Sulfobacillus thermosulfidooxidans | |
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Image of Sulfobacillus thermosulfidooxidans | |
Scientific classification | |
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Species: | S. thermosulfidooxidans |
Binomial name | |
Sulfobacillus thermosulfidooxidans Golovacheva and Karavaiko 1991 [1] | |
Sulfobacillus thermosulfidooxidans is a species of bacteria of the genus Sulfobacillus . It is an acidophilic, mixotrophic, moderately thermophilic, Gram-positive, sporulating facultative anaerobe. As its name suggests, it is capable of oxidizing sulfur. [2] [3] [4]
S. thermosulfidooxidans, as well as the genus Sulfobacillus , were first described in 1978 based on isolates from Kazakhstan. [5] [1] S. thermosulfidooxidans is the type species of the genus. [1] The genus is of uncertain taxonomic position, [3] [1] likely related to the genus Thermaerobacter and possibly representing either a deep branch of the Bacillota or a separate phylum. [3] [6]
S. thermosulfidooxidans is widely distributed in both natural and artificial acidic environments, including hot springs and acid mine drainage. Strains have been isolated from a variety of locations including China, [7] Chile, [4] Kazakhstan, [5] California, [2] and Zambia. [7] Compared to other bacteria often found in similar environments, Sulfobacillus species are typically present at relatively low abundance. [2] [7]
S. thermosulfidooxidans is acidophilic and moderately thermophilic; while different strains have slightly different pH and temperature growth optima, all prefer environments around pH 2.0 with optimal growth temperatures ranging from 45C to 55C. [5] [8] [3] [4] S. thermosulfidooxidans is iron- and sulfur-oxidizing, capable of oxidation of elemental sulfur, tetrathionate, and sulfides. [2]
The genomes of several S. thermosulfidooxidans strains have been sequenced, demonstrating a genome size of 3.2-3.9 megabases, with a GC content of 48-49% [4] [2] [3] [7] and a number of bioinformatically defined protein-coding genes ranging from a low of about 3200 [3] to a high of about 3900. [2] All of the sequenced genomes contain large numbers of genes associated with sulfur oxidation; for example, genes encoding sulfur oxygenase reductase (SOR) and heterodisulfide reductase-like enzymes. [2] [3] [7] The genetic basis of the species' iron oxidation capacity is less clear but likely involves a sulfocyanin protein. [2] [3] [7] The genome also contains large numbers of transport proteins, including those specialized for metal ion efflux, and several CRISPR/Cas systems. [3] There is evidence of horizontal gene transfer as a significant contributor to S. thermosulfidooxidans evolution, including an unexpected relationship between a SOR gene and similar genes found only in archaea. [2] [3] [7]