All species are obligate autotrophs[1][2][3] (using the transaldolase form of the Calvin-Benson-Bassham cycle[4]) using elementary sulfur, thiosulfate, or polythionates as energy sources - the former Thiobacillus aquaesulis can grow weakly on complex media as a heterotroph, but has been reclassified to Annwoodia aquaesulis. Some strains (E6 and Tk-m) of the type species Thiobacillus thioparus can use the sulfur from dimethylsulfide, dimethyldisulfide, or carbon disulfide to support autotrophic growth - they oxidise the carbon from these species into carbon dioxide and assimilate it. Sulfur oxidation is achieved via the Kelly-Trudinger pathway.
Reclassifications
As a result of 16S ribosomal RNA sequence analysis, many members of Thiobacillus have been reassigned.[5][4][6]
^ abBeijerinck MW (1904). "Ueber die Bakterien, welche sich im Dunkeln mit Kohlensäure als Kohlenstoffquelle ernähren können". Centralbl Bakteriol Parasitenkd Infektionskr Hyg Abt II. 11: 592–599.
^Kelly DP; WoodAP (1993). "Reclassification of Thiobacillus thyasiris as Thiomicrospira thyasirae, new combination, an organism exhibiting pleomorphism in response to environmental conditions". Archives of Microbiology. 159: 45–47. doi:10.1007/BF00244262. S2CID23406498.