Isolation and Diversity of Sediment Bacteria in the Hypersaline Aiding Lake, China

Abstract

A total of 343 bacteria from sediment samples of Aiding Lake, China, were isolated using nine different media with 5% or 15% (w/v) NaCl. The number of species and genera of bacteria recovered from the different media significantly varied, indicating the need to optimize the isolation conditions. The results showed an unexpected level of bacterial diversity, with four phyla (Firmicutes, Actinobacteria, Proteobacteria, and Rhodothermaeota), fourteen orders (Actinopolysporales, Alteromonadales, Bacillales, Balneolales, Chromatiales, Glycomycetales, Jiangellales, Micrococcales, Micromonosporales, Oceanospirillales, Pseudonocardiales, Rhizobiales, Streptomycetales, and Streptosporangiales), including 17 families, 41 genera, and 71 species. In this study, the predominant phyla included Firmicutes and Actinobacteria and the predominant genus included Halomonas, Gracilibacillus, Streptomyces, and Actinopolyspora. To our knowledge, this is the first time that members of phylum Rhodothermaeota were identified in sediment samples from a salt lake. This study has identified at least four novel isolates.