a member of the genus desulfovibrio and was designated desulfovibrio strain g1. in a defined medium devoid of sulfate, a pure culture of desulfovibrio strain g1 fermented choline to trimethylamine, acetate, and ethanol. in the presence of sulfate, more acetate and less ethanol were formed from choline than in the absence of sulfate. when grown in ... | 1983 | 16346162 |
| radioassay for hydrogenase activity in viable cells and documentation of aerobic hydrogen-consuming bacteria living in extreme environments. | an isotopic tracer assay based on the hydrogenase-dependent formation of tritiated water from tritium gas was developed for in life analysis of microbial hydrogen transformation. this method allowed detection of bacterial hydrogen metabolism in pure cultures or in natural samples obtained from aquatic ecosystems. a differentiation between chemical-biological and aerobic-anaerobic hydrogen metabolism was established by variation of the experimental incubation temperature or by addition of selecti ... | 1983 | 16346288 |
| energetics of growth of a defined mixed culture of desulfovibrio vulgaris and methanosarcina barkeri: interspecies hydrogen transfer in batch and continuous cultures. | interspecies hydrogen transfer was studied in desulfovibrio vulgaris-methanosarcina barkeri mixed cultures. experiments were performed under batch and continuous growth culture conditions. lactate or pyruvate was used as an energy source. in batch culture and after 30 days of simultaneous incubation, these organisms were found to yield 1.5 mol of methane and 1.5 mol of carbon dioxide per mol of lactate fermented. when m. barkeri served as the hydrogen acceptor, growth yields of d. vulgaris were ... | 1983 | 16346421 |
| growth of a strictly anaerobic bacterium on furfural (2-furaldehyde). | a strictly anaerobic bacterium was isolated from a continuous fermentor culture which converted the organic constituents of sulfite evaporator condensate to methane and carbon dioxide. furfural is one of the major components of this condensate. this furfural isolate could degrade furfural as the sole source of carbon and energy in a defined mineral-vitamin-sulfate medium. acetic acid was the major fermentation product. this organism could also use ethanol, lactate, pyruvate, or fumarate and cont ... | 1983 | 16346423 |
| methanogenesis from sucrose by defined immobilized consortia. | a bacterial consortium capable of sucrose degradation primarily to ch(4) and co(2) was constructed, with acetate as the key methanogenic precursor. in addition, the effect of agar immobilization on the activity of the consortium was determined. the primary fermentative organism, escherichia coli, produced acetate, formate, h(2), and co(2) (known substrates for methanogens), as well as ethanol and lactate, compounds that are not substrates for methanogens. oxidation of the nonmethanogenic substra ... | 1984 | 16346452 |
| competition for sulfate and ethanol among desulfobacter, desulfobulbus, and desulfovibrio species isolated from intertidal sediments. | competition for sulfate and ethanol among desulfobacter, desulfobulbus, and desulfovibrio species isolated from estuarine sediments was studied in energy-limited chemostats. desulfovibrio baculatus was the most successful competitor for limiting amounts of sulfate and ethanol, followed by desulfobulbus propionicus. the success of desulfovibrio baculatus was dependent on the availability of sufficient iron. of the three species studied, desulfobacter postgatei was the least successful competitor ... | 1984 | 16346474 |
| isolation and partial characterization of bacteria in an anaerobic consortium that mineralizes 3-chlorobenzoic acid. | a methanogenic consortium able to use 3-chlorobenzoic acid as its sole energy and carbon source was enriched from anaerobic sewage sludge. seven bacteria were isolated from the consortium in mono- or coculture. they included: one dechlorinating bacterium (strain dcb-1), one benzoate-oxidizing bacterium (strain bz-2), two butyrate-oxidizing bacteria (strains sf-1 and nsf-2), two h(2)-consuming methanogens (methanospirillum hungatei pm-1 and methanobacterium sp. strain pm-2), and a sulfate-reducin ... | 1984 | 16346648 |
| biochemical and immunological study of cell envelope proteins in sulfate-reducing bacteria. | the envelope proteins of 5 strains of the genus desulfotomaculum and 12 strains of the genus desulfovibrio were studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. the desulfovibrio strains exhibited a typical gram-negative cell envelope, whereas the cell envelope of desulfotomaculum strains appeared to be gram-positive. a close relationship between strains of desulfotomaculum nigrificans was observed. a comparison between different species of desulfotomaculu ... | 1985 | 16346839 |
