Halomonas socia sp. nov., isolated from high salt culture of Dunaliella salina.

A moderately halophilic bacteria designed strain NY-011(T) was isolated from the high salt culture of Dunaliella salina in Chengdu of Sichuan Province, China. The isolate was Gram-negative, nonmotile, rod-shaped and 12.5-21.6 μm in length. Colonies on solid media are circular, wet, smooth and cream. The strain grew optimally at 37 °C, pH 7.0 and in the presence of 8 % NaCl. Acid was produced from glycerol, D-arabinose, glucose, trehalose, inositol, mannose, mannitol, sucrose, maltose and sorbitol. Catalase is produced but not oxidase. The major fatty acids are C18: 1ω7c (37.59 %), C19: 0 cyclo ω8c (18.29 %), C16: 0 (16.05 %) and C6: 0 (12.43 %). The predominant respiratory lipoquinone found in strain NY-011(T) is ubiquinone with nine isoprene units (Q-9). The genomic DNA G + C content of strain NY-011(T) was 62.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NY-011(T) belonged to the genus Halomonas. The highest levels of 16S rRNA gene sequence similarity were found between the strain NY-011(T) and H. pantelleriensis (sequence similarity 98.43 %). However, the levels of DNA-DNA relatedness between them were only 23.1 %. In addition, the strain NY-011(T) had a phenotypic profile that readily distinguished it from H. pantelleriensis. The strain NY-011(T) therefore represents a new species of the genus Halomonas, for which the name Halomonas socia sp. nov. is proposed, with NY-011(T) (=CCTCC AB 2011033(T) = KCTC 23671(T)) as the type strain.