Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| displacement of iron by zinc at the diiron site of desulfovibrio vulgaris rubrerythrin: x-ray crystal structure and anomalous scattering analysis. | x-ray crystal structures of recombinant desulfovibrio (d.) vulgaris rubrerythrin (rbr) have shown a diiron site, whereas the crystal structure of rbr "as-isolated" from d. vulgaris was reported to contain a mixed zn,fe binuclear site. to investigate the possibility that zinc had displaced iron during isolation or crystallization of the "as-isolated" d. vulgaris rbr, the x-ray crystal structure of recombinant d. vulgaris all-iron rbr that had been incubated with excess zinc sulfate prior to cryst ... | 2004 | 15134924 |
| antagonists mo and cu in a heterometallic cluster present on a novel protein (orange protein) isolated from desulfovibrio gigas. | an orange-coloured protein (orp) isolated from desulfovibrio gigas, a sulphate reducer, has been previously shown by extended x-ray absorption fine structure (exafs) to contain a novel mixed-metal sulphide cluster of the type [s(2)mos(2)cus(2)mos(2)] [j. am. chem. soc. 122 (2000) 8321]. we report here the purification and the biochemical/spectroscopic characterisation of this novel protein. orp is a soluble monomeric protein (11.8 kda). the cluster is non-covalently bound to the polypeptide chai ... | 2004 | 15134929 |
| relativistic dft calculation of the reaction cycle intermediates of [nife] hydrogenase: a contribution to understanding the enzymatic mechanism. | structures and spectroscopic observables of the paramagnetic intermediates of the enzymatic reaction cycle of the metalloenzyme [nife] hydrogenase were calculated using relativistic density functional theory (dft) within the zero-order regular approximation (zora). by comparing experimental and calculated magnetic resonance parameters (g- and hyperfine tensors) for the states ni-a, ni-b, ni-c, ni-l, and ni-co the details of the atomic composition of these paramagnetic intermediates could be eluc ... | 2004 | 15134933 |
| 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase: head-to-head with a bifunctional enzyme that controls glycolysis. | fru-2,6-p2 (fructose 2,6-bisphosphate) is a signal molecule that controls glycolysis. since its discovery more than 20 years ago, inroads have been made towards the understanding of the structure-function relationships in pfk-2 (6-phosphofructo-2-kinase)/fbpase-2 (fructose-2,6-bisphosphatase), the homodimeric bifunctional enzyme that catalyses the synthesis and degradation of fru-2,6-p2. the fbpase-2 domain of the enzyme subunit bears sequence, mechanistic and structural similarity to the histid ... | 2004 | 15170386 |
| susceptibility of desulfovibrio desulfuricans intestinal strains to sulfasalazine and its biotransformation products. | desulfovibrio desulfuricans intestinal bacteria may contribute to toxic hydrogen sulfide production in the human gut. our objective was to examine whether the d. desulfuricans strains isolated from the human body are susceptible to sulfasalazine (sas) and the products of its biotransformation, i.e. 5-aminosalicylic acid (5-asa) and sulfapyridine (sp), in order to determine the relationship between the strains' susceptibility to sas and their ability to reduce the azo bond within this drug. | 2004 | 15173665 |
| ftir spectroelectrochemical study of the activation and inactivation processes of [nife] hydrogenases: effects of solvent isotope replacement and site-directed mutagenesis. | the kinetics of the activation and anaerobic inactivation processes of desulfovibrio gigas hydrogenase have been measured in d(2)o by ftir spectroelectrochemistry. a primary kinetic solvent isotope effect was observed for the inactivation process but not for the activation step. the kinetics of these processes have been also measured after replacement of a glutamic residue placed near the active site of an analogous [nife] hydrogenase from desulfovibrio fructosovorans. its replacement by a gluta ... | 2004 | 15175937 |
| characterization of bacterial communities in feces from healthy elderly volunteers and hospitalized elderly patients by using real-time pcr and effects of antibiotic treatment on the fecal microbiota. | fecal bacteria were studied in healthy elderly volunteers (age, 63 to 90 years; n = 35) living in the local community, elderly hospitalized patients (age, 66 to 103; n = 38), and elderly hospitalized patients receiving antibiotic treatment (age, 65 to 100; n = 21). group- and species-specific primer sets targeting 16s rrna genes were used to quantitate intestinal bacteria by using dna extracted from feces and real-time pcr. the principal difference between healthy elderly volunteers and both pat ... | 2004 | 15184159 |
| overexpression, purification and immunodetection of dsrd from desulfovibrio vulgaris hildenborough. | dissimilatory sulfite reductase (dsrab) of the sulfate-reducing bacterium desulfovibrio vulgaris hildenborough is an alpha2beta2 tetramer of 180 kda, encoded by the dsr operon. in addition to the dsra and dsrb genes, this operon contains a gene (dsrd) encoding a protein of only 78 amino acids. although, the function of dsrd is currently unknown, the presence of a dsrd gene has been demonstrated in a variety of sulfate-reducing bacteria and archaea. dsrd was expressed in escherichia coli at a ver ... | 2000 | 15188893 |
| dynamics of lead immobilization in sulfate reducing biofilms. | we have evaluated the effects of selected minerals present in subsoil environment on the efficiency of lead removal from contaminated groundwaters using biofilms composed of sulfate-reducing microorganisms, and examined the stability of metal deposits after the biofilms had been temporarily exposed to the air. to quantify the studied effects, lead was immobilized in biofilms of desulfovibrio desulfuricans grown anaerobically in two flat-plate flow reactors, one filled with hematite and the other ... | 2004 | 15207603 |
| reduction of cr(vi) by "palladized" biomass of desulfovibrio desulfuricans atcc 29577. | a novel catalytic activity of palladium [pd(0)]-coated cells of desulfovibrio desulfuricans atcc 29577 ["bio-pd(0)"] is demonstrated. reduction of 700 microm cr(vi) occurred within 24 h using formate (25 mm) or hydrogen (1 atm) as the electron donor, under conditions whereby cells lacking bound pd(0), or palladium metal manufactured via chemical reduction of soluble pd(ii), did not reduce cr(vi). the biomass-bound pd(0) also functioned in the continuous removal of 400 microm cr(vi) from a 1 mm s ... | 2004 | 15211494 |
| structural stability of adenylate kinase from the sulfate-reducing bacteria desulfovibrio gigas. | a novel adenylate kinase (ak) has recently been purified from desulfovibrio gigas and characterized as a co(2+)/zn(2+)-containing enzyme: this is an unusual characteristic for aks from gram-negative bacteria, in which these enzymes are normally devoid of metals. here, we studied the conformational stability of holo- and apo-ak as a function of temperature by differential scanning calorimetry (dsc), circular dichroism (cd), and intrinsic fluorescence spectroscopy. the thermal unfolding of ak is a ... | 2004 | 15223146 |
| uranium complexes formed at hematite surfaces colonized by sulfate-reducing bacteria. | modeling uranium (u) transport in subsurface environments requires a thorough knowledge of mechanisms likely to restrict its mobility, such as surface complexation, precipitation, and colloid formation. in closed systems, sulfate-reducing bacteria (srb) such as desulfovibrio spp. demonstrably affect u immobilization by enzymatic reduction of u(vi) species (primarily the uranyl ion, uo2(2+), and its complexes) to u(iv). however, our understanding of such interactions under chronic u(vi) exposure ... | 2004 | 15224730 |