| sulfate-reducing bacteria: principal methylators of mercury in anoxic estuarine sediment. | substrate-electron acceptor combinations and specific metabolic inhibitors were applied to anoxic saltmarsh sediment spiked with mercuric ions (hg) in an effort to identify, by a direct approach, the microorganisms responsible for the synthesis of hazardous monomethylmercury. 2-bromoethane sulfonate (30 mm), a specific inhibitor of methanogens, increased monomethylmercury synthesis, whereas sodium molybdate (20 mm), a specific inhibitor of sulfate reducers, decreased hg methylation by more than ... | 1985 | 16346866 |
| sulfate-dependent interspecies h(2) transfer between methanosarcina barkeri and desulfovibrio vulgaris during coculture metabolism of acetate or methanol. | we compared the metabolism of methanol and acetate when methanosarcina barkeri was grown in the presence and absence of desulfovibrio vulgaris. the sulfate reducer was not able to utilize methanol or acetate as the electron donor for energy metabolism in pure culture, but was able to grow in coculture. pure cultures of m. barkeri produced up to 10 mumol of h(2) per liter in the culture headspace during growth on acetate or methanol. in coculture with d. vulgaris, the gaseous h(2) concentration w ... | 1985 | 16346878 |
| effect of fall turnover on terminal carbon metabolism in lake mendota sediments. | the carbon and electron flow pathways and the bacterial populations responsible for the transformation of h(2)-co(2), formate, methanol, methylamine, acetate, ethanol, and lactate were examined in eutrophic sediments collected during summer stratification and fall turnover. the rate of methane formation averaged 1,130 mumol of ch(4) per liter of sediment per day during late-summer stratification versus 433 mumol of ch(4) per liter of sediment per day during the early portion of fall turnover, wh ... | 1985 | 16346933 |
| microbial ecophysiology of whey biomethanation: characterization of bacterial trophic populations and prevalent species in continuous culture. | the organization and species composition of bacterial trophic groups associated with lactose biomethanation were investigated in a whey-processing chemostat by enumeration, isolation, and general characterization studies. the bacteria were spatially organized as free-living forms and as self-immobilized forms appearing in flocs. three dominant bacterial trophic group populations were present (in most probable number per milliliter) whose species numbers varied with the substrate consumed: hydrol ... | 1986 | 16346970 |
| methane production from formate by syntrophic association of methanobacterium bryantii and desulfovibrio vulgaris jj. | coculture of a sulfate-reducing bacterium, when grown in the absence of added sulfate, with methanobacterium bryantii, which uses only h(2) and co(2) for methanogenesis, degraded formate to ch(4). a pure culture of desulfovibrio vulgaris jj was able to produce small amounts of h(2). such a syntrophic relationship might provide an additional way to avoid formate accumulation in anaerobic environments. | 1986 | 16347251 |
| effects of hydrogen pressure during growth and effects of pregrowth with hydrogen on acetate degradation by methanosarcina species. | methanosarcina barkeri 227 and methanosarcina mazei s-6 grew with acetate as the substrate; we found little effect of h(2) on the rate of aceticlastic growth in the presence of various h(2) pressures between 2 and 810 pa. we used physical (h(2) addition or flushing the headspace to remove h(2)) and biological (h(2)-producing or -utilizing bacteria in cocultures) methods for controlling h(2) pressure in methanosarcina cultures growing on acetate. added h(2) (ca. 100 pa) was removed rapidly (a few ... | 1987 | 16347269 |
| effect of salinity on mercury-methylating activity of sulfate-reducing bacteria in estuarine sediments. | the biomethylation of mercury was measured in anoxic estuarine sediments that ranged in salinity from 0.03 to 2.4% with or without added molybdate, an inhibitor of sulfate reducers. mercury methylation was inhibited by molybdate by more than 95%, regardless of sediment salinity. in the absence of inhibitor, high-salinity sediments methylated mercury at only 40% of the level observed in low-salinity sediments. in response to molybdate inhibition of sulfate reducers, methanogenesis increased up to ... | 1987 | 16347274 |
