ISOLATION OF THE LYSOGENIC ACTINOBACTERIUM FROM THE RESERVOIR OF MELTWATER OF ANCIENT ICE WEDGE FROM THE PLEISTOCENE GLACIAL COMPLEX OF MAMONTOVA GORA (YAKUTIA, RUSSIA)тезисы доклада
Дата последнего поиска статьи во внешних источниках: 1 февраля 2021 г.
Аннотация:The most expressed exposures of permafrost ice wedges are in the region of Mamontova Gora on the left bank of the Aldan River (CentralYakutia). Seasonal thawing of relic ice wedge layers is followed by the formation of a reservoir where the meltwater stagnates and then ends up in the Aldan River in the form of water flows. A novel actinobacterium, designated K3–2, was isolated from samples of the reservoir of meltwater. Strain K3–2 formed orange–yellow, circular and smooth colonies that were approximately 1.0–2,0 mm in diameter after 2–3 days cultivation at 28°C on an ISP1or ISP3 agar plate. Cells of the strain were irregular, short rod-shaped (0.3–0.6 × 1.0–3.0 μm), gramstain-positive, non-motile and non-endospore-forming. Cells in older cultures tended to be shorter and rounder. The strain was also catalase- and oxidase-positive. Growth occurred at 20° – 30°C. The pH range for growth was 5.0–7.0. Optimal growth was noted at 28°C and pH 7.0. The strain exhibited good growth with NaCl concentrations of 0–7 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain K3–2 was related to members of the family Beutenbergiaceae. The highest 16S rRNA gene sequence similarity value was observed with Serinibacter salmoneusKis4–28T (97.2 %) and Serinibacter tropicus PS-14–7T (97.2 %). Subsequent analysis of 16S rRNA gene sequences confirmed belonging of the strain K3–2 to the genus Serinibacter and detachment from two of its known species Serinibacter salmoneus Kis4–28T and Serinibacter tropicus PS-14–7T. The strain Serinibacter sp. K3–2 is deposited in three international collections (VKM Ас-2719, VKPM Ас-2020, DSM 103859).In the analysis population of the strain Serinibacter sp. K3–2 phage plaques were detected in the zone of active growth of some bacterial colonies. Small negative colonies (0.15–0.2 mm) were detected after 3–5 day incubation. The formation of phage plaques was observed visually or under a phase contrast microscope. To elucidate where these negative zones come from, samples taken from the plaques and the filtrate obtained by filtering the culture liquid of the lysogenic isolate Serinibacter sp. K3–2. To detect intracellular phage particles ultra-thin sections of Serinibacter sp. K3–2 were observed through transmission electron microscope. As a result, phage particles of morphologically spherical type were detected in all variants.