| adjacent cysteines are capable of ligating the same tetranuclear iron-sulfur cluster. | the mechanism of the energy-converting nadh (beta-nicotinamide adenine dinucleotide, reduced form):ubiquinone oxidoreductase, which is also called respiratory complex i, is largely unknown due to lack of a high-resolution structure and the most complicated construction of the enzyme. electron transport is carried out by one flavin mononucleotide (fmn) and up to 9 fe/s clusters. the fe/s cluster n2, which is believed to be directly involved in redox-coupled proton-translocation, is located on sub ... | 2004 | 15229887 |
| chalk and cheese. | 2004 | 15248310 | |
| x-ray crystal structure and epr spectra of "arsenite-inhibited" desulfovibriogigas aldehyde dehydrogenase: a member of the xanthine oxidase family. | x-ray crystallography has been used to determine the structure of arsenite-inhibited aldehyde dehydrogenase from desulfovibrio gigas, a member of the xanthine oxidase family of mononuclear molybdenum enzymes. the structure shows an aso3 moiety bound to the molybdenum atom of the active site through one of the oxygen atoms. a reduced sample of arsenite-inhibited aldehyde dehydrogenase has a mo(v) signal that shows anisotropic hyperfine and quadrupole coupling to one arsenic atom. this signal has ... | 2004 | 15250689 |
| looking at big brothers for clues. | 2004 | 15250878 | |
| genome update: annotation quality in sequenced microbial genomes. | 2004 | 15256543 | |
| impact of clay minerals on sulfate-reducing activity in aquifers. | previous studies have shown that sulfate-reduction activity occurs in a heterogeneous manner throughout the terrestrial subsurface. low-activity regions are often observed in the presence of clay minerals. here we report that clays inhibit sulfate reduction activity in sediments and in a pure culture of desulfovibrio vulgaris. clay minerals including bentonite and kaolinite inhibited sulfate reduction by 70-90% in sediments. intact clays and clay colloids or soluble components, capable of passin ... | 2004 | 15259272 |
| toxicity and degradation of metal-complexed cyanide by a bacterial consortium under sulfate-reducing conditions. | free cyanide at 1 mm decreased the initial sulfate reduction rate of a batch culture of granular sludge from 0.3 to 0.14 mmol d(-1) g(-1) ss (suspended solid), whereas 0.5 mm cyanide had a minimal effect (0.25 mmol d(-1) g(-1) ss). the order of toxicity of metal-complexed cyanides to the sludge was as follows: zinc-complexed cyanide (most toxic) > free cyanide = nickel-complexed cyanide > copper-complexed cyanide (least toxic), which also corresponds well with the order of the stability (dissoci ... | 2004 | 15269528 |
| computational prediction of conserved operons and phylogenetic footprinting of transcription regulatory elements in the metal-reducing bacterial family geobacteraceae. | members of the family geobacteraceae are an important group of microorganisms from the delta subdivision of proteobacteria that couple the oxidation of organic compounds to metal reduction. in order to uncover transcription regulatory interactions in these organisms, we used computational methods to identify conserved operons and putative cis-regulatory transcription elements. we identified 26 putative operons with gene order and function conserved among two species of geobacteraceae, geobacter ... | 2004 | 15276006 |
| polyhydroxyalkanoate (pha) accumulation in sulfate-reducing bacteria and identification of a class iii pha synthase (phaec) in desulfococcus multivorans. | seven strains of sulfate-reducing bacteria (srb) were tested for the accumulation of polyhydroxyalkanoates (phas). during growth with benzoate desulfonema magnum accumulated large amounts of poly(3-hydroxybutyrate) [poly(3hb)]. desulfosarcina variabilis (during growth with benzoate), desulfobotulus sapovorans (during growth with caproate), and desulfobacterium autotrophicum (during growth with caproate) accumulated poly(3hb) that accounted for 20 to 43% of cell dry matter. desulfobotulus sapovor ... | 2004 | 15294771 |
| location of active sites of nife hydrogenase determined by the combination of multiple isomorphous replacement and multiwavelength anomalous-diffraction methods. | the active centers of nife hydrogenase from desulfovibrio vulgaris miyazaki f have been located in the electron-density map calculated at 4 a resolution. the electron-density map based on five heavy-atom derivatives showed four strong peaks which were clearly distinguished from the protein region. these strong densities have been successfully assigned to three iron-sulfur clusters and one ni atom by a difference fourier technique with coefficients of the best phases from the multiple isomorphous ... | 1994 | 15299378 |
| crystallization and preliminary x-ray diffraction analysis of tetra-heme cytochrome c3 from sulfate- and nitrate-reducing desulfovibrio desulfuricans atcc 27774. | crystals of the tetra-heme cytochrome c(3) (m(r) = 13 kda, 107 residues, four heme groups) from sulfate- and nitrate-reducing desulfovibrio desulfuricans atcc 27774 have been obtained and crystallographically characterized. they belong to space group p6(1)22 with cell dimensions a = b = 61.84 (4) and c = 109.7 (2) a, and z = 12. intensity data were initially collected on a fast system with a rotating-anode x-ray source leading to a total of 22 592 observations, from which only 4930 were unique, ... | 1994 | 15299466 |
| the application of direct methods and patterson interpretation to high-resolution native protein data. | conventional small-molecule methods of solving the phase problem from native data alone, without the use of heavy-atom derivatives, known fragment geometries or anomalous dispersion, have been tested on 0.9 a resolution data for two small proteins: rubredoxin, from desulfovibrio vulgaris, and crambin. the presence of three disulfide bridges in crambin and an fes(4) unit in rubredoxin enabled automated patterson interpretation as well as direct methods to be tried. although both structures were a ... | 1993 | 15299542 |
| preliminary crystallographic analysis and further characterization of a dodecaheme cytochrome c from desulfovibrio desulfuricans atcc 27774. | dodecaheme cytochrome c has been purified from desulfovibrio (d.) desulfuricans atcc 27774 cells grown under both nitrate and sulfate-respiring conditions. therefore, it is likely to play a role in the electron-transfer system of both respiratory chains. its molecular mass (37768 kda) was determined by electrospray mass spectrometry. its first 39 amino acids were sequenced and a motif was found between amino acids 32 and 37 that seems to exist in all the cytochromes of the c(3) type from sulfate ... | 1996 | 15299587 |
| crystallization and preliminary x-ray crystallographic analysis of the putative [6fe-6s] prismane protein from desulfovibrio vulgaris (hildenborough). | crystals of the prismane protein from desulfovibrio vulgaris (hildenborough) containing a putative [6fe-6s] cluster have been obtained and x-ray data collected to a resolution of 1.7 a using synchrotron radiation. the unit cell is orthorhombic with a = 64.1, b = 65.1 and c = 154.1 a, space group p2(1)2(1)2(1) (no. 19). the unit cell will readily accommodate four molecules of molecular weight 60 kda with a corresponding solvent content of approximately 48%. | 1996 | 15299589 |
| the genome of desulfotalea psychrophila, a sulfate-reducing bacterium from permanently cold arctic sediments. | desulfotalea psychrophila is a marine sulfate-reducing delta-proteobacterium that is able to grow at in situ temperatures below 0 degrees c. as abundant members of the microbial community in permanently cold marine sediments, d. psychrophila-like bacteria contribute to the global cycles of carbon and sulfur. here, we describe the genome sequence of d. psychrophila strain lsv54, which consists of a 3 523 383 bp circular chromosome with 3118 predicted genes and two plasmids of 121 586 bp and 14 66 ... | 2004 | 15305914 |