| properties of desulfovibrio carbinolicus sp. nov. and other sulfate-reducing bacteria isolated from an anaerobic-purification plant. | several sulfate-reducing microorganisms were isolated from an anaerobic-purification plant. four strains were classified as desulfovibrio desulfuricans, desulfovibrio sapovorans, desulfobulbus propionicus, and desulfovibrio sp. the d. sapovorans strain contained poly-beta-hydroxybutyrate granules and seemed to form extracellular vesicles. a fifth isolate, desulfovibrio sp. strain edk82, was a gram-negative, non-spore-forming, nonmotile, curved organism. it was able to oxidize several substrates, ... | 1987 | 16347324 |
| microbial ecophysiology of whey biomethanation: comparison of carbon transformation parameters, species composition, and starter culture performance in continuous culture. | changes in lactose concentration and feed rate altered bacterial growth and population levels in a whey-processing chemostat. the bacterial population and methane production levels increased in relation to increased lactose concentrations comparable to those in raw whey (6%) and converted over 96% of the substrate to methane, carbon dioxide, and cells. sequential increases in the chemostat dilution rate demonstrated excellent biomethanation performance at retention times as low as 25 h. retentio ... | 1987 | 16347341 |
| reduction of selenate to selenide by sulfate-respiring bacteria: experiments with cell suspensions and estuarine sediments. | washed cell suspensions of desulfovibrio desulfuricans subsp. aestuarii were capable of reducing nanomolar levels of selenate to selenide as well as sulfate to sulfide. reduction of these species was inhibited by 1 mm selenate or tungstate. the addition of 1 mm sulfate decreased the reduction of selenate and enhanced the reduction of sulfate. increasing concentrations of sulfate inhibited rates of selenate reduction but enhanced sulfate reduction rates. cell suspensions kept in 1 mm selenate wer ... | 1987 | 16347366 |
| control of interspecies electron flow during anaerobic digestion: role of floc formation in syntrophic methanogenesis. | the flora of an anaerobic whey-processing chemostat was separated by anaerobic sedimentation techniques into a free-living bacterial fraction and a bacterial floc fraction. the floc fraction constituted a major part (i.e., 57% total protein) of the total microbial population in the digestor, and it accounted for 87% of the total co(2)-dependent methanogenic activity and 76% of the total ethanol-consuming acetogenic activity. lactose was degraded by both cellular fractions, but in the free flora ... | 1988 | 16347517 |
| control of interspecies electron flow during anaerobic digestion: significance of formate transfer versus hydrogen transfer during syntrophic methanogenesis in flocs. | microbial formate production and consumption during syntrophic conversion of ethanol or lactate to methane was examined in purified flocs and digestor contents obtained from a whey-processing digestor. formate production by digestor contents or purified digestor flocs was dependent on co(2) and either ethanol or lactate but not h(2) gas as an electron donor. during syntrophic methanogenesis, flocs were the primary site for formate production via ethanol-dependent co(2) reduction, with a formate ... | 1988 | 16347526 |
| effect of phosphate on the corrosion of carbon steel and on the composition of corrosion products in two-stage continuous cultures of desulfovibrio desulfuricans. | a field isolate of desulfovibrio desulfuricans was grown in defined medium in a two-stage continuous culture apparatus with different concentrations of phosphate in the feed medium. the first state (v1) was operated as a conventional chemostat (d = 0.045 h) that was limited in energy source (lactate) or phosphate. the second stage (v2) received effluent from v1 but no additional nutrients, and contained a healthy population of transiently starved or resting cells. an increase in the concentratio ... | 1988 | 16347552 |
| bioenergetic conditions of butyrate metabolism by a syntrophic, anaerobic bacterium in coculture with hydrogen-oxidizing methanogenic and sulfidogenic bacteria. | the butyrate-oxidizing, proton-reducing, obligately anaerobic bacterium nsf-2 was grown in batch cocultures with either the hydrogen-oxidizing bacterium methanospirillum hungatei pm-1 or desulfovibrio sp. strain ps-1. metabolism of butyrate occurred in two phases. the first phase exhibited exponential growth kinetics (phase a) and had a doubling time of 10 h. this value was independent of whether nsf-2 was cultured with a methanogen or a sulfate reducer and likely represents the maximum specific ... | 1988 | 16347645 |
