Abundant and Rare Microbial Subcommunities in Soda Lake Nukhe-Nur (Barguzin Depression, Russia)

In this study, we first investigated the composition of microbial communities of abundant, intermediate and rare subcommunities in soda Lake Nukhe-Nur (the Barguzin Basin) using Illumina MiSeq high-throughput sequencing. The results showed that abundant subcommunities mainly consisted of Pseudomonadota, Cyanobacteriota, Bacteroidota и Bacillota. In contrast, the rare subcommunities in the microbial mats were mainly composed of Pseudomonadota, Cyanobacteriota, Bacillota, Deinococcota, Gemmatimonadota, Bacteroidota, Actinobacteriota, Kiritimatiellaeota. In the rare subcommunity of the bottom sediments, Euryarchaeota, Actinobacteriota, Pseudomonadota, Bacillota, Bacteroidota, Chloroflexota, Gemmatimonadota, Verrucomicrobiota, Epsilonbacteraeota, and Deinococcota were found. However, the dominant phyla of the abundant subcommunity were also found in the intermediate and rare subcommunities. The predictive analysis of the microbial ecological function has revealed a broad potential diversity of metabolic pathways in the abundant, intermediate, and rare subcommunities of microbial mats and bottom sediments in Lake Nukhe-Nur. In soda lakes, rare subcommunities may play a greater role in the decomposition of organic matter than do abundant subcommunities. Overall, this study provides a better understanding of the microbial community structure and potential ecological functions of abundant and rare subcommunities in soda lakes ecosystems. The identified rare taxa open new opportunities for ecological, taxonomic, and genomic discoveries in Barguzin soda lakes.