| changes in the nitrocellulose molecule induced by sulfate-reducing bacteria desulfovibrio desulfuricans 1,388. the enzymes participating in this process. | the appearance of unsubstituted glucopyranose residues in nitrocellulose (nc) induced by desulfovibrio desulfuricans was established by (13)c-nmr spectroscopy. after contact with bacterial cells, the degree of substitution by nitro groups in nc decreased from 2.59 to 2.40. the bacteria possess intra- and extracellular nitroesterase activities, which are responsible for denitration of the polymer. the presence of nc in the growth medium influences the extracellular nitroesterase activity. it is s ... | 2004 | 15310283 |
| roles of noncoordinated aromatic residues in redox regulation of cytochrome c3 from desulfovibrio vulgaris miyazaki f. | the roles of aromatic residues in redox regulation of cytochrome c(3) were investigated by site-directed mutagenesis at every aromatic residue except for axial ligands (phe20, tyr43, tyr65, tyr66, his67, and phe76). the mutations at phe20 induced large chemical shift changes in the nmr signals for hemes 1 and 3, and large changes in the microscopic redox potentials of hemes 1 and 3. the nmr signals of the axial ligands of hemes 1 and 3 were also affected. analysis of the nature of the mutations ... | 2004 | 15323546 |
| overexpression and purification of treponema pallidum rubredoxin; kinetic evidence for a superoxide-mediated electron transfer with the superoxide reductase neelaredoxin. | superoxide reductases are a class of non-haem iron enzymes which catalyse the monovalent reduction of the superoxide anion o2- into hydrogen peroxide and water. treponema pallidum (tp), the syphilis spirochete, expresses the gene for a superoxide reductase called neelaredoxin, having the iron protein rubredoxin as the putative electron donor necessary to complete the catalytic cycle. in this work, we present the first cloning, overexpression in escherichia coli and purification of the tp rubredo ... | 2004 | 15328557 |
| structure of superoxide reductase bound to ferrocyanide and active site expansion upon x-ray-induced photo-reduction. | some sulfate-reducing and microaerophilic bacteria rely on the enzyme superoxide reductase (sor) to eliminate the toxic superoxide anion radical (o2*-). sor catalyses the one-electron reduction of o2*- to hydrogen peroxide at a nonheme ferrous iron center. the structures of desulfoarculus baarsii sor (mutant e47a) alone and in complex with ferrocyanide were solved to 1.15 and 1.7 a resolution, respectively. the latter structure, the first ever reported of a complex between ferrocyanide and a pro ... | 2004 | 15341736 |
| a theoretical study of spin states in ni-s4 complexes and models of the [nife] hydrogenase active site. | we have applied density functional theory, using both pure (bp86) and hybrid (b3lyp and b3lyp*) functionals, to investigate structural parameters and reaction energies for nickel(ii)-sulfur coordination compounds, as well as for small cluster models of the ni-si and ni-r redox state of [nife] hydrogenases. results obtained investigating experimentally well-characterized complexes show that bp86 is well suited to describe the structural features of this class of compounds. however, the singlet-tr ... | 2004 | 15365900 |
| roll with the flow: microbial masters of redox chemistry. | 2004 | 15381191 | |
| inhibition and aerobic inactivation kinetics of desulfovibrio fructosovorans nife hydrogenase studied by protein film voltammetry. | we have used protein film voltammetry to study the nife hydrogenase from desulfovibrio fructosovorans. we show how measurements of transient activity following the addition in the electrochemical cell of h(2), co, or o(2) allow simple and virtually instantaneous determinations of the michaelis constant, inhibition constant, or rate of inactivation, respectively, thus opening new opportunities to study the active site of nife hydrogenases. the binding and release of co occur within a fraction of ... | 2004 | 15382953 |
| epr spectroscopy of protein microcrystals oriented in a liquid crystalline polymer medium. | correlation of the g-tensor of a paramagnetic active center of a protein with its structure provides a unique experimental information on the electronic structure of the metal site. to address this problem, we made solid films containing metalloprotein (desulfovibrio gigas cytochrome c(3)) microcrystals. the microcrystals in a liquid crystalline polymer medium (water/hydroxypropylcellulose) were partially aligned by a shear flow. a strong orientation effect of the metalloprotein was observed by ... | 2004 | 15388083 |
| desulfovibrio bastinii sp. nov. and desulfovibrio gracilis sp. nov., moderately halophilic, sulfate-reducing bacteria isolated from deep subsurface oilfield water. | two moderately halophilic, mesophilic, sulfate-reducing bacteria were isolated from production-water samples from emeraude oilfield, congo. motile, vibrioid cells of srl4225t grew optimally at a concentration of 4 % nacl, at ph 5.8-6.2, with a minimal ph for growth of 5.2, showing that it is a moderately acidophilic bacterium. cells of srl6146t were motile, curved or vibrioid, long and thin rods. optimal growth was obtained at a concentration of 5-6 % nacl, at ph 6.8-7.2. the nutritional require ... | 2004 | 15388730 |
| desulfovibrio alaskensis sp. nov., a sulphate-reducing bacterium from a soured oil reservoir. | a novel sulphate-reducing bacterium (al1t) was recovered from a soured oil well in purdu bay, alaska. light and atomic force microscopy observations revealed that cells were gram-negative, vibrio-shaped and motile by means of a single polar flagellum. the carbon and energy sources used by the isolate and the salinity, temperature and ph ranges facilitating its growth proved to be typical of a partial lactate-oxidizing, moderately halophilic, mesophilic, sulphate-reducing bacterium. analysis of t ... | 2004 | 15388739 |
| [stages of biofilm formation by sulfate-reducing bacteria]. | taxis to fe3+ ions and adhesion to steel-3 of sulphate-reducing bacteria different by corrosion activity have been investigated. it has been shown that taxis activity of cells from the postgate medium "b" was higher than from the buffer. aggressive strains desulfovibrio indonensis, desulfovibrio sp. possessed higher activity taxis with respect to fe3+ ions. it has been noted that aggressive strains of sulphate-reducing bacteria adhered more actively to the steel surface and formed more powerful ... | 2004 | 15456221 |
| thermal unfolding of apo and holo desulfovibrio desulfuricans flavodoxin: cofactor stabilizes folded and intermediate states. | we here compare thermal unfolding of the apo and holo forms of desulfovibrio desulfuricans flavodoxin, which noncovalently binds a flavin mononucleotide (fmn) cofactor. in the case of the apo form, fluorescence and far-uv circular dichroism (cd) detected transitions are reversible but do not overlap (t(m) of 50 and 60 degrees c, respectively, ph 7). the thermal transitions for the holo form follow the same pattern but occur at higher temperatures (t(m) of 60 and 67 degrees c for fluorescence and ... | 2004 | 15461458 |
| bacterial community associated with black band disease in corals. | black band disease (bbd) is a virulent polymicrobial disease primarily affecting massive-framework-building species of scleractinian corals. while it has been well established that the bbd bacterial mat is dominated by a cyanobacterium, the quantitative composition of the bbd bacterial mat community has not described previously. terminal-restriction fragment length polymorphism (t-rflp) analysis was used to characterize the infectious bacterial community of the bacterial mat causing bbd. these a ... | 2004 | 15466538 |