| phospholipid fatty acid composition of the syntrophic anaerobic bacterium syntrophomonas wolfei. | the membrane phospholipid fatty acids (plfas) from several cocultures and a pure culture of syntrophomonas wolfei were determined by capillary column gas chromatography. cocultures of s. wolfei with a desulfovibrio sp. contained plfas from both organisms, whereas plfas from a coculture with methanospirillum hungatei contained very little biomass to analyze. the pure culture of s. wolfei grown on crotonate provided the best material for analysis of the plfas. the predominant plfas of s. wolfei we ... | 1988 | 16347667 |
| effect of calcium cation on plating efficiency of the sulfate-reducing bacterium desulfovibrio vulgaris. | the presence of ca (concentration, ca. 0.4 mm) in the growth medium causes cells of desulfovibrio vulgaris (hildenborough) to aggregate, leading to a decrease in plating efficiency. when the ca concentration in the medium was reduced 20-fold, cell aggregation did not occur and the plating efficiency increased from an initial value of 34% to a final value of 56%. | 1988 | 16347744 |
| methanogenesis from ethanol by defined mixed continuous cultures. | methanogenesis from ethanol by defined mixed continuous cultures was studied. under sulfate-free conditions, a desulfovibrio strain was used as the ethanol-degrading species producing acetic acid and hydrogen. in a two-membered mutualistic coculture, the hydrogen was converted to methane by a methanobacterium sp. and ph was maintained at neutrality by the addition of alkali. introduction of a third species, the acetate-utilizing methanosarcina mazei, obviated the need for external ph control. me ... | 1989 | 16347852 |
| isolation and characterization of a bacteriophage lytic for desulfovibrio salexigens, a salt-requiring, sulfate-reducing bacterium. | a bacteriophage that lysed desulfovibrio salexigens cells was isolated from marine sediments and preliminarily characterized by electron microscopy and electrophoretic analysis of structural proteins and genomic nucleic acid. the bacteriophage had an icosahedral head and a long flexible tail, and the buoyant density of the bacteriophage particles was 1.468 g/ml in cesium chloride. the particles consisted of a double-stranded dna molecule about 33 kilobase pairs long and at least 11 structural pr ... | 1989 | 16347872 |
| modification of lignins by growing cells of the sulfate-reducing anaerobe desulfovibrio desulfuricans. | the anaerobic sulfate-reducing bacterium desulfovibrio desulfuricans was grown on medium supplemented with either kraft lignin or lignosulfonate. only lignosulfonate contributed to the growth of d. desulfuricans cells, by replacing sulfate, a natural electron acceptor for this microorganism. kraft lignin added to the culture medium could not substitute for lactate or sulfate, both necessary culture medium components. however, it was found to enhance the viability of d. desulfuricans cells. when ... | 1989 | 16348007 |
| carbon flow in mercury biomethylation by desulfovibrio desulfuricans. | radiocarbon incorporation from pyruvate and serine into monomethylmercury by desulfovibrio desulfuricans was consistent with the proposal that the methyl group originates from c-3 of serine. immunodiagnostic assays measured 4 to 35 mug of tetrahydrofolate and 58 to 161 ng of cobalamin or a closely related cobalt porphyrin per g of cell protein in d. desulfuricans. the light-reversible inhibition of mercury methylation by propyl iodide in d. desulfuricans indicates methyl transfer by a cobalt por ... | 1990 | 16348104 |
| quantitative microbiological analysis of bacterial community shifts in a high-rate anaerobic bioreactor treating sulfite evaporator condensate. | the bacterial population of a high-rate, anaerobic, fixed-bed loop reactor treating sulfite evaporator condensate from the pulp industry was studied over a 14-month period. this period was divided into seven cycles that included a startup at the beginning of each cycle. some 82% of the total biomass was immobilized on and between the porous glass rings filling the reactor. the range of the total number of microorganisms in these biofilms was 2 x 10 to 7 x 10 cells per ml. enumeration and charact ... | 1990 | 16348253 |
| distribution of hydrogenase genes in desulfovibrio spp. and their use in identification of species from the oil field environment. | the distribution of genes for [fe], [nife], and [nifese] hydrogenases was determined for 22 desulfovibrio species. the genes for [nife] hydrogenase were present in all species, whereas those for the [fe] and [nifese] hydrogenases had a more limited distribution. sulfate-reducing bacteria from 16s rrna groups other than the genus desulfovibrio (r. devereux, m. delaney, f. widdel, and d. a. stahl, j. bacteriol. 171:6689-6695, 1989) did not react with the [nife] hydrogenase gene probe, which could ... | 1990 | 16348376 |
