Desulfobotulus gen. nov.

Abstract

De.sul.fo.bo' tu.lus . L pref. de from; L. n. sulfur sulfur; M.L. masc. n. botulus sausage; M.L. masc. n. Desulfobotulus a sausage‐shaped sulfate reducer. Desulfobacterota / Desulfobacteria / Desulfobacterales / Desulfobacteraceae / Desulfobotulus Vibrio‐shaped cells, 1.5 × 3–5.5 μm . Occur singly or in pairs. Sigmoid or spirilloid cells sometimes occur. Spore formation is not observed. Gram negative. The type species is motile. Strict anaerobe with a respiratory type of metabolism. Chemoorganotrophic , using butyrate, 2‐methylbutyrate, higher fatty acids up to 18 carbon atoms, lactate, and pyruvate as electron donors and as carbon sources; carbon sources are incompletely oxidized to acetate as an end product. Sulfate and sulfite serve as terminal electron acceptors and are reduced to H 2 S. Thiosulfate, sulfur, fumarate, and nitrate are not used as terminal electron acceptors. Growth in the absence of an external electron acceptor is only possible with pyruvate . Optimal temperature, 34°C. Anoxic medium, with sulfide as a reductant, is necessary for growth. Vitamins are not required. Cells contain cytochromes of the b ‐ and c ‐type. Storage granules of poly‐β‐hydroxybutyrate occur. Desulfobotulus species are widespread in freshwater mud, but might occur in brackish or marine sediments as well. The mol % G + C of the DNA is : 53. Type species : Desulfobotulus sapovorans comb. nov . ( Desulfovibrio sapovorans Widdel 1981, 382.)