Desulfitobacterium: A genus of anaerobic, gram-positive bacteria in the family Peptococcaceae, that reductively dechlorinates CHLOROPHENOLS.Tetrachloroethylene: A chlorinated hydrocarbon used as an industrial solvent and cooling liquid in electrical transformers. It is a potential carcinogen.Chlorophenols: Phenols substituted with one or more chlorine atoms in any position.Peptococcaceae: A family of bacteria found in the mouth and intestinal and respiratory tracts of man and other animals as well as in the human female urogenital tract. Its organisms are also found in soil and on cereal grains.Pentachlorophenol: An insecticide and herbicide that has also been used as a wood preservative. Pentachlorphenol is a widespread environmental pollutant. Both chronic and acute pentachlorophenol poisoning are medical concerns. The range of its biological actions is still being actively explored, but it is clearly a potent enzyme inhibitor and has been used as such as an experimental tool.Oxidoreductases, O-Demethylating: Drug metabolizing enzymes which oxidize methyl ethers. Usually found in liver microsomes.Corrinoids: Cyclic TETRAPYRROLES based on the corrin skeleton.Bacteria, AnaerobicTungsten Compounds: Inorganic compounds that contain tungsten as an integral part of the molecule.Clostridium bifermentans: A species of gram-positive bacteria in the family Clostridiaceae that ferments both CARBOHYDRATES and AMINO ACIDS.Dichloroethylenes: Toxic chlorinated unsaturated hydrocarbons. Include both the 1,1- and 1,2-dichloro isomers. Both isomers are toxic, but 1,1-dichloroethylene is the more potent CNS depressant and hepatotoxin. It is used in the manufacture of thermoplastic polymers.Humic Substances: Organic matter in a state of advanced decay, after passing through the stages of COMPOST and PEAT and before becoming lignite (COAL). It is composed of a heterogenous mixture of compounds including phenolic radicals and acids that polymerize and are not easily separated nor analyzed. (E.A. Ghabbour & G. Davies, eds. Humic Substances, 2001).Halogens: A family of nonmetallic, generally electronegative, elements that form group 17 (formerly group VIIa) of the periodic table.Biodegradation, Environmental: Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.Gram-Positive Rods: A large group of rod-shaped bacteria that retains the crystal violet stain when treated by Gram's method.Ethylene Dichlorides: Toxic, chlorinated, saturated hydrocarbons. Include both the 1,1- and 1,2-dichloro isomers. The latter is considerably more toxic. It has a sweet taste, ethereal odor and has been used as a fumigant and intoxicant among sniffers. Has many household and industrial uses.Chlorine: A greenish-yellow, diatomic gas that is a member of the halogen family of elements. It has the atomic symbol Cl, atomic number 17, and atomic weight 70.906. It is a powerful irritant that can cause fatal pulmonary edema. Chlorine is used in manufacturing, as a reagent in synthetic chemistry, for water purification, and in the production of chlorinated lime, which is used in fabric bleaching.Gram-Positive Bacteria: Bacteria which retain the crystal violet stain when treated by Gram's method.Sulfonic Acids: Inorganic or organic oxy acids of sulfur which contain the RSO2(OH) radical.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)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.Anthraquinones: Compounds based on ANTHRACENES which contain two KETONES in any position. Substitutions can be in any position except on the ketone groups.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).Vitamin B 12: A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. INTRINSIC FACTOR is important for the assimilation of vitamin B 12.Sulfites: Inorganic salts of sulfurous acid.DNA, Ribosomal: DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.