Characterization of microbial communities from the water and endemic sponges Lubomirskia Baikalensis of Lake Baikal during environmental changes

The ecological crisis in the coastal zone of Lake Baikal, which began in 2010-2011, caused changes in the taxonomic composition of microbial communities in the water and sponges. To identify these changes and their possible cause, we analyzed and compared the composition and diversity of microbial communities in the Baikal bacterioplankton and endemic sponges, Lubomirskia baikalensis, using high−throughput 16S rRNA sequencing. The microbial diversity in the Baikal bacterioplankton was higher than in the microbiome of the sponge body L. baikalensis. By 2015, the microbial community in sponges consisted of abundant Cyanobacteria, Bacteroidetes, Proteobacteria, and Actinobacteria and became more similar to the biofouling community. Bacteria associated with human activity were often found in the water and sponge communities. During this period, the amplicon sequences of some opportunistic human pathogens were detected in the coastal water and sponges. The obtained results dramatically demonstrate the anthropogenic impact on the ecosystem of the coastal zone of Lake Baikal.