| isolation of sulfate-reducing bacteria from the terrestrial deep subsurface and description of desulfovibrio cavernae sp. nov. | deep subsurface sandstones in the area of berlin (germany) located 600 to 1060 m below the surface were examined for the presence of viable microorganisms. the in situ temperatures at the sampling sites ranged from 37 to 45 degrees c. investigations focussed on sulfate-reducing bacteria able to grow on methanol and triethylene glycol, which are added as chemicals to facilitate the long-term underground storage of natural gas. seven strains were isolated from porewater brines in the porous sandst ... | 2004 | 15490555 |
| cofactor-apoprotein hydrogen bonding in oxidized and fully reduced flavodoxin monitored by trans-hydrogen-bond scalar couplings. | hydrogen bonding plays a key role in the tight binding of the fmn cofactor and the regulation of its redox properties in flavodoxins. hydrogen bonding interactions can be directly observed in solution by multidimensional heteronuclear nmr spectroscopy through the scalar couplings between donor and acceptor nuclei. here we report on the detection of intermolecular trans-hydrogen-bond couplings ((h)j) between the flavin ring system and the backbone of desulfovibrio vulgaris flavodoxin in the oxidi ... | 2004 | 15515086 |
| [effect of corrosion inhibitor on adhesion of sulfate-reducing bacteria to steel and their production of exopolymer complex]. | it was shown in the laboratory investigations that the cells of sulphate-reducing bacteria of both aggressive desulfovibrio sp. strain kiev-10 and nonaggressive desulfovibrio desulfuricans strain kiev-45 strains can produce exopolysaccharides (eps). plankton (freely floating) cells of sulphate-reducing bacteria produce greater quantity of eps than the cells of the biofilm formed on steel. the inducing effect of metal on eps synthesis by sulphate-reducing bacteria has been established. the conten ... | 2004 | 15515905 |
| direct monitoring of the electron pool effect of cytochrome c3 by highly sensitive eqcm measurements. | cytochrome c(3) from desulfovibrio vulgaris has four hemes per molecule, and a redox change at the hemes alters the conformation of the protein, leading to a redox-dependent change in the interaction of cytochrome c(3) with redox partners (an electron acceptor or an electron donor). the redox-dependent change in this interaction was directly monitored by the high-performance electrochemical quartz crystal microbalance (eqcm) technique that has been improved to give high sensitivity in solution. ... | 2004 | 15517437 |
| reconstruction of regulatory and metabolic pathways in metal-reducing delta-proteobacteria. | relatively little is known about the genetic basis for the unique physiology of metal-reducing genera in the delta subgroup of the proteobacteria. the recent availability of complete finished or draft-quality genome sequences for seven representatives allowed us to investigate the genetic and regulatory factors in a number of key pathways involved in the biosynthesis of building blocks and cofactors, metal-ion homeostasis, stress response, and energy metabolism using a combination of regulatory ... | 2004 | 15535866 |
| physiological and gene expression analysis of inhibition of desulfovibrio vulgaris hildenborough by nitrite. | a desulfovibrio vulgaris hildenborough mutant lacking the nrfa gene for the catalytic subunit of periplasmic cytochrome c nitrite reductase (nrfha) was constructed. in mid-log phase, growth of the wild type in medium containing lactate and sulfate was inhibited by 10 mm nitrite, whereas 0.6 mm nitrite inhibited the nrfa mutant. lower concentrations (0.04 mm) inhibited the growth of both mutant and wild-type cells on plates. macroarray hybridization indicated that nitrite upregulates the nrfha ge ... | 2004 | 15547266 |
| sulfate-reducing bacteria in tubes constructed by the marine infaunal polychaete diopatra cuprea. | marine infaunal burrows and tubes greatly enhance solute transport between sediments and the overlying water column and are sites of elevated microbial activity. biotic and abiotic controls of the compositions and activities of burrow and tube microbial communities are poorly understood. the microbial communities in tubes of the marine infaunal polychaete diopatria cuprea collected from two different sediment habitats were examined. the bacterial communities in the tubes from a sandy sediment di ... | 2004 | 15574900 |
| multiple orientations in a physiological complex: the pyruvate-ferredoxin oxidoreductase-ferredoxin system. | ferredoxin i from desulfovibrio africanus (da fdi) is a small acidic [4fe-4s] cluster protein that exchanges electrons with pyruvate-ferredoxin oxidoreductase (pfor), a key enzyme in the energy metabolism of anaerobes. the thermodynamic properties and the electron transfer between pfor and either native or mutated fdi have been investigated by microcalorimetry and steady-state kinetics, respectively. the association constant of the pfor-fdi complex is 3.85 x 10(5) m(-1), and the binding affinity ... | 2004 | 15581360 |
| continuous removal of cr(vi) from aqueous solution catalysed by palladised biomass of desulfovibrio vulgaris. | growth-decoupled cells of desulfovibrio vulgaris ncimb 8303 can be used to reduce pd(ii) to cell-bound pd(0) (bio-pd(0)), a bioinorganic catalyst capable of reducing hexavalent chromium to less toxic cr(iii), using formate as the electron donor. magnetic resonance imaging showed that bio-pd(0), immobilized in chitosan and agar beads, is distinguishable from the surrounding gel and is evenly dispersed within the immobilization matrix. agar-immobilized bio-pd(0) and 'chemical pd(0)' were packed in ... | 2004 | 15604792 |
| an orientation-selected endor and hyscore study of the ni-c active state of desulfovibrio vulgaris miyazaki f hydrogenase. | electron nuclear double resonance (endor) and hyperfine sublevel correlation spectroscopy (hyscore) are applied to study the active site of catalytic [nife]-hydrogenase from desulfovibrio vulgaris miyazaki f in the reduced ni-c state. these techniques offer a powerful tool for detecting nearby magnetic nuclei, including a metal-bound substrate hydrogen, and for mapping the spin density distribution of the unpaired electron at the active site. the observed hyperfine couplings are assigned via com ... | 2004 | 15611882 |
| desulfovibrio putealis sp. nov., a novel sulfate-reducing bacterium isolated from a deep subsurface aquifer. | a novel sulfate-reducing bacterium was isolated from a well that collected water from a deep aquifer at a depth of 430 m in the paris basin, france. the strain, designated b7-43t, was made up of vibrioid cells that were motile by means of a single polar flagellum. cells contained desulfoviridin. in the presence of sulfate, the following substrates were used as energy and carbon sources: lactate, pyruvate, malate, fumarate, ethanol, butanol, acetate/h2 and glycine. sulfite and thiosulfate were al ... | 2005 | 15653861 |
| epr experiments to elucidate the structure of the ready and unready states of the [nife] hydrogenase of desulfovibrio vulgaris miyazaki f. | isolation and purification of the [nife] hydrogenase of desulfovibrio vulgaris miyazaki f under aerobic conditions leads to a mixture of two states, ni-a (unready) and ni-b (ready). the two states are distinguished by different activation times and different epr spectra. hyscore and endor data and dft calculations show that both states have an exchangeable proton, albeit with a different (1)h hyperfine coupling. this proton is assigned to the bridging ligand between ni and fe. for ni-b, a hydrox ... | 2005 | 15667250 |