| methylmercury decomposition in sediments and bacterial cultures: involvement of methanogens and sulfate reducers in oxidative demethylation. | demethylation of monomethylmercury in freshwater and estuarine sediments and in bacterial cultures was investigated with ch(3)hgi. under anaerobiosis, results with inhibitors indicated partial involvement of both sulfate reducers and methanogens, the former dominating estuarine sediments, while both were active in freshwaters. aerobes were the most significant demethylators in estuarine sediments, but were unimportant in freshwater sediments. products of anaerobic demethylation were mainly co(2) ... | 1991 | 16348388 |
| immunological cross-reactivities of adenosine-5'-phosphosulfate reductases from sulfate-reducing and sulfide-oxidizing bacteria. | crude extracts from 14 species of sulfate-reducing bacteria comprising the genera desulfovibrio, desulfotomaculum, desulfobulbus, and desulfosarcina and from three species of sulfide-oxidizing bacteria were tested in an enzyme-linked immunosorbent assay with polyclonal antisera to adenosine 5'-phosphosulfate reductase from desulfovibrio desulfuricans g100a. the results showed that extracts from desulfovibrio species were all highly cross-reactive, whereas extracts from the other sulfate-reducing ... | 1991 | 16348440 |
| regulation of the periplasmic [fe] hydrogenase by ferrous iron in desulfovibrio vulgaris (hildenborough). | the periplasmic [fe] hydrogenase from the sulfate-reducing bacterium desulfovibrio vulgaris (hildenborough) dsm 8303 was found to be regulated by ferrous iron availability. during growth with 5 ppm of iron, the enzyme derepressed and the specific activity increased approximately fourfold, whereas the presence of 100 ppm of ferrous iron repressed the enzyme. the repression-derepression phenomenon with ferrous iron was found to be operative when the cells were cultured under either hydrogen or nit ... | 1993 | 16348873 |
| growth of syntrophic propionate-oxidizing bacteria with fumarate in the absence of methanogenic bacteria. | oxidation of succinate to fumarate is an energetically difficult step in the biochemical pathway of propionate oxidation by syntrophic methanogenic cultures. therefore, the effect of fumarate on propionate oxidation by two different propionate-oxidizing cultures was investigated. when the methanogens in a newly enriched propionate-oxidizing methanogenic culture were inhibited by bromoethanesulfonate, fumarate could act as an apparent terminal electron acceptor in propionate oxidation. c-nuclear ... | 1993 | 16348912 |
| methylmercury resistance in desulfovibrio desulfuricans strains in relation to methylmercury degradation. | two strains of desulfovibrio desulfuricans, one known to synthesize monomethylmercury from ionic mercury, were grown to determine methylmercury toxicity and for comparison with an anaerobic strain of clostridium pasteurianum, a h(2) producer, and with the broad-spectrum mercury-resistant pseudomonas putida strain fb-1, capable of degrading 1 mug of methylmercury to methane and elemental mercury in 2 h. the ch(3)hgcl resistance of d. desulfuricans strains was 10 times that of p. putida fb-1 and 1 ... | 1993 | 16349013 |
| nitrate reduction in a sulfate-reducing bacterium, desulfovibrio desulfuricans, isolated from rice paddy soil: sulfide inhibition, kinetics, and regulation. | from the second-highest dilution in a most-probable-number dilution series with lactate and sulfate as substrates and rice paddy soil as the inoculum, a strain of desulfovibrio desulfuricans was isolated. in addition to reducing sulfate, sulfite, and thiosulfate, the strain also reduced nitrate to ammonia. the latter process was studied in detail, since the ability to reduce nitrate was strongly influenced by the presence of sulfide. sulfide inhibited both growth on nitrate and nitrate reduction ... | 1994 | 16349159 |
| reduction of chromate by desulfovibrio vulgaris and its c(3) cytochrome. | washed cell suspensions of desulfovibrio vulgaris rapidly reduced cr(vi) to cr(iii) with h(2) as the electron donor. the c(3) cytochrome from this organism functioned as a cr(vi) reductase. d. vulgaris may have advantages over previously described cr(vi) reducers for the bioremediation of cr(vi)-contaminated waters. | 1994 | 16349200 |
