ULTRAMICROBACTERIA AND FILTERABLE BACTERIA IN THE PLANKTON OF LAKE BAIKAL

In Lake Baikal, the number, diversity and structure of femtoplankton – bacteria passing through filters with a pore size of 0.2 μm were studied for the first time using a complex of methods. The bacterial abundance in the femtoplankton fraction was 7×104 cells/ml in the 0-50 m water layer as measured by epifluorescence microscopy, and their contribution to the total bacterial number reached an average of 4.4%. High throughput sequencing of 16S rRNA gene fragments revealed a significant genetic and taxonomic diversity of femtobacterioplankton in the pelagic and littoral zones of the lake. Dominant and minor phyla, orders, families, genera, and phylotypes of bacteria were identified in two fractions of the Lake Baikal bacterioplankton larger and smaller than 0.2 µm; the contribution of ultrasmall bacteria to the taxonomic composition of microbial communities in different parts of the lake was determined. Significant differences in the microbiomes of bacterioplankton and femtobacterioplankton fractions were revealed, and the peculiarities of ultramicrobacteria composition were described. The results showed an important role of ultrasmall bacteria in the Lake Baikal ecosystem. 

This repository contains raw sequencing data from DNA metabarcoding and metadata with samples description for the current study.