| on the relationship between affinity for molecular hydrogen and the physiological directionality of hydrogenases. | the physiological significance of the generic reaction h(2)<-->2[h] is not always clear because hydrogenases may function in the breakdown of molecular hydrogen or in its synthesis or in both directions. fe-hydrogenases have nevertheless been most often associated with proton reduction and nife-hydrogenases with hydrogen oxidation. a re-determination of the k(m) of h(2) oxidation by pyrococcus furiosus nife-hydrogenase-i and by desulfovibrio vulgaris fe-hydrogenase suggests that affinity for hyd ... | 2005 | 15667251 |
| construction of a [nife]-hydrogenase deletion mutant of desulfovibrio vulgaris hildenborough. | a mutant of desulfovibrio vulgaris hildenborough lacking a gene for [nife] hydrogenase was generated. growth studies, performed for the mutant in comparison with the wild-type, showed no strong differences during the exponential growth phase. however, the mutant cells died more rapidly in the stationary growth phase. | 2005 | 15667264 |
| applications of bacterial hydrogenases in waste decontamination, manufacture of novel bionanocatalysts and in sustainable energy. | bacterial hydrogenases have been harnessed to the removal of heavy metals from solution by reduction to less soluble metal species. for pd(ii), its bioreduction results in the deposition of cell-bound pd(0)-nanoparticles that are ferromagnetic and have a high catalytic activity. hydrogenases can also be used synthetically in the production of hydrogen from sugary wastes through breakdown of formate produced by fermentation. the bio-h(2) produced can be used to power an electrical device using a ... | 2005 | 15667270 |
| transcriptional regulation of a hybrid cluster (prismane) protein. | hcp (hybrid-cluster protein) contains two fe/s clusters, one of which is a hybrid [4fe-2s-2o] cluster. despite intensive study, its physiological function has not been reported. the escherichia coli hcp gene is located in a two-gene operon with hcr, which encodes an nadh-dependent hcp reductase. e. coli hcp is detected after anaerobic growth with nitrate or nitrite: possible roles for it in hydroxylamine or nitric oxide reduction have been proposed. to study the regulation and role of hcp, an hc ... | 2005 | 15667305 |
| dehalogenation of chlorinated aromatic compounds using a hybrid bioinorganic catalyst on cells of desulfovibrio desulfuricans. | a novel bioinorganic catalyst was obtained via reduction of pd(ii) to pd0 on to the surface of cells of desulfovibrio desulfuricans at the expense of h2. palladised biomass, supplied with formate or h2 as an electron donor, catalysed the dehalogenation of 2-chlorophenol and polychlorinated biphenyls. in the example of 2,3,4,5-tetrachlorobiphenyl, the bioinorganic catalyst promoted a rate of chloride release of 9.33 +/- 0.17 nmol min(-1) mg (-1) and only approximately 5% of this value was obtaine ... | 2004 | 15672233 |
| structural determinants of protein stabilization by solutes. the important of the hairpin loop in rubredoxins. | despite their high sequence homology, rubredoxins from desulfovibrio gigas and d. desulfuricans are stabilized to very different extents by compatible solutes such as diglycerol phosphate, the major osmolyte in the hyperthermophilic archaeon archaeoglobus fulgidus[lamosa p, burke a, peist r, huber r, liu m y, silva g, rodrigues-pousada c, legall j, maycock c and santos h (2000) appl environ microbiol66, 1974-1979]. the principal structural difference between these two proteins is the absence of ... | 2005 | 15691333 |
| fmn binding and unfolding of desulfovibrio desulfuricans flavodoxin: "hidden" intermediates at low denaturant concentrations. | the flavin mononucleotide (fmn) cofactor in desulfovibrio desulfuricans flavodoxin stays associated with the polypeptide upon guanidine hydrochloride (guhcl) induced unfolding. using isothermal titration calorimetry (itc), we determined the affinity of fmn for the flavodoxin polypeptide as a function of both urea and guhcl concentrations (ph 7, 25 degrees c). the fmn affinity for folded and guhcl-unfolded flavodoxin differs 10-fold, which is in agreement with the difference in thermodynamic stab ... | 2004 | 15698959 |
| synthesis of the h-cluster framework of iron-only hydrogenase. | the metal-sulphur active sites of hydrogenases catalyse hydrogen evolution or uptake at rapid rates. understanding the structure and function of these active sites--through mechanistic studies of hydrogenases, synthetic assemblies and in silico models--will help guide the design of new materials for hydrogen production or uptake. here we report the assembly of the iron-sulphur framework of the active site of iron-only hydrogenase (the h-cluster), and show that it functions as an electrocatalyst ... | 2005 | 15703741 |
| production of antimicrobial substances by bacillus subtilis lfe-1, b. firmus ho-1 and b. licheniformis t6-5 isolated from an oil reservoir in brazil. | forty bacillus strains isolated from a brazilian oil reservoir were tested against each other to select strains producing antimicrobial substances (ams). three strains, bacillus subtilis (lfe-1), bacillus firmus (h2o-1) and bacillus licheniformis (t6-5), were selected due to their ability to inhibit more than 65% of the bacillus strains tested. these three strains were also investigated for their capability to inhibit sulphate-reducing bacteria (srb). furthermore, physiological and biochemical c ... | 2005 | 15715870 |
| a flavo-diiron protein from desulfovibrio vulgaris with oxidase and nitric oxide reductase activities. evidence for an in vivo nitric oxide scavenging function. | a few members of a widespread class of bacterial and archaeal flavo-diiron proteins, dubbed fpras, have been shown to function as either oxidases (dioxygen reductases) or scavenging nitric oxide reductases, but the questions of which of these functions dominates in vivo for a given fpra and whether all fpras function as oxidases or nitric oxide reductases remain to be clarified. to address these questions, an fpra has been characterized from the anaerobic sulfate-reducing bacterium desulfovibrio ... | 2005 | 15736966 |
| combined spectroscopic/computational study of binuclear fe(i)-fe(i) complexes: implications for the fully-reduced active-site cluster of fe-only hydrogenases. | the fe(i)-fe(i) dimer complex [fe2(pdt)(co)4(cn)2][et4n]2 (2), where pdt = 1,3-propane dithiolate, serves as a model of the fully reduced [2fe]h component of the h cluster, which is the active site for catalysis in fe-only hydrogenases (fehases). electronic absorption, magnetic circular dichroism (mcd), and resonance raman (rr) spectroscopies have been employed to characterize both the ground and excited states of 2 as well as those of the related complex fe2(pdt)(co)6 (1). these results have be ... | 2005 | 15762706 |
| electric-field-induced redox potential shifts of tetraheme cytochromes c3 immobilized on self-assembled monolayers: surface-enhanced resonance raman spectroscopy and simulation studies. | the tetraheme protein cytochrome c(3) (cyt-c(3)) from desulfovibrio gigas, immobilized on a self-assembled monolayer (sam) of 11-mercaptoundecanoic acid, is studied by theoretical and spectroscopic methods. molecular dynamics simulations indicate that the protein docks to the negatively charged sam via its lysine-rich domain around the exposed heme iv. complex formation is associated with only little protein structural perturbations. this finding is in line with the resonance raman and surface-e ... | 2005 | 15764652 |
