Bacterial Communities of Frozen Quaternary Sediments of Marine Origin on the Coast of Western Spitsbergen

The bacterial composition of permafrost samples taken during drilling of frozen marine sediments in the area of Barentsburg coal mine on the east coast of Grønfjord Bay of Western Spitsbergen has been studied. The study was based on the analysis of the V4 region of the 16S rRNA gene, carried out using next generation sequencing, as well as using classical microbiological methods (direct luminescence microscopy and aerobic cultivation).The total cell number in permafrost samples ranges from 6.73 ± 0.73 × 106 to 3.37 ± 0.19 107 cells per g. The number of cultivable aerobic bacteria in frozen samples on 1/5 TSA and R2A media ranges from 0 to 6.20 ± 0.45 × 104 CFU/g. Isolates of aerobic bacteria were identified by 16S rRNA gene analysis as representatives of the genera Arthrobacter, Pseudarthrobacter, Psychrobacter, and Rhodoferax. The dominant phyla of the domain Bacteria were Actinobacteria, Proteobacteria, Chloroflexi, Nitrospirae and Firmicutes. As a result of phylogenetic analysis of the dominant operational taxonomic units, representatives of methane oxidizing, sulfate reducing bacteria, as well as heterotrophic bacteria involved in the transformation of organic matter were found.