Salinisphaera orenii sp. nov., isolated from a solar saltern.

A taxonomic study was performed on two isolates, designated strains MK-B5(T) and MK-B7, isolated from sediment of a solar saltern pond in Gomso Bay, Republic of Korea. Comparative 16S rRNA gene sequence analysis showed that strains MK-B5(T) and MK-B7 belong to the Gammaproteobacteria and are related most closely to Salinisphaera shabanensis JCM 11575(T) ( = E1L3A(T)) (96.3 and 96.5% similarity, respectively), Salinisphaera dokdonensis KCCM 90064(T) ( = CL-ES53(T)) (95.6 and 95.6%) and Salinisphaera hydrothermalis JCM 115514(T) ( = EPR70(T)) (95.1 and 95.3%). The level of 16S rRNA gene sequence similarity between strains MK-B5(T) and MK-B7 was 99.8%. The G+C contents of their genomic DNAs were 63.4 and 63.6 mol%, respectively, and the major respiratory quinone was ubiquinone-8. DNA-DNA relatedness between strains MK-B5(T) and MK-B7 was 98%, indicating that the two isolates represent a single species. However, the level of DNA-DNA relatedness between the two isolates and S. shabanensis E1L3A(T) (26.4-30.8%) indicates that they represent a novel species. Strains MK-B5(T) and MK-B7 possessed C(14:0), C(16:0) and C(19:0)ω8c cyclo as major fatty acids. The two isolates were Gram-stain-negative, strictly aerobic, short rod-shaped and motile. They grew at 10-40 °C (optimum, 35-37 °C), at pH 5.0-8.5 (optimum, 7.0-7.5) and with 5-25% (w/v) NaCl (optimum, 15% NaCl). On the basis of phenotypic and phylogenetic analyses, strains MK-B5(T) and MK-B7 are thus considered to represent a novel species of the genus Salinisphaera, for which the name Salinisphaera orenii sp. nov. is proposed. The type strain is MK-B5(T) ( = KCTC 23198(T) = JCM 17073(T)).