Halophilic Prokaryotes in Urmia Salt Lake, a Hypersaline Environment in Iran

In this study, fluorescence in situ hybridization (FISH) and PCR-amplified fragments of the 16SrDNA gene were used to determine prokaryotes diversity in Urmia Salt Lake. Prokaryote cell population in Urmia lake range from 3.1 ± 0.3 × 10⁶, 2 ± 0.2 × 10⁸, 4 ± 0.3 × 10⁸, and 1.8 ± 0.2 × 10⁸ cells ml^-1 for water, soil, sediment, and salt samples by DAPI (4́, 6-diamidino-2-phenylindole) direct count, respectively. The proportion of bacteria and archaea in the samples determinable by FISH ranged between 36.1 and 55% and 48.5 and 55.5%, respectively. According to the DGGE method, some bands were selected and separated from the gel, then amplified and sequenced. The results of sequences were related to two phyla Proteobacteria (16.6%) and Bacteroidetes (83.3%), which belonged to four genera Salinibacter, Mangroviflexus, Pseudomonas, and Cesiribacter, and the archaeal sequences were related to Euryarchaeota phyla and three genera Halonotius, Haloquadratum, and Halorubrum. According to our results, it seems that prokaryotic populations in this hypersaline environment are more diverse than expected, and bacteria are so abundant and diverse and form the metabolically active part of the microbial population inhabiting this extreme environment. Molecular dependent and independent approaches revealed a different aspect of this environment microbiota.