Vibrio japonicus sp. nov., a novel member of the Nereis clade in the genus Vibrio isolated from the coast of Japan

A novel Vibrio strain, JCM 31412(T), was isolated from seawater collected from the Inland Sea (Setonaikai), Japan, and characterized as a Gram-negative, oxidase-positive, catalase-negative, facultatively anaerobic, motile, ovoid-shaped bacterium with one polar flagellum. Based on 16S rDNA gene identity, strain JCM 31412(T) showed a close relationship with type strains of Vibrio brasiliensis (LMG 20546(T), 98.2% identity), V. harveyi (NBRC 15634(T), 98.2%), V. caribbeanicus (ATCC BAA-2122(T), 97.8%) and V. proteolyticus (NBRC 13287(T), 97.8%). The G+C content of strain JCM 31412(T) DNA was 46.8%. Multi-locus sequence analysis (MLSA) of eight loci (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA; 5535bp) further clustered strain JCM 31412(T) in the Nereis clade, genus Vibrio. Phenotypically, strain JCM 31412(T) differed from the closest related Vibrio species in its utilization of melibiose and raffinose, and its lack of casein and gelatin hydrolysis. It was further differentiated based on its fatty acid composition, specifically properties of C(12:0)3OH and summed features, which were significantly different from those of V. brasiliensis, V. nigripulchritudo and V. caribbeanicus type strains. Overall, the results of DNA-DNA hybridization, and physiological and biochemical analysis differentiated strain JCM 31412(T) from other described species of the genus Vibrio. Based on these polyphasic taxonomic findings, it was therefore concluded that JCM 31412(T) was a novel Vibrio species, for which the name Vibrio japonicus sp. nov. was proposed, with JCM 31412(T) (= LMG 29636(T) = ATCC TSD-62(T)) as the type strain.