| novel processes for anaerobic sulfate production from elemental sulfur by sulfate-reducing bacteria. | sulfate reducers and related organisms which had previously been found to reduce fe(iii) with h(2) or organic electron donors oxidized s to sulfate when mn(iv) was provided as an electron acceptor. organisms catalyzing this reaction in washed cell suspensions included desulfovibrio desulfuricans, desulfomicrobium baculatum, desulfobacterium autotrophicum, desulfuromonas acetoxidans, and geobacter metallireducens. these organisms produced little or no sulfate from s with fe(iii) as a potential el ... | 1994 | 16349323 |
| anaerobic degradation of propionate by a mesophilic acetogenic bacterium in coculture and triculture with different methanogens. | a mesophilic acetogenic bacterium (mpob) oxidized propionate to acetate and co(2) in cocultures with the formate- and hydrogen-utilizing methanogens methanospirillum hungatei and methanobacterium formicicum. propionate oxidation did not occur in cocultures with two methanobrevibacter strains, which grew only with hydrogen. tricultures consisting of mpob, one of the methanobrevibacter strains, and organisms which are able to convert formate into h(2) plus co(2) (desulfovibrio strain g11 or the ho ... | 1994 | 16349350 |
| metabolic pathways leading to mercury methylation in desulfovibrio desulfuricans ls. | the synthesis of methylmercury by desulfovibrio desulfuricans ls was investigated on the basis of c incorporation from precursors and the measurement of relevant enzyme activities in cell extracts. the previously observed incorporation of c-3 from serine into methylmercury was confirmed by measurement of relatively high activities of serine hydroxymethyltransferase and other enzymes of this pathway. high rates of label incorporation into methylmercury from hcoo and hco(3) prompted the assay of e ... | 1994 | 16349435 |
| oxygen consumption by desulfovibrio strains with and without polyglucose. | the kinetics of oxygen reduction by desulfovibrio salexigens mast1 and the role of polyglucose in this activity were examined and compared with those of strains of d. desulfuricans and d. gigas. oxidation rates were highest at air saturation (up to 40 nmol of o(2) min mg of protein) and declined with decreasing oxygen concentrations. studies with cell extracts (ce) indicated that nadh oxidase was entirely responsible for the oxygen reduction in strain mast1. in d. desulfuricans csn, at least thr ... | 1998 | 16349510 |
| a versatile and sensitive tritium-based radioassay for measuring hydrogenase activity in aquatic sediments. | we present a method for the measurement of hydrogenase (h(2)ase) activity in aquatic sediments. the assay is based on the h(2)ase-mediated isotopic exchange between dissolved molecular hydrogen (h(2)) and water. a slurry of sediment material is incubated with a tritiated hydrogen (ht) headspace in a glass syringe on a rotary shaker. the method includes a procedure for preparing ht from radiolabeled sodium borohydride, which is a useful alternative to purchasing ht directly. a method for measurin ... | 2006 | 16356571 |
| electrochemical definitions of o2 sensitivity and oxidative inactivation in hydrogenases. | a new strategy is described for comparing, quantitatively, the ability of hydrogenases to tolerate exposure to o2 and anoxic oxidizing conditions. using protein film voltammetry, the inherent sensitivities to these challenges (thermodynamic potentials and rates of reactions) have been measured for enzymes from a range of mesophilic microorganisms. in the absence of o2, all the hydrogenases undergo reversible inactivation at various potentials above that of the h+/h2 redox couple, and h2 oxidatio ... | 2005 | 16366571 |
| toxic effects of dissolved heavy metals on desulfovibrio vulgaris and desulfovibrio sp. strains. | biological treatment of metal-containing wastewaters with sulphate-reducing bacteria (srb) is an attractive technique for the bioremediation of this kind of medium. in order to design a suitable engineering process to address this environmental problem, it is crucial to understand the inhibitory effect of dissolved heavy metals on these bacteria. batch studies were carried out to evaluate the toxic effects of several heavy metal ions [cr(iii), cu(ii), mn(ii), ni(ii) and zn(ii)] on two cultures o ... | 2006 | 16386832 |
| characterization of the desulfovibrio desulfuricans atcc 27774 dsrmkjop complex--a membrane-bound redox complex involved in the sulfate respiratory pathway. | sulfate-reducing organisms use sulfate as an electron acceptor in an anaerobic respiratory process. despite their ubiquitous occurrence, sulfate respiration is still poorly characterized. genome analysis of sulfate-reducing organisms sequenced to date permitted the identification of only two strictly conserved membrane complexes. we report here the purification and characterization of one of these complexes, dsrmkjop, from desulfovibrio desulfuricans atcc 27774. the complex has hemes of the c an ... | 2006 | 16388601 |
