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Aim. The research was focused on the assessment of the possible resistance of Antarctic microorganisms to mercury ions. Methods. Conventional microbiological methods of introducing of decimal dilutions to agar medium. Results. Microorganisms resistant to Hg2+ in high concentrations (up to 500 mg/l) were discovered among samples from Antarctica. The majority of Hg2+-resistant microorganisms was found in moss-lichen and soil ecosystems. The least of Hg2+-resistant microorganisms was found in organics-rich humus ecosystems. Conclusions. In Antarctic microbiocenoses were discovered for the first time microorganisms resistant to mercury in “bactericidal” concentrations in spite of absence of this element in the natural ecosystems. Apparently, the genome of these microorganisms contains genes that provide the mechanisms of microbial resistance to toxic mercury. Keywords: mercury, metal resistance, Antarctic microorganisms.

Aim. Determination of taxonomic position and resistance to Cd2+, Cu2+, Ni2+, Co2+, CrO42- of isolated bacteria from cadmium-contaminated soils. Methods. Bacterial cultures were isolated by ten-fold dilutions and further cultivation on agarized nutrient medium. Taxonomic position of isolated cultures was determined by molecular-genetic methods using GenBank and BLAST. Bacterial resistance to toxic metals was determined by strains cultivation in liquid medium in the presence of concentration gradient of Cd2+, Cu2+, Ni2+, Co2+, CrO42-. Results. Isolated cultures were highly resistance to cadmium. These bacterial cultures were identified as Brevundimonas vesicularis and Cupriavidus gilardii by phenotypic and molecular-genetic characteristics. Their resistance was in one order higher comparing to generally accepted. Conclusions. Isolated strains are promising for using in novel industrial biotechnologies for metal containing wastewater treatment. Keywords: metalresistance, toxic metals, taxonomic position, Cupriavidus gilardii, Brevundimonas vesicularis.