| rubredoxin acts as an electron donor for neelaredoxin in archaeoglobus fulgidus. | archaeoglobus fulgidus neelaredoxin (nlr) is an electron donor:superoxide oxidoreductase. the reaction of superoxide with reduced nlr is almost diffusion-limited, but the overall efficiency for detoxifying superoxide in vivo depends on the rate of reduction of nlr by electron donors. here, we report the purification and characterization of the two type i rubredoxins from a. fulgidus (af0880 and af1349) and show that they act as efficient electron donors for neelaredoxin, in vitro, with a second- ... | 2005 | 15766568 |
| buildup of polyelectrolyte-protein multilayer assemblies on gold electrodes. role of the hydrophobic effect. | the buildup of layer-by-layer assemblies onto gold surfaces from water-soluble charged polyelectrolytes and proteins is examined using quartz crystal microgravimetry (qcm) and electrochemical techniques. polyelectrolytes such as poly(styrenesulfonate) and poly(ester sulfonic acid) (eastman aq-29d polymer) adsorb spontaneously onto gold, contrary to poly(ethyleneimine). from the modification of the gold surface with a thiol and specific adsorption of polymers under polarization conditions, it is ... | 2004 | 15773101 |
| [choice of isolation procedure for endotoxins from the outer membrane of the bacteria desulfovibrio desulfuricans]. | the chemical structure determining properties and biological functions of endotoxins derived from desulfovibrio desulfuricans species has not been recognized, which considerably hinders the choice of an effective extraction procedure of these lipopolysaccharides (lps) from the bacterial outer cell membrane. we aimed at selecting the most effective method of lps isolation from d. desulfuricans in terms of the most efficient extraction solution, the appropriate conditions of isolation and adequate ... | 2004 | 15773506 |
| interaction and electron transfer between the high molecular weight cytochrome and cytochrome c3 from desulfovibrio vulgaris hildenborough: kinetic, microcalorimetric, epr and electrochemical studies. | the complex formation between the tetraheme cytochrome c3 and hexadecaheme high molecular weight cytochrome c (hmc), the structure of which has recently been resolved, has been characterized by cross-linking experiments, epr, electrochemistry and kinetic analysis, and some key parameters of the interaction were determined. the analysis of electron transfer between [fe] hydrogenase, cytochrome c3 and hmc demonstrates a redox-shuttling role of cytochrome c3 in the pathway from hydrogenase to hmc, ... | 2005 | 15780995 |
| structural differences between the ready and unready oxidized states of [nife] hydrogenases. | [nife] hydrogenases catalyze the reversible heterolytic cleavage of molecular hydrogen. several oxidized, inactive states of these enzymes are known that are distinguishable by their very different activation properties. so far, the structural basis for this difference has not been understood because of lack of relevant crystallographic data. here, we present the crystal structure of the ready ni-b state of desulfovibrio fructosovorans [nife] hydrogenase and show it to have a putative mu-hydroxo ... | 2005 | 15803334 |
| structure of s35c flavodoxin mutant from desulfovibrio vulgaris in the semiquinone state. | the crystallographic structure of an engineered flavodoxin mutant from desulfovibrio vulgaris has been analysed. site-directed mutagenesis was used to substitute serine 35 with a cysteine to provide a possible covalent linkage. the crystal structure of the semiquinone form of this mutant is similar to the corresponding oxidation state of the wild-type flavodoxin. analysis of the structural changes reveals the interaction between n(5)h of the flavin and the carbonyl o atom of gly61 to be critical ... | 2005 | 15805604 |
| bioinformatics, genomics and evolution of non-flagellar type-iii secretion systems: a darwinian perspective. | we review the biology of non-flagellar type-iii secretion systems from a darwinian perspective, highlighting the themes of evolution, conservation, variation and decay. the presence of these systems in environmental organisms such as myxococcus, desulfovibrio and verrucomicrobium hints at roles beyond virulence. we review newly discovered sequence homologies (e.g., yopn/tyea and sepl). we discuss synapomorphies that might be useful in formulating a taxonomy of type-iii secretion. the problem of ... | 2005 | 15808742 |
| the hydrogenases of geobacter sulfurreducens: a comparative genomic perspective. | the hydrogenase content of the genome of geobacter sulfurreducens, a member of the family geobacteraceae within the delta-subdivision of the proteobacteria, was examined and found to be distinct from that of desulfovibrio species, another family of delta-proteobacteria on which extensive research concerning hydrogen metabolism has been conducted. four [nife]-hydrogenases are encoded in the g. sulfurreducens genome: two periplasmically oriented, membrane-bound hydrogenases, hya and hyb, and two c ... | 2005 | 15817791 |
| analysis of bacterial diversity in acidic pond water and compost after treatment of artificial acid mine drainage for metal removal. | the microbial population of a sludge amended leaf compost material utilized for treatment of artificial acid mine drainage was studied by culture-independent molecular methods. iron-rich and sulfurous wastewater (artificial acid mine drainage) was circulated through a column bioreactor for 16 months. after 12 months the column was inoculated with a mixed culture from an acidic pond receiving acid mine drainage from a tailings impoundment at a decommissioned site in kristineberg, north sweden. hy ... | 2005 | 15818559 |
| reduction of cr(vi) by immobilized cells of desulfovibrio vulgaris ncimb 8303 and microbacterium sp. ncimb 13776. | hexavalent chromium, a carcinogen and mutagen, can be reduced to cr(iii) by desulfovibrio vulgaris ncimb 8303 and microbacterium sp. ncimb 13776. this study examined cr(vi) reduction by immobilized cells of the two strains in a common solution matrix using various entrapment matrices. chitosan and pva-borate beads did not retain integrity and supported low or no reduction of cr(vi) by the cells. a commercial preparation (lentikats) was stable but also did not support cr(vi) reduction. k-carragee ... | 2005 | 15818565 |
| oxygen tolerance of the h2-sensing [nife] hydrogenase from ralstonia eutropha h16 is based on limited access of oxygen to the active site. | hydrogenases, abundant proteins in the microbial world, catalyze cleavage of h2 into protons and electrons or the evolution of h2 by proton reduction. hydrogen metabolism predominantly occurs in anoxic environments mediated by hydrogenases, which are sensitive to inhibition by oxygen. those microorganisms, which thrive in oxic habitats, contain hydrogenases that operate in the presence of oxygen. we have selected the h2-sensing regulatory [nife] hydrogenase of ralstonia eutropha h16 to investiga ... | 2005 | 15849358 |
| x-ray crystal structures of moorella thermoacetica fpra. novel diiron site structure and mechanistic insights into a scavenging nitric oxide reductase. | several members of a widespread class of bacterial and archaeal metalloflavoproteins, called fpra, likely function as scavenging nitric oxide reductases (s-nors). however, the only published x-ray crystal structure of an fpra is for a protein characterized as a rubredoxin:dioxygen oxidoreductase (roo) from desulfovibrio gigas. therefore, the crystal structure of moorella thermoacetica fpra, which has been established to function as an s-nor, was solved in three different states: as isolated, red ... | 2005 | 15850383 |
