Oceanobacillus aidingensis sp. nov., a moderately halophilic bacterium

Two Gram-positive, rod-shaped moderately halophilic bacterial strains, designated AD7-25(T) and AB-11, were isolated from Aiding and Manasi salt lakes in Xinjiang of China, respectively. The strains were found to be able to grow at NaCl concentrations of 0-21 % (w/v), with optimum growth occurring at 6-8 % (w/v) NaCl. The optimal temperature and pH for growth were determined to be 33-37 °C and pH 7.0-7.5. Cells of the strains are motile by means of polar flagella. Both strains can produce ellipsoidal spores. The major cellular fatty acids were identified as anteiso-C15:0, iso-C15:0, iso-C14:0, anteiso-C17:0 and iso-C16:0. The diamino acid in the peptidoglycan and the major quinone system were determined to be meso-diaminopimelic acid (meso-DAP) and MK-7, respectively. The DNA G+C contents of stains AD7-25(T) and AB-11 were 39.8 and 40.0 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that these two novel strains are closely related to the genus Oceanobacillus showing 90-99.5 % similarity with respect to type strains. These two novel strains were most closely related to Oceanobacillus oncorhynchi subsp. incaldanensis DSM 16557(T) (99.1 and 99.5 %), followed by O. oncorhynchi subsp. oncorhynchi JCM 12661(T) (99.1 and 99.4 %), Oceanobacillus neutriphilus CGMCC 1.7693(T) (97.0 and 97.5 %), Oceanobacillus sojae JCM 15792(T) (97.6 and 98.0 %) and Oceanobacillus locisalsi KCTC 13253(T) (96.5 and 96.9 %). The DNA-DNA hybridization data indicated that DNA relatedness between strains AD7-25(T) and AB-11 was 91.0 %, and the genomic homology of representative strain AD7-25(T) with O. oncorhynchi subsp. incaldanensis DSM 16557(T), O. oncorhynchi subsp. oncorhynchi JCM 12661(T), O. neutriphilus CGMCC 1.7693(T), O. sojae JCM 15792(T) and O. locisalsi KCTC 13253(T) were 41, 39, 20, 23 and 17 %, respectively. On the basis of phenotypic and phylogenetic distinctiveness, strains AD7-25(T) and AB-11 should be assigned to the genus Oceanobacillus as a new species, for which the name Oceanobacillus aidingensis sp. nov. was proposed. The type strain is AD7-25(T) (=CGMCC 1.9106 (T) = NBRC 105904(T)).