| [sulfate-reducing bacteria in gypsum karst lakes of northern lithuania]. | microbiological studies were performed in three small gypsum karst lakes in northern lithuania, most typical of the region. samples were taken in different seasons of 2001. the conditions for microbial growth in the lakes are determined by elevated content of salts (from 0.5 to 2.0 g/l), dominated by so(2-)4 and ca2+ ions (up to 1.4 and 0.6 g/l, respectively). the elevated sulfate concentration is favorable for sulfate-reducing bacteria (srbs). summer and winter stratification gives rise to anae ... | 2005 | 16400994 |
| geometries and electronic structures of cyanide adducts of the non-heme iron active site of superoxide reductases: vibrational and endor studies. | we have added cyanide to oxidized 1fe and 2fe superoxide reductase (sor) as a surrogate for the putative ferric-(hydro)peroxo intermediate in the reaction of the enzymes with superoxide and have used vibrational and endor spectroscopies to study the properties of the active site paramagnetic iron center. addition of cyanide changes the active site iron center in oxidized sor from rhombic high-spin ferric (s = 5/2) to axial-like low-spin ferric (s = 1/2). low-temperature resonance raman and endor ... | 2006 | 16401073 |
| mechanism of nitrate reduction by desulfovibrio desulfuricans nitrate reductase--a theoretical investigation. | the oxidative half-reaction of oxygen atom transfer from nitrate to an mo(iv) complex has been investigated at various levels of theory. two models have been used to simulate the enzyme active site. in the second, more advanced model, additional amino acid residues capable of significantly affecting the catalytic efficiency of the enzyme were included. b3lyp/6-31+g*, oniom, and orbital-free embedding approaches have been used to construct the potential energy profile and to qualitatively compare ... | 2006 | 16411255 |
| comparison of the structural and kinetic properties of the cytochrome c nitrite reductases from escherichia coli, wolinella succinogenes, sulfurospirillum deleyianum and desulfovibrio desulfuricans. | the recent crystallographic characterization of nrfas from sulfurospirillum deleyianum, wolinella succinogenes, escherichia coli and desulfovibrio desulfuricans allows structurally conserved regions to be identified. comparison of nitrite and sulphite reductase activities from different bacteria shows that the relative activities vary according to organism. by comparison of both amino acid sequences and structures, differences can be identified in the monomer-monomer interface and the active-sit ... | 2006 | 16417505 |
| analysis of aerotactic band formation by desulfovibrio desulfuricans in a stopped-flow diffusion chamber. | aerotactic band formation by desulfovibrio desulfuricans (dsm 9104) was studied in a stopped-flow diffusion chamber. this chamber allowed us to create reproducible, steep oxygen gradients in a flat capillary, time-lapse video recordings and spatio-temporal analysis of band formation. the cells formed two types of bands. bands of the first type evolved quickly after starting the experiment and were located near the oxic-anoxic interface. bands of the second type typically appeared several minutes ... | 2006 | 16420627 |
| studies on the effect of system retention time on bacterial populations colonizing a three-stage continuous culture model of the human large gut using fish techniques. | fluorescence in situ hybridization was used to quantitate bacteria growing in a three-stage continuous culture system inoculated with human faeces, operated at two system retention times (60 and 20 h). twenty-three different 16s rrna gene oligonucleotide probes of varying specificities were used to detect bacteria. organisms belonging to genera bacteroides and bifidobacterium, together with the eubacterium rectale/clostridium coccoides group, the atopobium, faecalibacterium prausnitzii and eubac ... | 2006 | 16420637 |
| native-specific stabilization of flavodoxin by the fmn cofactor: structural and thermodynamical explanation. | flavodoxins are useful models to investigate protein/cofactor interactions. the binding energy of the apoflavodoxin-fmn complex is high and therefore the holoflavodoxin is expected to be more stable than the apoprotein. this expectation has been challenged by reports on the stability of desulfovibrio desulfuricans flavodoxin indicating that fmn binds to the unfolded polypeptide with similar affinity as to the native state, thus causing no net effect on protein stability. in previous work, we hav ... | 2006 | 16444751 |
