Halomonas daqiaonensis sp nov., a moderately halophilic, denitrifying bacterium isolated from a littoral saltern

Two novel Gram-negative, oxidase- and catalase-positive, rod-shaped bacterial strains, designated YCSA28(T) and YCSA39, were isolated from sediment of Daqiao saltern, Jimo, Qingdao, on the east coast of China. The two strains grew optimally at 28-30 degrees C, at pH 7.5 and in the presence of 7-8% (w/v) NaCl. They were assigned to the genus Halomonas, class Gammaproteobacteria, based on 16S rRNA gene sequence analysis. The major cellular fatty acids of the two strains were C-18:1 omega 7c (42.9%), C-16:0 (23.1 %) and C-16:1 omega 7c/omega 6c (18.0%), and Q-9 was the major ubiquinone. The G+C content of the DNA of strains YCSA28(T) and YCSA39 was 63.7 and 63.9 mol%, respectively. The predominant respiratory lipoquinone, cellular fatty acid profiles and DNA G+C content of strains YCSA28(T) and YCSA39 were consistent with those of recognized species of the genus Halomonas. Levels of DNA DNA relatedness between strains YCSA28(T) and YCSA39, between YCSA28(T) and Halomonas ventosae Al12(T), and between YCSA39 and H. ventosae Al12(T) were 95, 45 and 50%, respectively. Together, these data indicated that strains YCSA28(T) and YCSA39 represent a single novel species of the genus Halomonas, for which the name Halomonas daqiaonensis sp. nov. is proposed. The type strain is YCSA28(T) (=CGMCC 1.9150(T) =NCCB 100305(T) =MCCC 1B00920(T)).