PECULIARITIES IN THE CHROMOSOMAL DNA-STRUCTURE IN SULFOBACILLUS THERMOSULFIDOOXIDANS ANALYZED BY PULSED-FIELD GEL-ELECTROPHORESIS

A polymorphism of the chromosomal DNA structure in Sulfobacillus therm osulfidooxidans cultures was studied by pulsed-field gel electrophores is. The structure of DNA from the type strain VKM B-1269 remained stab le regardless of the energy source (yeast extract, Fe2+, S-0, sulfide minerals, ore concentrate) used by the culture, whereas changes in the genome of the non-spore-forming strain S. thermosulfidooxidans subsp. asporogenes 41 were revealed upon switching the culture from the oxid ation of yeast extract to the oxidation of elemental sulfur. A microbi al culture, outgrowing strain VKM B-1269 under certain conditions, cap able of oxidizing Fe2+, and possessing a NotI-restriction pattern of c hromosomal DNA distinct from those of the known S. thermosulfidooxidan s cultures, was isolated during continuous cultivation under non-steri le conditions in laboratory apparatus and during semi-industrial leach ing of gold from an ore concentrate obtained from the Nezhdaninskoe de posit.