| desulfovibrio gigas ferredoxin ii: redox structural modulation of the [3fe-4s] cluster. | desulfovibrio gigas ferredoxin ii (dgfdii) is a small protein with a polypeptide chain composed of 58 amino acids, containing one fe3s4 cluster per monomer. upon studying the redox cycle of this protein, we detected a stable intermediate (fdiiint) with four 1h resonances at 24.1, 20.5, 20.8 and 13.7 ppm. the differences between fdiiox and fdiiint were attributed to conformational changes resulting from the breaking/formation of an internal disulfide bridge. the same 1h nmr methodology used to fu ... | 2006 | 16453120 |
| periplasmic superoxide dismutase from desulfovibrio desulfuricans 1388 is an iron protein. | it is shown that the genome of the sulfate-reducing bacterium desulfovibrio desulfuricans 1388 contains a superoxide dismutase (sod) gene (sod). the gene encodes an export signal peptide characteristic for periplasmic redox proteins. the amino acid sequence showed high homology with iron-containing sods from other bacteria. electrophoretically pure sod was isolated from the periplasmic fraction of bacterial cells by fplc chromatography. like other fe-sods, d. desulfuricans 1388 superoxide dismut ... | 2006 | 16457621 |
| redox interaction of cytochrome c3 with [nife] hydrogenase from desulfovibrio vulgaris miyazaki f. | cytochrome c3 isolated from a sulfate-reducing bacterium, desulfovibrio vulgaris miyazaki f, is a tetraheme protein. its physiological partner, [nife] hydrogenase, catalyzes the reversible oxidoreduction of molecular hydrogen. to elucidate the mechanism of electron transfer between cytochrome c3 and [nife] hydrogenase, the transient complex formation by these proteins was investigated by means of nmr. all nh signals of uniformly 15n-labeled ferric cytochrome c3 except n-terminus, pro, and gly73 ... | 2006 | 16460012 |
| global analysis of heat shock response in desulfovibrio vulgaris hildenborough. | desulfovibrio vulgaris hildenborough belongs to a class of sulfate-reducing bacteria (srb) and is found ubiquitously in nature. given the importance of srb-mediated reduction for bioremediation of metal ion contaminants, ongoing research on d. vulgaris has been in the direction of elucidating regulatory mechanisms for this organism under a variety of stress conditions. this work presents a global view of this organism's response to elevated growth temperature using whole-cell transcriptomics and ... | 2006 | 16484192 |
| biorecovered precious metals from industrial wastes: single-step conversion of a mixed metal liquid waste to a bioinorganic catalyst with environmental application. | the complete and continuous reduction of 1 mm cr(vi) to cr(iii) was achieved in a flow-through reactor using a novel bioinorganic catalyst ("mm-bio-pd(0)"), which was produced by single-step reduction of platinum group metals (pgm) from industrial waste solution onto biomass of desulfovibrio desulfuricans atcc 29577. two flow-through reactor systems were compared using both "mm-biopd(0)" and chemically reduced pd(0). reactors containing the latter removed cr(vi) for 1 week only at the expense of ... | 2006 | 16509351 |
| specific binding of co to tetraheme cytochrome c3. | carbon monoxide (co) has been identified as another bioactive molecule like no. binding of co to a tetraheme cytochrome c(3) (cyt c(3)) was investigated using visible absorption spectroscopy, circular dichroism (cd), and nmr. co was found to bind to the four hemes in different manners. cd spectra, however, indicated that only single-site co binding can keep the protein intact. the k(d) for the single-site binding was 8.0 microm, which is a typical value for a co sensor protein. furthermore, nmr ... | 2006 | 16519511 |
| solution structures of tetrahaem ferricytochrome c3 from desulfovibrio vulgaris (hildenborough) and its k45q mutant: the molecular basis of cooperativity. | the nmr structure of the oxidised wild-type cytochrome c3 from desulfovibrio vulgaris hildenborough was determined in solution. using a newly developed methodology, nmr data from the k45q mutant was then grafted onto data from the wild-type protein to determine the structure in the region of the mutation. the structural origins of the redox-bohr effect and haem-haem cooperativities are discussed with respect to the redox-related conformational changes observed in solution. | 2006 | 16527248 |