Genomic and Physiological Comparisons Between Heterotrophic Thiobacilli and Acidiphilium cryptum, Thiobacillus versutus sp. nov., and Thiobacillus acidophilus nom. rev.

Abstract

Acidiphilium cryptum grows in yeast extract media with or without elemental sulfur. The growth rate and the cell yield are not changed by the presence of sulfur, but the pH of the medium drops slightly when sulfur is present, presumably because of gratuitous sulfur oxidation. No growth occurs with sulfur alone. A. cryptum is an obligate chemoorganotroph. Thiobacillus acidophilus grows equally well with either elemental sulfur or glucose as a sole energy source; this organism is a facultative autotroph. Since the name T. acidophilus does not appear on the Approved Lists of Bacterial Names, it is revived here, and strain ATCC 27807 is designated the type strain. Thiobacillus perometabolis is considered a subspecies of Thiobacillus intermedius on the basis of close phenotypic similarity and deoxyribonucleic acid homology. Thiobacillus sp. strain A2 is a distinctive mixotroph that shows little deoxyribonucleic acid homology with other species of Thiobacillus. This organism is named Thiobacillus versutus, and strain ATCC 25364 is designated the type strain.