Adaptation of natural yeast strains to heavy metal and radionuclides salts
Ability of natural yeast strains to grow in conditions of high concentrations of heavy metal and radionuclides salts was studied. More than 500 strains were tested for resistance to salts of heavy metals (U, Cs, Sr, Ni, Ar, Cu, Cd, and Co) and to elevated temperature (t) (+37...452 °C). Most of the strains tested were resistant to one or more selective factors. Combinations of (t, Cd, Cu, Co) and (Cd, Cu, Co) occurred with the highest frequencies: 36 and 26 %, respectively. Ability of isolated strains to grow in the presence of high concentrations of radioactive isotopes Cs and Ni and to bind them with high efficiency was established. The results showed the possibility of potential using of libraries of natural microorganisms for disposal of both radionuclides and heavy metals, which are the main pollutants of natural and anthropogenic objects, as well as the possibility of using of isolated and tested strains of microorganisms for concentrating metals from low-grade ores or mining industry waste. Phenotypes diversity revealed indicates probable existence of several mechanisms of resistance to high heavy metals concentrations.