Thiobacillus

Abstract

Thi.o.ba.cil'lus. Gr. neut. n. theîon, sulfur, brimstone; L. masc. n. bacillus, a short rod, a short wand; N.L. masc. n. Thiobacillus, sulfur rodlet.

Proteobacteria / Betaproteobacteria / Nitrosomonadales / Thiobacillaceae / Thiobacillus

Cells are short rods. Cytochrome c oxidase‐positive and catalase‐positive when grown on thiosulfate. Gram‐stain‐negative. Endospores, exospores, and cysts are not produced. Metabolically obligate chemolithoautotrophs, supported by reduced sulfur species and elementary sulfur, and some methylated sulfur compounds. Genes encoding Form IAc, Form IAq, and Form II d‐ribulose 1,5‐bisphosphate carboxylase/oxygenases (RuBisCO) are present in the genomes. Carboxysomes are produced in some species and are repressed at high CO2 partial pressures. Volutin (polyphosphate) granules formed in most species. Produce tetrathionate as a detectable intermediate of thiosulfate oxidation. Obligately respiratory, with molecular oxygen and nitrate the only known terminal electron acceptors, with the latter only used in some species. Mesophilic, growing optimally at 25–32°C, and one psychrophilic species capable of growth down to −2°C. The major respiratory quinone is ubiquinone‐8 (UQ‐8). Dominant fatty acids are C16:0, C16:1, C15:0, and C17:1.

DNA G + C content (mol%): 61.5–66.0.

Type species: Thiobacillus thioparus Beijerinck 1904b, 153AL.