Isolation of some bacteria for halophilic microbiome of Urmia Lake

Urmia Lake is the largest lake in the Iranian plateau and the second largest Salt Lake in the world. This study was conducted to identify hypersaline bacteria in the lake through the screening with molecular markers. For the molecular study of the bacterial microbiome of the lake, samples were collected from water, sludge and soil of the different parts of the lake during different seasons of 2018 and 2019, and then transferred to the laboratory under standard conditions. Bacterial isolates were purified from the samples using universal culture media. ERIC molecular marker was used to study the species diversity. After clustering analysis of the species on the basis of their genetic markers, one bacterium from each cluster was selected as the representative of each cluster and then identified by DNA barcoding method using the 16srDNA. Biochemical tests were performed to confirm the molecular results. In total, 102 bacterial isolates were isolated and purified from the samples, of which only 29 isolates were extremely-halophilic. The molecular diversity of isolates, based on ERIC molecular marker, showed that isolates can be assigned to five different clusters. Five isolates selected from each cluster were selected and their 16SrDNA region were amplified and sequenced with 16SrDNA-specific primers. The results showed that the five selected isolates with 99% similarity belonged to the species Microbulbifer halophilus, Halomonas salina, Bacillus sonorensis, Salinivibrio costicola and Bacillus aquimaris. The results of molecular identification were consistent with the results of biochemical tests.