Halomonas sambharensis sp. nov., a Moderately Halophilic Bacterium Isolated from the Saltern Crystallizer Ponds of the Sambhar Salt Lake in India

摘要

Two moderately halophilic strains SBS 10(T) and SSO 06 were isolated from the saltern crystallizer ponds of the hypersaline Sambhar Salt Lake in India. Strains were aerobic, Gram-stain-negative, and rod shaped. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that two strains belong to the genus Halomonas in the Gammaproteobacteria, with highest 16S rRNA gene sequence similarities with Halomonas gudaonensis LMG 23610(T) (98.2% similarity) and Halomonas campaniensis 5AG(T) (99.0% similarity). Strains grew optimally at 37 degrees C, pH 7.5-8.0 in the presence of 5-8% (w/v) NaCl. The major fatty acids of the strain SBS 10(T) were C-18:1 omega 7c (54.37%), C-16:0 (25.69%), C-16:1 x 7c/C-16:1 x 6c (13.28%), and C-12:0 (1.21%). The G+C content was 63.6 mol % (T-m). Phenotypic features, fatty acids profile, and DNA G+C content supported placement of the strain SBS 10(T) in the genus Halomonas having distinct characteristics with related strains. Analysis of the housekeeping genes: gryB and rpoD and in silico DNA-DNA hybridization between the strain SBS 10(T) and its type strain Halomonas gudaonensis (LMG 23610(T)) further revealed the strain SBS 10(T) to be a distinct species. On the basis of the phenotypic, chemotaxonomic and phylogenetic analysis, the strain SBS 10(T) is considered to represent a novel species for which the name Halomonas sambharensis is proposed. The type strain is SBS 10(T) (= MTCC 12313(T) = LMG 30344(T)).