Diversity of halophilic and halotolerant bacteria in the largest seasonal hypersaline lake (Aran-Bidgol-Iran).

Abstract

In this study, the culturable halophilic and halotolerant bacterial diversity was determined in Aran-Bidgol as a thalassohaline seasonal hypersaline lake in Iran. Thirty water, soil, sediments, coastal mud, multi-color brines and salt crystals samples were extracted and cultured using different media and incubation conditions. Totally 958 isolates were obtained and 87 isolates were selected for further studies, based on morphological, physiological and biochemical tests, representing different morphotypes. Based on 16S rRNA gene sequence analyses, the isolates exhibited 94.6-100% sequence similarity to the closest known species of the genera Bacillus, Halomonas, Oceanobacillus, Salinicoccus, Thalassobacillus, Ornithinibacillus, Halobacillus, Salicola, Virgibacillus, Aerococcus, Arthrobacter, Idiomarina, Paraliobacillus, Staphylococcus, Acinetobacter, Aneurinibacillus, Brevibacillus, Brevundimonas, Chromohalobacter, Gracilibacillus, Jeotgalicoccus, Kocuria, Marinilactibacillus, Marinobacter, Microbacterium, Paenibacillus, Paracoccus, Piscibacillus, Pseudomonas and Sediminibacillus and also, comparison of ARDRA patterns among the sequenced strains, using AluI, Bst UI and Hpa II enzymes showed that these patterns are in accordance with the phylogenetic position of these strains. The PCR-RFLP analyses suggested that ARDRA possess a functional potential for distinguishing halophilic bacteria to be used for further studies in elementary steps of isolation to reduce the tedious duplication of isolates.