| binding of ligands originates small perturbations on the microscopic thermodynamic properties of a multicentre redox protein. | nmr and visible spectroscopy coupled to redox measurements were used to determine the equilibrium thermodynamic properties of the four haems in cytochrome c3 under conditions in which the protein was bound to ligands, the small anion phosphate and the protein rubredoxin with the iron in the active site replaced by zinc. comparison of these results with data for the isolated cytochrome shows that binding of ligands causes only small changes in the reduction potentials of the haems and their pairw ... | 2005 | 15853810 |
| desulfovibrio brasiliensis sp. nov., a moderate halophilic sulfate-reducing bacterium from lagoa vermelha (brazil) mediating dolomite formation. | a novel halotolerant sulfate-reducing bacterium, desulfovibrio brasiliensis strain lvform1, was isolated from sediments of a dolomite-forming hypersaline coastal lagoon, lagoa vermelha, in the state of rio de janeiro, brazil. the cells are vibrio-shaped and 0.30 to 0.45 microm by 1.0 to 3.5 microm in size. these bacteria mediate the precipitation of dolomite [camg(co3)2] in culture experiments. the strain was identified as a member of the genus desulfovibrio in the delta-subclass of the proteoba ... | 2005 | 15856133 |
| nested pcr-denaturing gradient gel electrophoresis approach to determine the diversity of sulfate-reducing bacteria in complex microbial communities. | here, we describe a three-step nested-pcr-denaturing gradient gel electrophoresis (dgge) strategy to detect sulfate-reducing bacteria (srb) in complex microbial communities from industrial bioreactors. in the first step, the nearly complete 16s rrna gene was amplified using bacterial primers. subsequently, this product was used as a template in a second pcr with group-specific srb primers. a third round of amplification was conducted to obtain fragments suitable for dgge. the largest number of b ... | 2005 | 15870318 |
| reoxidation of reduced uranium with iron(iii) (hydr)oxides under sulfate-reducing conditions. | in cultures of desulfovibrio desulfuricans 620 the effects of iron(iii) (hydr)oxides (hematite, goethite, and ferrihydrite) on microbial reduction and reoxidation of uranium (u) were evaluated under lactate-limited sulfate-reducing conditions. with lactate present, g20 reduced u(vi) in both 1,4-piperazinediethanesulfonate (pipes) and bicarbonate buffer. once lactate was depleted, however, microbially reduced u served as an electron donor to reduce fe(iii) present in iron(iii) (hydr)oxides. with ... | 2005 | 15871237 |
| effect of inorganic phosphate on fmn binding and loop flexibility in desulfovibrio desulfuricans apo-flavodoxin. | the complex between flavin mononucleotide (fmn) and apo-flavodoxin is dominated by isoalloxazine-stacking interactions and 5'-phosphate hydrogen bonds. we show here that fmn binding to desulfovibrio desulfuricans apo-flavodoxin is faster and the affinity is higher in the presence of inorganic phosphate as compared to in its absence (i=110 mm, ph 7, 20 degrees c). the transition-state of complex formation was investigated by phi-value analysis using trp60ala and tyr98ala apo-flavodoxin variants. ... | 2005 | 15876370 |
| reductive dechlorination of tetrachloroethene to trans-dichloroethene and cis-dichloroethene by pcb-dechlorinating bacterium df-1. | polychlorinated biphenyls (pcbs) and chlorinated ethenes (ces) are known to pollute sediment, soil, and groundwater. the anaerobic dechlorination of these compounds is an integral part of their biodegradation in polluted environments. we report for the first time the dechlorination of tetrachloroethene (pce) and trichloroethene (tce) by bacterium df-1. this pcb and chlorobenzene dechlorinating bacterium dechlorinated pce to tce, which was then converted into trans-1,2-dichloroethene (trans-dce) ... | 2005 | 15884359 |
| high-resolution crystal structures of desulfovibrio vulgaris (hildenborough) nigerythrin: facile, redox-dependent iron movement, domain interface variability, and peroxidase activity in the rubrerythrins. | high-resolution crystal structures of desulfovibrio vulgaris nigerythrin (dvngr), a member of the rubrerythrin (rbr) family, demonstrate an approximately 2-a movement of one iron (fe1) of the diiron site from a carboxylate to a histidine ligand upon conversion of the mixed-valent ([fe2(ii),fe1(iii)]) to diferrous states, even at cryogenic temperatures. this glu<-->his ligand "toggling" of one iron, which also occurs in dvrbr, thus, appears to be a characteristic feature of rbr-type diiron sites. ... | 2005 | 15895271 |
| biodegradation of cyclic nitramines by tropical marine sediment bacteria. | undersea deposition of unexploded ordnance (uxo) constitutes a potential source of contamination of marine environments by hexahydro-1,3,5-trinitro-1,3,5-triazine (rdx) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (hmx). the goal of the present study was to determine microbial degradation of rdx and hmx in a tropical marine sediment sampled from a coastal uxo field in the region of oahu island in hawaii. sediment mixed cultures growing in marine broth 2216 (21 degrees c) anaerobically mi ... | 2005 | 15915354 |
| anaerobic purification and crystallization to improve the crystal quality: ferredoxin ii from desulfovibrio gigas. | sulfate-reducing bacteria (srb), which are strict anaerobes, contain an electron-transfer chain from pyridine nucleotides to molecular oxygen. this unique enzymatic equipment allows the bacterium to produce atp when exposed to air from the degradation of internal reserves of polyglucose. ferredoxin ii (fd ii) is a small electron-transfer protein isolated from the strict anaerobic sulfate-reducing bacterium desulfovibrio gigas. the protein contains 58 amino acids and an iron-sulfur cluster. the c ... | 2005 | 15930639 |
| characterization of sulfate reducing bacteria isolated from cooling towers. | in this study, the occurrence and metabolic capacities of sulfate reducing bacteria (srb) were studied in 36 water samples taken from cooling towers of 30 different buildings, such as hotels and business centres in istanbul. srb were present in 14 cooling towers out of 30 (46.6%) buildings and while the lowest concentration of srb was 10 cells/ml, the highest concentration was determined as 10(4) cells/ml. after the distribution of srb within cooling towers was determined, several strains of srb ... | 2005 | 15931988 |
| in vitro and in vivo sulfate reduction in the gut contents of the termite mastotermes darwiniensis and the rose-chafer pachnoda marginata. | sulfate-reducing bacteria (srb) from termites have been assigned to the genus desulfovibrio. desulfovibrio intestinalis lives in the gut of the australian termite mastotermes darwiniensis. for the first time we were able to enrich and identify a sulfate-reducing bacterium from the gut of the rose-chafer pachnoda marginata, which showed the highest 16s rdna sequence identity (93%) to desulfovibrio intestinalis and desulfovibrio strain stl1. compared to mastotermes darwiniensis (1x10(7) cells of s ... | 2005 | 15942866 |
| sulphate respiration from hydrogen in desulfovibrio bacteria: a structural biology overview. | sulphate-reducing organisms are widespread in anaerobic enviroments, including the gastrointestinal tract of man and other animals. the study of these bacteria has attracted much attention over the years, due also to the fact that they can have important implications in industry (in biocorrosion and souring of oil and gas deposits), health (in inflamatory bowel diseases) and the environment (bioremediation). the characterization of the various components of the electron transport chain associate ... | 2004 | 15950057 |
