Archaeal communities of frozen Quaternary sediments of marine origin on the coast of Western Spitsbergen,

The archaeal composition of permafrost samples taken during drilling of frozen marine sediments in the area of the 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. This is the second part of the work dedicated to the prokaryotic composition of the Western Spitsbergen, the fi rst part was devoted to the domain of Bacteria. The general phyla of the the Archaea domain were Euryarchaeota, Bathyarchaeota, Thaumarchaeota and Asgardarchaeota. As a result of phylogenetic analysis of the dominant operational taxonomic units, representatives of methanogenic methane- and ammonium-oxidizing archaea, as well as heterotrophic archaea were found. Methanobacteria class of methanogenic archaea was found in the controversial genesis, while methane-oxidizing archaea of the Methanomicrobia class of Methanosarcinales order were found in the marine permafrost of Cape Finneset: ANME-2a, -2b group was found in layers 8.6 and 11.7 m, and a group ANME-2d (Candidatus Methanoperedens) – in a layer of 6.5 m. Ammonium-oxidizing archaea of the phylum Thaumarchaeota was present in all types of permafrost, while Nitrososphaerales was detected in controversial genesis permafrost, and the order-Nitrosopumilales in the marine permafrost or controversial genesis ones. Representatives of phylum Bathyarchaeota were found in the stratigraphicly most ancient samples under this study. Superphylum Asgardarchaeota was met exclusively in the layers of permafrost with marine genesis and was represented by phyla Lokiarchaeota, Thorarchaeota and another group belonging to this superphylum that was not identified by us. The presence in the marine permafrost terrace of Cape Finneset at 11.7 m depth of methane, ethylene and ethane, as well as the composition of the archaeal community gives this layer to assume in it the presence of microbiological processes of the anaerobic oxidation of methane, probably received from Tertiary deposits before freezing. The results obtained are represented the permafrost of Spitsbergen as a rich archive of genetic information of little studied prokaryotic groups

Microbial communities within the water column of freshwater Lake Radok, East Antarctica: predominant 16S rDNA phylotypes and bacterial cultures

Antarctic lake ecosystems provide a rare opportunity to study the evolution and adaptation of microorganisms to extreme conditions, as well as to discover new species useful for biotechnological applications. Four water samples were collected from various layers of the water column of freshwater Lake Radok in East Antarctica. Two regions (v3-v5 and v4-v8) of the 16S rRNA gene were amplified by PCR and sequenced. Twenty dominant phylotypes were detected representing five bacterial phyla (Actinobacteria, α, β and δ Proteobacteria, Bacteroidetes, Planctomycetes, OD1) and two eukaryotic divisions (stramenopiles and green algae). Of these, 16 phylotypes demonstrated ≤98\ua0% identity to the nearest taxa in GenBank and were therefore classified as new unknown species. Seven phylotypes demonstrated ≤90\ua0% identity and thus remained unidentified. Actinobacteria was the most abundant phylum with 157 clones (41\ua0% of the total number) representing 5 phylotypes. A species complex (3 clades from acI-A subgroup) of Candidatus Planktophila limnetica was prevalent in all layers. Representatives of the OD1 phylum and δ-proteobacteria were discovered by sequencing of the v3-v5 region of 16S rRNA, while Planctomycetes, β-proteobacteria and mtDNA of stramenopiles were discovered by sequencing of the v4-v8 region. This highlights the necessity of sequencing at least two 16S rRNA gene regions to gain more data on microbial community characterization. In general, despite the uniformity in the physical and chemical properties in the water column, a prominent stratification of microbial groups was observed, at the levels of both divisions and phylotypes

Bosea caraganae sp. nov. a new species of slow-growing bacteria isolated from root nodules of the relict species Caragana jubata (Pall.) Poir. originating from Mongolia

Two Gram-stain-negative strains, RCAM04680(T) and RCAM04685, were isolated from root nodules of the relict legume Caragana jubata (Pall.) Poir. originating from the south-western shore of Lake Khuvsgul (Mongolia). The 16S rRNA gene (rrs) sequencing data showed that these novel isolates belong to the genus Bosea and are phylogenetically closest to the type strains Bosea lathyri LMG 26379(T), Bosea vaviloviae LMG 28367(T), Bosea massiliensis LMG 26221(T) and Bosea lupini LMG 26383(T) (the rrs-similarity levels were 98.7-98.8 %). The recA gene of strain RCAM04680(T) showed the highest sequence similarity to the type strain B. lupini LMG 26383(T) (95.4 %), while its atpD gene was closest to that of B. lathyri LMG 26379(T) (94.4 %). The ITS, dnaK and gyrB sequences of this isolate were most similar to the B. vaviloviae LMG 28367(T) (86.8% for ITS, 90.4% for the other genes). The most abundant fatty acid was C-18:1 omega 7c (40.8 %). The whole genomes of strains RCAM04680(T) and RCAM04685 were identical (100% average nucleotide identity). The highest average nucleotide identity value (82.8 %) was found between the genome of strain RCAM04680(T) and B. vaviloviae LMG 28367(T). The common nodABC genes required for legume nodulation were absent in both strains; however, some other symbiotic nol, nod, nif and fix genes were detected. Based on the genetic study, as well as analyses of the whole-cell fatty acid compositions and phenotypic properties, a new species, Bosea caraganae sp. nov. (type strain RCAM04680(T) (=LMG 31125(T)), is proposed