D esulfobotulus

Abstract

Abstract De.sul.fo.bo'tu.lus. L pref. de from; L. neut. n. sulfur sulfur; L. masc. n. botulus sausage; N.L. masc. n. Desulfobotulus, a sausage‐shaped sulfate reducer. Desulfobacterota / Desulfobacteria / Desulfobacterales / Desulforegulaceae / Desulfobotulus Vibrio‐shaped cells, 1.0–1.5 µm × 3–6.0 µm. Occur singly or in pairs. Sigmoid or spirilloid cells sometimes occur. Spore formation is not observed. Gram‐stain‐negative. Described species are motile. Strict anaerobe with a respiratory or fermentative type of metabolism. Chemoorganoheterotrophs, using fatty acids and pyruvate as electron donors and as carbon sources; growth substrates are incompletely oxidized to acetate. Sulfate and sulfite serve as terminal electron acceptors and are reduced to H 2 S. Growth in the absence of an external electron acceptor is only possible with pyruvate. Mesophilic, optimal temperature 32–34°C. Genus contains one neutrophilic and one haloalkaliphilic species. The haloalkaliphile can use thiosulfate as electron acceptor in addition to sulfate and sulfite. 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‐hydroxyalkanoate occur. Desulfobotulus species are widespread in anoxic freshwater mud, but occur in brackish, marine or hypersaline sediments as well. DNA G + C content (mol %) : 50.8–53.5 (genome). Type species : Desulfobotulus sapovorans (Widdel 1981) Kuever, Rainey and Widdel 2009, 923 VP (Effective publication: Kuever Rainey and Widdel 2005c, 971; basonym Desulfovibrio sapovorans Widdel 1981, 382).