Analysis of microbial communities of thermal springs of lake fumarolnoe area, Uzon volcano Caldera, Kamchatka

For the first time complex molecular-biological studies of microbial communities of 5 thermal springs, located around Lake Fumarolnoe, Uzon volcano caldera, Kamchatka, is conducted. The methods based on PCR technologies (PCR-detection, PCR-DGGE, cloning) and fluorescence in situ hybridizations (FISH) for analysis of ribosomal and functional genes, which are responsible for synthesis of key enzymes of methanotrophy, methanogenesis, autotrophic СО2 fixation, nitrification have been used. We found that aggregate number of microorganisms in sludge samples varied from 0.5 to 36.8×106 cells/ml, and metabolically active eubacteria shared 22-35 %. Representatives of Bacteria and phototrophic prokaryotes have been found out by PCR in all thermal springs, Archаea - in four, and methanotrophs - in three. No methanogens and nitrifying archaea were detected in any of the springs. For the first time in hydrotherms methanotrophic communities are studied, and the low diversity presented only methanotrophs of I type, most closely related to Methylothermus and Methylobacter, is revealed. We isolated 5 enrichment monocultures of extremely thermophilic methanotrophs, which structure includes organisms, considerably different from two known species of genera Methylothermus.