Halobacillus profundi sp nov and Halobacillus kuroshimensis sp nov., moderately halophilic bacteria isolated from a deep-sea methane cold seep

Two Gram-positive, rod-shaped, moderately halophilic bacteria were isolated from a deep-sea carbonate rock at a methane cold seep in Kuroshima Knoll, Japan. These bacteria, strains IS-Hb4(T) and IS-Hb7(T), were spore-forming and non-motile. They were able to grow at temperatures as low as 9 degrees C and hydrostatic pressures up to 30 MPa. Based on high sequence similarity of their 16S rRNA genes to those of type strains of the genus Halobacillus, from 96.4 % (strain IS-Hb7(T) to Halobacillus halophilus NCIMB 9251(T)) to 99.4 % (strain IS-Hb4(T) to Halobacillus dabanensis D-8(T)), the strains were shown to belong to this genus. DNA-DNA relatedness values of 49.5 % and 1.0-33.0 %, respectively, were determined between strains IS-Hb4(T) and IS-Hb7(T) and between these strains and other Halobacillus type strains. Both strains showed the major menaquinone MK7 and L-Orn-D-Asp cell-wall pepticloglycan type. Straight-chain C-16:0, unsaturated C-16:1 omega 7c alcohol and C-18:1 omega 7c and cyclopropane C-19:0 cyc fatty acids were predominant in both strains. The DNA G + C contents of IS-Hb4(T) and IS-Hb7(T) were respectively 43.3 and 42.1 mol%. Physiological and biochemical analyses combined with DNA-DNA hybridization results allowed us to place strains IS-Hb4(T) (= JCM 14154(T) =DSM 18394(T)) and IS-Hb7(T) (= JCM 14155(T) = DSM 18393 T) in the genus Halobacillus as the respective type strains of the novel species Halobacillus profundi sp. nov. and Halobacillus kuroshimensis sp. nov.