Cell sorting analysis of geographically separated hypersaline environments
Biogeography of microbial populations remains to be poorly understood, and a novel technique of single cell sorting promises a new level of resolution for microbial diversity studies. Using single cell sorting, we compared saturated NaCl brine environments (32–35 %) of the South Bay Salt Works in Chula Vista in California (USA) and Santa Pola saltern near Alicante (Spain). Although some overlap in community composition was detected, both samples were significantly different and included previously undiscovered 16S rRNA sequences. The community from Chula Vista saltern had a large bacterial fraction, which consisted of diverse Bacteroidetes and Proteobacteria. In contrast, Archaea dominated Santa Pola’s community and its bacterial fraction consisted of the previously known Salinibacter lineages. The recently reported group of halophilic Archaea, Nanohaloarchaea, was detected at both sites. We demonstrate that cell sorting is a useful technique for analysis of halophilic microbial communities, and is capable of identifying yet unknown or divergent lineages. Furthermore, we argue that observed differences in community composition reflect restricted dispersal between sites, a likely mechanism for diversification of halophilic microorganisms.
KeywordsHaloarchaea Cell sorting Genome amplification Biogeography Nanohaloarchaea Prokaryotic speciation
This work was supported by grants to R.T.P from the National Science Foundation (award numbers 0919290 and 080024), the U.S.–Israel Binational Science Foundation (award number 2007043), and NASA Astrobiology: Exobiology and Evolutionary Biology Program (award number NNX12AD70G). We extend special thank you to Forest Rohwer (San Diego State University, USA) and Francisco Rodríguez-Valera (University Miguel Hernández, Spain) who sampled the Chula Vista and Santa Pola salterns, respectively.
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