Oceanobacillus oncorhynchi sp. nov., a halotolerant obligate alkaliphile isolated from the skin of a rainbow trout (Oncorhynchus mykiss), and emended description of the genus Oceanobacillus

A halotolerant, obligately alkaliphilic bacterium, R-2^T, was isolated from the skin of a rainbow trout (Oncorhynchus mykiss), a freshwater fish. The strain is Gram-positive, ferments several carbohydrates, is rod-shaped and motile by peritrichous flagella and produces ellipsoidal spores. The isolate grows at pH 910 but not at pH 78. This micro-organism grows in 022 % (w/v) NaCl at pH 10. Its major cellular fatty acids are iso-C_{15 : 0}, anteiso-C_{15 : 0} and anteiso-C_{17 : 0}, the major isoprenoid quinone is MK-7 and the DNA G+C content is 38·5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicates that strain R-2^T is a member of the genus Oceanobacillus. DNADNA hybridization reveals low relatedness between the isolate and Oceanobacillus iheyensis (21·0 %). On the basis of phenotypic characteristics, phylogenetic data and DNADNA relatedness data, the isolate should be designated as a novel species, for which the name Oceanobacillus oncorhynchi sp. nov. is proposed. The type strain is R-2^T (=JCM 12661^T=NCIMB 14022^T).