Vibrio sagamiensis sp. nov., luminous marine bacteria isolated from sea water.

Two novel marine luminous bacteria, LC2-047T and LC1-908, were isolated from seawater in Sagami Bay in Japan and an equatorial area, respectively. The cells are Gram-negative, rod shaped and motile with one polar flagellum. These bacteria are oxidase-positive and catalase-positive, and are able to grow in 0.5‒6% NaCl (optimum 3‒5%) and at temperatures of 10‒37°C (optimum 25‒30°C). Phylogenetic analysis based on 16S rRNA gene sequences indicated that these bacteria were closely related to Vibrio azureus (99.4% sequence similarity) and Vibrio parahaemolyticus (99.3%). DNA‒DNA hybridization demonstrated that LC2-047T and LC1-908 were conspecific and clearly separated from the closest relative with less than 60% DNA‒DNA hybridization similarity. Multilocus sequence analysis (MLSA) using six loci (gyrB, pyrH, gapA, ftsZ, mreB, and recA) showed that these bacteria are included in the Harvey clade. Additionally, these strains differ from the closest related Vibrio species by the utilization of glucose, mannitol, inositol, sucrose and amygdalin and production of esterase (C4), lipase (C4) and acid phosphatase. The major fatty acids are C15:0 iso 2-OH and/or C16:1ω7c, C16:0, C18:1ω7c, C14:0, C15:0, C17:1ω8c and C12:0. The DNA G+C content of LC2-047T and LC1-908 were 43.8 and 43.7 mol%, respectively. On the basis of the polyphasic taxonomic evidence presented in this study, it is concluded that strains LC2-047T and LC1-908 belong to the same genospecies and represent a novel species of the genus Vibrio, for which the name Vibrio sagamiensis sp. nov. is proposed. The type strain is LC2-047T (=NBRC 104589T = KCTC 22354T). The family Vibrionaceae includes six genera: Vibrio (Baumann and Schubert, 1984), Photobacterium (Baumann and Baumann, 1984), Salinivibrio (Mellado et al., 1996), Grimonita (Thompson et al., 2003a), Enterovibrio (Thompson et al., 2002) and Aliivibrio (Urbanczyk et al., 2007). Several species of the genus Vibrio are ubiquitous in aquatic environments, especially in the ocean, and are often isolated from various organisms ranging from plankton to fish (Thompson et al., 2003b). A recent molecular biological technique based on Multilocus sequence analysis (MLSA) showed that genus Vibrio comprises 14 distinct clades: Anguillarum, Cholerae, Coralliilyticus, Diazotrophicus, Gazogenes, Fischeri, Halioticoli, Harveyi, Nereis, Nigripulchritudo, Orientalis, Scopthalmi, Splendidus and Vulnifi cus (Sawabe et al., 2007). Now Fischeri clade is regarded as genus J. Gen. Appl. Microbiol., 56, 499‒507 (2010)