Culturable Bacterial Communities Isolated from Cryo-Arid Soils: Phylogenetic and Physiological Characteristics

The results of the phylogenetic analysis and analysis of the physiological characteristics of metabolic activity of strains isolated from frozen sedimentary rocks collected in the Antarctic and the Severnaya Zemlya archipelago are reported in this article. A comparable abundance of cultured cells and close morphological diversity of colony morphotypes were revealed in all samples. Representatives of the Actinobacteria and Firmicutes phyla were predominant in the cultured bacterial communities. These communities were characterized by mesophilic and neutrophilic optima, as well as by the wide ranges of temperatures and pH suitable for metabolic activity. Moderate halotolerance in the presence of sodium or potassium chloride, as well as the high inhibitory effect of sodium hydrocarbonate and low inhibitory effect of magnesium sulfate, were revealed. The communities were highly resistant to the presence of 5% magnesium perchlorate in the culture medium. Strains resistant to antibiotics in the composition of the medium were revealed: The isolated strains were the most resistant to ampicillin, chloramphenicol, and cephalexin.