| theoretical calculations on hydrogenase kinetics: explanation of the lag phase and the enzyme concentration dependence of the activity of hydrogenase uptake. | two models of the hydrogenase reaction cycle were investigated by means of theoretical calculations and model simulations. the first model is the widely accepted triangular hydrogenase reaction cycle with minor modifications; the second is a modified triangular model, where we have introduced an autocatalytic step into the reaction cycle. both models include a one-step activation reaction. the theoretical calculations and model simulations corroborate the assumed autocatalytic reaction step conc ... | 2005 | 15951384 |
| development of methods for the detection and quantification of 7alpha-dehydroxylating clostridia, desulfovibrio vulgaris, methanobrevibacter smithii, and lactobacillus plantarum in human feces. | mounting evidence suggests a relationship between bacterial metabolism of certain dietary and endogenous factors and the development of colorectal cancer. deoxycholic acid (dca) is a well studied co-carcinogen and bio-transformation product of 7alpha-dehydroxylating clostridia. h2s is a cytotoxic metabolite produced primarily by sulfate-reducing bacteria (srb). the production of methane indicates low levels of active srb. lactic acid bacteria (lab) have received attention recently due to their p ... | 2005 | 15963794 |
| aerobic organic carbon mineralization by sulfate-reducing bacteria in the oxygen-saturated photic zone of a hypersaline microbial mat. | the sulfate-reducing bacterium strain srb d2 isolated from the photic zone of a hypersaline microbial mat, from lake chiprana, ne spain, respired pyruvate, alanine, and alpha-ketoglutarate but not formate, lactate, malate, succinate, and serine at significant rates under fully oxic conditions. dehydrogenase enzymes of only the former substrates are likely oxygen-tolerant as all substrates supported anaerobic sulfate reduction. no indications were found, however, that aerobic respiration supporte ... | 2005 | 15965719 |
| nitrate reduction by desulfovibrio desulfuricans: a periplasmic nitrate reductase system that lacks napb, but includes a unique tetraheme c-type cytochrome, napm. | many sulphate reducing bacteria can also reduce nitrite, but relatively few isolates are known to reduce nitrate. although nitrate reductase genes are absent from desulfovibrio vulgaris strain hildenborough, for which the complete genome sequence has been reported, a single subunit periplasmic nitrate reductase, napa, was purified from desulfovibrio desulfuricans strain 27774, and the structural gene was cloned and sequenced. chromosome walking methods have now been used to determine the complet ... | 2005 | 15972253 |
| horizontal transfer of two operons coding for hydrogenases between bacteria and archaea. | using a phylogenetic approach, we discovered three putative horizontal transfers between bacterial and archaeal species involving large clusters of genes. one transfer involves an operon of 13 genes, called mbx, which probably was transferred into the genome of thermotoga maritima from a species belonging or close to the pyrococcus genus. the two others implied an operon of six genes, called ech, transferred independently to the genomes of thermoanaerobacter tengcongensis and desulfovibrio gigas ... | 2005 | 15983865 |
| synthesis, characterization, biocide and toxicological activities of di-n-butyl- and diphenyl-tin(iv)-salicyliden-beta-amino alcohol derivatives. | the one pot reaction of salicylaldehyde 1, beta-amino alcohols 2a-2c, and di-n-butyltin(iv) oxide 3a or diphenyltin(iv) oxide 3b produced five diorganotin(iv) compounds, 4a-4c, 5a, and 5c, in good yields. all compounds were characterized by ir, (1)h, (13)c, and (119)sn nmr spectroscopy, and elemental analysis; furthermore, compounds 4b, 4c, 5a, and 5c were characterized by x-ray diffraction analysis. after the structural characterization, all of the compounds were tested in vitro against bacillu ... | 2005 | 16022535 |
| response of the anaerobe desulfovibrio vulgaris hildenborough to oxidative conditions: proteome and transcript analysis. | the method of two-dimensional protein gel electrophoresis was used to evaluate the changes at the proteins level following oxygen exposure of the anaerobic sulfate-reducing bacterium desulfovibrio vulgaris hildenborough. fifty-seven proteins showed significant differential expression. the cellular concentration of 35 proteins decreased while that of nineteen increased as a specific consequence of oxidative conditions. the proteins that were less abundant belonged to various functional categories ... | 2006 | 16040186 |
| structure-function relationships in mitochondrial complex i of the strictly aerobic yeast yarrowia lipolytica. | the obligate aerobic yeast yarrowia lipolytica has been established as a powerful model system for the analysis of mitochondrial complex i. using a combination of genomic and proteomic approaches, a total of 37 subunits was identified. several of the accessory subunits are predicted to be stmd (single transmembrane domain) proteins. site-directed mutagenesis of y. lipolytica complex i has provided strong evidence that a significant part of the ubiquinone reducing catalytic core resides in the 49 ... | 2005 | 16042611 |
| biochemical differentiation and comparison of desulfovibrio species and other phenotypically similar genera. | seventeen human clinical isolates representing four species of desulfovibrio were characterized using 16s rrna gene sequences and tests for catalase, indole, nitrate, bile, urease, formate-fumarate stimulation, desulfoviridin, motility, and hydrogen sulfide production, plus susceptibility to antimicrobial agents. eighty additional strains representing 10 phenotypically similar genera (bilophila, selenomonas, capnocytophaga, campylobacter, bacteroides, sutterella, anaerobiospirillum, dialister, v ... | 2005 | 16081948 |
| fe(3+)-eta(2)-peroxo species in superoxide reductase from treponema pallidum. comparison with desulfoarculus baarsii. | superoxide reductases (sors) are superoxide (o2-)-detoxifying enzymes that catalyse the reduction of o2- into hydrogen peroxide. three different classes of sor have been reported on the basis of the presence or not of an additional n-terminal domain. they all share a similar active site, with an unusual non-heme fe atom coordinated by four equatorial histidines and one axial cysteine residues. crucial catalytic reaction intermediates of sor are purported to be fe(3+)-(hydro)peroxo species. using ... | 2006 | 16084640 |
| structure and topology of microbial communities in the major gut compartments of melolontha melolontha larvae (coleoptera: scarabaeidae). | physicochemical gut conditions and the composition and topology of the intestinal microbiota in the major gut compartments of the root-feeding larva of the european cockchafer (melolontha melolontha) were studied. axial and radial profiles of ph, o2, h2, and redox potential were measured with microsensors. terminal restriction fragment length polymorphism (t-rflp) analysis of bacterial 16s rrna genes in midgut samples of individual larvae revealed a simple but variable and probably nonspecific c ... | 2005 | 16085849 |
| cadmium accumulation and dna homology with metal resistance genes in sulfate-reducing bacteria. | cadmium resistance (0.1 to 1.0 mm) was studied in four pure and one mixed culture of sulfate-reducing bacteria (srb). the growth of the bacteria was monitored with respect to carbon source (lactate) oxidation and sulfate reduction in the presence of various concentrations of cadmium chloride. two strains desulfovibrio desulfuricans dsm 1926 and desulfococcus multivorans dsm 2059 showed the highest resistance to cadmium (0.5 mm). transmission electron microscopy of the two strains showed intracel ... | 2005 | 16085855 |