An aerobic facultative thermophilic bacterium was isolated from the ore of the Nikolaev copper-zinc-pyrite deposit in the Eastern Kazakhstan. The bacterium is similar to Thiobacillus ferooxidans in the ability to use various energy subsrates (Fe2+, sulphide minerals and So) and in the acidophilic properties, but differs from it in the thermophilic nature, the structure of a cell wall, the ability to produce spores, and a lower GC content in DNA. Consequently, the organism has been identified as a new species of a new genus, Sulfobacillus thermosulfidooxidans gen. nov., sp. nov. The organism is presumed to play an active role in oxidation of sulphide ores and their warming in deposits.