Molecular diversity of heterotrophic bacteria and archaea of Namakdan Cave in Qeshm

Given the high diversity, biotechnological applications and the effective role of bacteria in making and maintaining the ecosystem balance; biodiversity research are very important. Meanwhile, the halophilic bacteria and archaea have been considered because of their biotechnological importance and specific ecological condition. In this study, we investigated the diversity of heterotrophic bacteria and archaea of Namakdan cave in Qeshm Island.
This cross-sectional study was carried out by sampling from Qeshm Namakdan cave in November 2013. The diversity of the cave heterotrophic aerobic bacteria was analyzed using the culture method. Halophilic and halotolerant bacteria and Archaea under aerobic conditions were isolated by MGM and Marine agar media, respectively. Isolates were separated according to morphological differences, and primary biochemical features. Finally, 16s rRNA sequencing was performed for 32 isolates.
Among 172 isolates 16S rRNA sequencing was carried out for 27 strains. Phylogenetic analysis placed archaea in the euryarchaeota division and Halococcus, Haloferax, Haloarcula, Halogeometricum genus branches and bacteria in Firmicutes and Bacteroides divisions and in Aliifodinibius, Paenibacillus, Aquibacillus, Paraliobacillus, and Bacillus genus branches. Among the sequenced isolates, 11 isolates showed less than 89.7% similarity to the standard species, which is considered as a borderline point to present new microbial species.
Placing the identified isolates in different phylogenetic divisions and genus branches demonstrates the wide microbial diversity of Qeshm Namakdan cave ecosystem. Presenting native microorganisms in new species and genera from unique ecosystems by introducing new genetic content provides access to new native genes and pathways.