METHANOTROPHIC BACTERIA IN SALINE RESERVOIRS OF UKRAINE AND TUVA

The consumption of methane by sludge samples from reservoirs of Ukrain e and Tuva with salinities from 1 to 20% was shown by the radioisotope method. Enrichment cultures of microbial associations dominated by mo rphotype I methanotrophic bacteria were obtained. A NaCl-dependent bac terium with an optimum pH of 9.0 was isolated in pure culture and prel iminarily identified as Methylobacter sp. 20z. The optimum NaCl concen tration for its growth was 4%, and the upper limit of halotolerance wa s 9%, which is significantly higher as compared to pure cultures of Na Cl-requiring methanotrophs described earlier. The results indicated th e presence of methanotrophic bacteria in saline reservoirs with a wide range of NaCl concentrations.