Halomonas caseinilytica sp. nov., a halophilic bacterium isolated from a saline lake on the Qinghai-Tibet Plateau, China.

A halophilic, Gram-negative bacterial strain, designated AJ261T, which was isolated from a soil sample from a salt lake on the Qinghai-Tibet Plateau, was subjected to a polyphasic taxonomic study. The isolate grew optimally in the presence of 3-5 % NaCl and used various carbohydrates as sole carbon and energy sources. The genomic DNA G+C content was 63.0 mol%. The predominant fatty acids were C18 : 1omega7c, C16 : 0 and C12 : 0. A phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate had the highest sequence similarity with respect to type strains of Halomonas elongata (98.2 %), Halomonas eurihalina (98.1 %) and Halomonas halmophila (97.2 %). The DNA-DNA relatedness of strain AJ261T with respect to H. elongata NBRC 15536T, H. eurihalina CGMCC 1.2318T and H. halmophila DSM 5349T was 42, 25 and 26 %, respectively. Overall, the phenotypic, genotypic and phylogenetic results demonstrate that strain AJ261T represents a novel species within the genus Halomonas, for which the name Halomonas caseinilytica is proposed. The type strain is AJ261T (=CGMCC 1.6773T =JCM 14802T).