Halomonas qiaohouensis sp. nov., isolated from salt mine soil in southwest China.

Two Gram-stain negative, moderately halophilic, aerobic, motile bacteria, designated strains YIM QH88(T) and YIM QH103, were isolated from the Qiaohou salt mine in Yunnan, southwest China. Cells of the strains were observed to be rod-shaped and produce creamy-coloured colonies. Growth of the two strains was observed at 10-45 °C (optimum 25-37 °C), at pH 6.0-10.0 (optimum 7.0-8.0), and in the presence of 0.5-20 % (w/v) NaCl (optimum 2-6 %). The two strains were found to contain summed feature 8 (C18:1 ω7c/ω6c), C19:0 cyclo ω8c and C16:0 as the major cellular fatty acids. The polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unknown phospholipid. The G+C content of the genomic DNA of strains YIM QH88(T) and YIM QH103 were determined to be 64.6 and 64.2 mol%, respectively, and the predominant respiratory quinone detected was ubiquinone 9. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strains YIM QH88(T) and YIM QH103 formed a distinct lineage within the genus Halomonas and were most closely related to Halomonas pantelleriensis DSM 9661(T) with 97.3 and 97.5 % of 16S rRNA sequence similarity respectively. The DNA-DNA hybridization relatedness value for strains YIM QH88(T) and YIM QH103 was 95.2 ± 0.8 %. The levels of DNA-DNA relatedness between each of these two strains and the type strains of phylogenetically closely related Halomonas species were clearly below 70 %. On the basis of their phylogenetic analysis, DNA-DNA hybridization relatedness, phenotypic and chemotaxonomic characteristics, strains YIM QH88(T) and YIM QH103 should be classified as a novel species of the genus Halomonas, for which the name Halomonas qiaohouensis sp. nov. is proposed. The type strain is YIM QH88(T) (=DSM 26770(T) =CCTCC AB 2012965(T)).