Sulfobacillus

Abstract

Sul.fo.ba.cil'lus. L. neut. n.sulfursulfur; L. n.bacillussmall rod; N.L. masc. n.Sulfobacillussmall sulfur‐oxidizing rod.Firmicutes / “Clostridia” / Clostridiales / incertae Sedis ‐ Family VI / SulfobacillusStraight rods, 0.5–0.8 µm in diameter by 3.0–5.0 µm in length. Terminal or subterminal ovoid or sphericalendospores. In some strains, the sporangium is swollen. Gram‐stain‐positive. Strains are generallynonmotile;a few strains may be motile.Colonies are not pigmented.Mesophilic or slightly thermophilicwith optimum growth temperatures between about 40 and 55 °C; the temperature range for growth is between 20 and 60 °C.Acidophilic, the pH range for growth is from about 1.5 to 5.5; the optimum is pH 1.9–2.4.Menaquinone‐7is the predominant respiratory quinone. Fatty acids are primarilyiso‐ andanteiso‐branched; straight‐chain fatty acids are also present. ω‐Cyclohexane or ω‐cycloheptane fatty acids are the major components of some strains.Aerobicwith a strictly respiratory type of metabolism; some strains grow underanaerobicconditions with ferric iron as electron acceptor. Species aremixotrophic, with limitedautotrophic and chemoorganotrophic growth. Mixotrophic growth occurs on Fe2+, S0, S2O32−, S4O62−, and sulfide minerals in the presence of yeast extract or single organic compounds. Yeast extract and a few sugars and organic acids are used as sole carbon and energy sources. Strains require yeast extract for growth. Found in acidicsoils and water of geothermal areas,mineral deposits,and ores.DNA G+C content(mol%): 47–57 (Tm).Type species:Sulfobacillus thermosulfidooxidansGolovacheva and Karavaiko 1991, 179VP.