PHYLOGENETIC POSITION OF SULFOBACILLUS THERMOSULFIDOOXIDANS - DETERMINATION BASED ON 5S AND 16S RIBOSOMAL-RNA SEQUENCE-ANALYSIS

The nucleotide sequence of the 16S rRNA gene of the type strain Sulfob acillus thermosulfidooxidans VKM-1269 was determined. This microorgani sm belongs to the group of thermophilic acidophilic chemolithotrophic bacteria capable of utilizing elemental sulfur and iron ions as the on ly energy sources. The phylogenetic position of the bacterium studied among Gram-positive bacteria was estimated by a comparative analysis o f 16S rRNA nucleotide sequences. It was shown that Sulfobacillus forms a coherent group with species of a new genus Alicyclobacillus. The Su lfobacillus-Alicyclobacillus group is suggested to represent a separat e evolutionary branch within the clostridial subdivision of Gram-posit ive bacteria.