GENOMIC VARIABILITY IN THIOBACILLUS-FERROOXIDANS AND ITS ROLE IN BIOHYDROMETALLURGICAL PROCESSES

This review considers certain aspects of the natural and experimental variability of Thiobacillus ferrooxidans revealed at the genome level: variations in the DNA nucleotide composition; the role of plasmids in cell metabolism and their use for obtaining strains with enhanced res istance to metals; mobile repeated DNA sequences and their role in the adaptation of T. ferrooxidans to variable environmental conditions; p eculiarities in the structure of chromosomal DNAs in strains of differ ent origin and in strains adapted to growth on media with a high metal content or with new substrates. The high variability of T. ferrooxida ns enables it to develop under extreme natural conditions and determin es the leading role of this bacterium in biohydrometallurgical process es under mesophilic conditions. The authors assume that, in the proces s of evolution under extreme conditions, T. ferrooxidans has acquired mechanisms for phenotype variation that are based on changes in the ge nome structure.