부산대학교 도서관

The rates of microbial processes and phylogenetic diversity of the microorganisms responsible for organic matter production and decomposition in the benthic communities and bottom sediments of the rivers Solyanka, Lantsug, Khara, Chernavka, and Bol'shaya Smorogda (Lake Elton area, Volgograd oblast, Russia) were studied. The biomass and primary production of cyano-bacterial communities varied significantly within the ranges of 20-903 mg Chl a/m and 0.2-21 mg C/(m h), respectively. Depending on the season, the share of anoxygenic CO fixation varied from 20% to the values comparable to the rate of oxygenic photosynthesis. The total heterotrophic activity of microbial communities determined as the rate of dark CO assimilation varied from 31 to 750 μmol/(dm day) in the mats and from 3 to 137 μmol/(dm day) in the sediments. The rates of sulfate reduction and hydrogenotrophic methanogenesis varied from 10 to 2621 μmol S/dm day) and from 1.5 to 323 nmol CH/(dm day), respectively. High-throughput sequencing of the 16S rRNA genes in cyano-bacterial mats revealed microorganisms belonging to 20 phyla, with the sequences of Cyanobacteria, Proteobacteria, and Bacteroidetes being the most numerous. [ABSTRACT FROM AUTHOR]