Thiobacillus


Thiobacillus is a genus of Gram-negative Betaproteobacteria. Thiobacilus thioparus is the type species of the genus, and the type strain thereof is the StarkeyT strain, isolated by Robert Starkey in the 1930s from a field at Rutgers University in the United States of America. While over 30 "species" have been named in this genus since it was defined by Martinus Beijerinck in 1904,, most names were never validly or effectively published. The remainder were either reclassified into Paracoccus, Starkeya ; Sulfuriferula, Annwoodia, Thiomonas ; Halothiobacillus, Guyparkeria, or Thermithiobacillus or Acidithiobacillus. The very loosely defined "species" Thiobacillus trautweinii was where sulfur oxidising heterotrophs and chemolithoheterotrophs were assigned in the 1910-1960s era, most of which were probably Pseudomonas species. Many species named in this genus were never deposited in service collections and have been lost.
All species are obligate autotrophs 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 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.