Screening and identification of microorganisms isolated from bottom sediments of lake Baikal

Lake Baikal is located in the inland rift zone in the south of central Siberia. It is the deepest lake in the world, containing the largest volume of fresh water in a single body of water. Microbial communities of Lake Baikal can have significant biomass and form the so-called microbial mats. This work aims to screen and identify microorganisms isolated from the bottom sediments of Lake Baikal. Screening of microorganisms was carried out. Isolates of microorganisms were obtained as follows: extraction with phenol/chloroform and purification with a cetyl-trimethyl ammonium bromide solution was used to isolate DNA from the analyzed samples. Bacteria were differentiated according to the biochemical properties of their cell walls by Gram staining. The genetic diversity of the isolated microorganisms was investigated by Random Amplified Polymorphic DNA analysis using the Lmbd - GGGCGCTG primer. The research resulted in isolation of 7 isolates with different morphological characteristics from the microbial communities of Lake Baikal bottom sediments. It was found that among rod-shaped bacteria there are both gram-positive (isolate 1) and gram-negative (isolates 2, 3, 4, 6, 7) forms. The species of microorganisms were determined isolate 1 - Bacillus megaterium, isolate 2 - Pseudomonas fluorescens, isolate 3 - Pseudomonas putida, isolate 4 - Pseudomonas aeruginosa, isolate 5 - Micrococcus luteus, isolate 6 - Pseudomonas oleovorans, isolate 7 - Acinetobacter calcoaceticus. The study of microorganisms in the Lake Baikal sediments will lead to a better understanding of basic biological processes such as the structure and function of membranes or the structure of proteins under low ionic strength conditions.