Isolation and Characterization of Halophilic and Halotolerant Bacteria from Urmia Lake after the Recent Drought Disaster in 2015

Background: Due to the last two decades of drought disaster, which resulted in the loss of the main part of Urmia Lake water and changed the natural conditions of an environment, especially ionic strength. Objective: We aimed to isolate and characterize halophilic and halotolerant bacteria in Urmia Lake, Iran, 2015. Urmia Lake is a permanent and salty inland lake located in the Azerbaijan region in northwestern Iran. Methods: Sampling was carried out in multiple water-filled locations of the lake. Liquid basal media for the enrichment of bacteria was successively applied and colonies were isolated by the plating method. Isolates were then distinguished based on differences in colony, Gram staining, microscopic shape, and biochemical properties. Results: One chemolithotrophic isolate belonging to Thiobacillus thioparus and 41 heterotrophic isolates were obtained. The 16S rRNA gene sequences showed that all 42 isolates belong to the genera Kocuria (21.42%), Marinobacter (11.90%), Micrococcus (11.90%), Thalassobacillus (11.90%), Bacillus (11.90%), Halomonas (7.14%) and Thiobacillus (2.38%). Conclusion: Based on 16S rRNA similarity, 5 of 41 isolates showed the potential to be introduced as new species. The dominant genera with abounded frequency were found to be Kocuria, Bacillus and Thalassobacillus genera.