Cultivated bacteria from the sub-ice algae-bacterial communities of Lake Baikal

Abstract

A collection of pure cultures isolated from the sub-ice algae-bacterial communities inhabiting the lower ice surface of Lake Baikal was obtained. The differences in morphology of the cultured bacteria and their enzymatic activities were revealed by the methods of classical microbiology. The taxonomic affiliation of several cultures was determined by the 16S rRNA gene sequencing. They belong to the genera Pseudomonas putida, P. psychrophila, Methylobacterium extorquens, Rhodococcus aerolatus, Brevundimonas aurantiaca, B. vesicularis, Sphingomonas subarctica, Roseomonas frigidaqua, and Janthinobacterium lividum. These taxa are adapted to low-temperature environments. Key words: Lake Baikal; sub-ice communities; microalgae; bacteria; enzymatic activity; 16S rRNA sequencing

Variability of Microbial Communities in Two Long-Term Ice-Covered Freshwater Lakes in the Subarctic Region of Yakutia, Russia

“…All the bacterial strains were subcultured every 3 month and kept at 4 °С, 10 °С and 25 °С. The procedure described in Bashenkhaeva and Zakharova [24] was used for counting the abundance, isolating bacterial strains, extracting DNA, and deriving amplicons of 16S rRNA gene fragments. PCR ampli cation of the obtained DNA was performed using universal primers for the 16S rRNA gene of eubacteria 27F (AGA GTT TGA TCM TGG CTC AG), 500L (CGT GCC AGC AGC CGC GGT AA) and 1350R (GAC GGG CGG TGT GTA CAA G) [39,40].…”

“…It was not surprising, as Pseudomonas grew well on depleted media and successfully competes in heterotrophic conditions. Pseudomonas is a cosmopolitan genus found in different habitats of cold ecosystems [24,56,[64][65][66]. Some Pseudomonas developed different strategies of survival and colonization of extremely cold habitats, including polyunsaturated fatty acid biosynthesis, mRNA chaperones, and other cold-inducible proteins [67,68].…”

“…The temperate oligotrophic Lake Stechlin (Germany) was investigated for the composition and activity of under-ice heterotrophic bacteria during the decay of blooming cyanobacteria Aphanizomenon osaquae [22]. The taxonomic composition, richness, and dynamics of bacterial communities on the bottom ice surface and in the water column under the ice were studied during the peak of bloom of dominating complex of plankton in the oligotrophic Lake Baikal [23][24][25][26], and the genomes of Baikal subglacial bacteria were assembled [27]. Seasonal dynamics of the microbial community structure during ice formation and after as well as the bacterial carbon cycle were demonstrated for the Great Lakes [13,28].…”