Desulfovibrio: A genus of gram-negative, anaerobic, rod-shaped bacteria capable of reducing sulfur compounds to hydrogen sulfide. Organisms are isolated from anaerobic mud of fresh and salt water, animal intestines, manure, and feces.Desulfovibrio vulgaris: A species of gram-negative, anaerobic, rod-shaped bacteria isolated from soil, animal intestines and feces, and fresh and salt water.Desulfovibrio desulfuricans: The type species of gram-negative, anaerobic bacteria of the genus DESULFOVIBRIO. It is found in FRESHWATER; SOIL, and in marine or brackish water.Desulfovibrio gigas: A species of gram-negative, anaerobic, spiral-shaped bacteria originally isolated from a saltwater pond in France. It contains a well-characterized metabolic pathway that enables it to survive transient contacts with OXYGEN.Desulfovibrio africanus: A species of gram-negative, anaerobic, sigmoid-shaped bacteria isolated from salt and freshwater in Africa.Sulfates: Inorganic salts of sulfuric acid.Hydrogenase: An enzyme found in bacteria. It catalyzes the reduction of FERREDOXIN and other substances in the presence of molecular hydrogen and is involved in the electron transport of bacterial photosynthesis.Rubredoxins: A class of iron-sulfur proteins that contains one iron coordinated to the sulfur atom of four cysteine residues. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Hydrogensulfite Reductase: An enzyme found primarily in SULFUR-REDUCING BACTERIA where it plays an important role in the anaerobic carbon oxidation pathway.Flavodoxin: A low-molecular-weight (16,000) iron-free flavoprotein containing one molecule of flavin mononucleotide (FMN) and isolated from bacteria grown on an iron-deficient medium. It can replace ferredoxin in all the electron-transfer functions in which the latter is known to serve in bacterial cells.Sulfur-Reducing Bacteria: A group of gram-negative, anaerobic bacteria that is able to oxidize acetate completely to carbon dioxide using elemental sulfur as the electron acceptor.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Ferredoxins: Iron-containing proteins that transfer electrons, usually at a low potential, to flavoproteins; the iron is not present as in heme. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Cytochrome c Group: A group of cytochromes with covalent thioether linkages between either or both of the vinyl side chains of protoheme and the protein. (Enzyme Nomenclature, 1992, p539)Oxidoreductases Acting on Sulfur Group Donors: Oxidoreductases with specificity for oxidation or reduction of SULFUR COMPOUNDS.Hemerythrin: A non-heme iron protein consisting of eight apparently identical subunits each containing 2 iron atoms. It binds one molecule of oxygen per pair of iron atoms and functions as a respiratory protein.Thiosulfates: Inorganic salts of thiosulfuric acid possessing the general formula R2S2O3.Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Deltaproteobacteria: A group of PROTEOBACTERIA represented by morphologically diverse, anaerobic sulfidogens. Some members of this group are considered bacterial predators, having bacteriolytic properties.Spectroscopy, Mossbauer: A spectroscopic technique which uses the Mossbauer effect (inelastic scattering of gamma radiation resulting from interaction with heavy nuclei) to monitor the small variations in the interaction between an atomic nucleus and its environment. Such variations may be induced by changes in temperature, pressure, chemical state, molecular conformation, molecular interaction, or physical site. It is particularly useful for studies of structure-activity relationship in metalloproteins, mobility of heavy metals, and the state of whole tissue and cell membranes.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Iron-Sulfur Proteins: A group of proteins possessing only the iron-sulfur complex as the prosthetic group. These proteins participate in all major pathways of electron transport: photosynthesis, respiration, hydroxylation and bacterial hydrogen and nitrogen fixation.Sulfites: Inorganic salts of sulfurous acid.Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Sulfur Acids: Inorganic or organic acids that contain sulfur as an integral part of the molecule.Heme: The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.Pyruvate Synthase: A ferredoxin-containing enzyme that catalyzes the COENZYME A-dependent oxidative decarboxylation of PYRUVATE to acetyl-COENZYME A and CARBON DIOXIDE.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Geologic Sediments: A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)Flavin Mononucleotide: A coenzyme for a number of oxidative enzymes including NADH DEHYDROGENASE. It is the principal form in which RIBOFLAVIN is found in cells and tissues.Desulfovibrionaceae Infections: Infections with bacteria of the family Desulfovibrionaceae.Sulfur: An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.Uranium: Uranium. A radioactive element of the actinide series of metals. It has an atomic symbol U, atomic number 92, and atomic weight 238.03. U-235 is used as the fissionable fuel in nuclear weapons and as fuel in nuclear power reactors.DNA, Ribosomal: DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.Viologens: A group of dipyridinium chloride derivatives that are used as oxidation-reduction indicators. The general formula is 1,1'-di-R-4,4'-bipyridinium chloride, where R = methyl, ethyl, benzyl or, betaine.Cytochromes a1: A subclass of heme a containing cytochromes have a reduced alpha-band absorption of 587-592 nm. They are primarily found in microorganisms.Veillonellaceae: A family of gram-negative bacteria, in the phylum FIRMICUTES.Iron: A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Nickel: A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.Formate Dehydrogenases: Flavoproteins that catalyze reversibly the reduction of carbon dioxide to formate. Many compounds can act as acceptors, but the only physiologically active acceptor is NAD. The enzymes are active in the fermentation of sugars and other compounds to carbon dioxide and are the key enzymes in obtaining energy when bacteria are grown on formate as the main carbon source. They have been purified from bovine blood. EC 1.2.1.2.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)Sulfides: Chemical groups containing the covalent sulfur bonds -S-. The sulfur atom can be bound to inorganic or organic moieties.Bacterial Proteins: Proteins found in any species of bacterium.Spectrum Analysis: The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Tungsten: Tungsten. A metallic element with the atomic symbol W, atomic number 74, and atomic weight 183.85. It is used in many manufacturing applications, including increasing the hardness, toughness, and tensile strength of steel; manufacture of filaments for incandescent light bulbs; and in contact points for automotive and electrical apparatus.Genes, rRNA: Genes, found in both prokaryotes and eukaryotes, which are transcribed to produce the RNA which is incorporated into RIBOSOMES. Prokaryotic rRNA genes are usually found in OPERONS dispersed throughout the GENOME, whereas eukaryotic rRNA genes are clustered, multicistronic transcriptional units.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.Electrochemistry: The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.Molybdenum: A metallic element with the atomic symbol Mo, atomic number 42, and atomic weight 95.94. It is an essential trace element, being a component of the enzymes xanthine oxidase, aldehyde oxidase, and nitrate reductase. (From Dorland, 27th ed)