Salt flat microbial diversity and population structure along a salinity gradient

In this study, we examined the abundance of microbial communities in coastal sabkha and sabkha-shore regions in Abu Dhabi, UAE using 16s rDNA, and performed whole-genome metagenome analysis to elucidate the genetic heterogeneity of microbial species. Based on the 16s rDNA based prokaryotic microbial profile, we identified unusual coastal sabkha-specific microbial communities, consistent with the whole genome metagenome analysis. Out of 225 assembled microbial metagenomes, we analyzed 82 of the most abundant assembled genomes at the order and class taxonomic levels. We observed diversity was higher for some microbial populations on the inner regions of the sabkha as well as outside it, although the overall population diversity was higher within the sabkha. Our results show genetic structure over local spatial scales, different level of homologous recombination for different species as well as gene-specific selective sweeps. These results pave the way to understanding the ecological roles, salt stress tolerance mechanisms, and potential applications of sabkha microbial genes.