Vibrio amylolyticus sp. nov. and Vibrio gelatinilyticus sp. nov., two marine bacteria isolated from surface seawater of Qingdao

Abstract

Two Gram-stain-negative, oxidase-positive, facultative anaerobic and rod-shaped motile bacteria, designated strains ZSDZ34 and ZSDE26, were isolated from offshore surface seawater collected near Qingdao. Phylogenetic analysis based on 16S rRNA gene sequences placed ZSDE26T and ZSDZ34T within the genus Vibrio , family Vibrionaceae , class Gammaproteobacteria . Strain ZSDE26T was most closely related to Vibrio gallaecicus VB 8.9T with 97.3 % sequence similarity, whereas ZSDZ34T was most closely related to Vibrio aestuarianus subsp. cardii DSM 109723T with 97.8 % sequence similarity. Strain ZSDE26T grew with 1–5 % (w/v) NaCl (optimum, 4 %), at 16–28 °C (optimum, 28 °C) and at pH 6.0–9.0 (optimum, pH 7.0). Growth of strain ZSDZ34T occurred with 1–6 % (w/v) NaCl (optimum, 3 %), at 16–37 °C (optimum, 28 °C) and at pH 6.0–9.0 (optimum, pH 7.0). Both strains shared the same major fatty acid components (more than 10 % of total fatty acids) of summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and C16 : 0. Additionally, strain ZSDZ34T contained a higher proportion of iso-C16 : 0. The DNA G+C contents of strains ZSDE26T and ZSDZ34T were 42.8 and 44.5 mol%, respectively. On the basis of the results of polyphasic analysis, ZSDE26T and ZSDZ34T are considered to represent novel species within the genus Vibrio , for which the names Vibrio amylolyticus sp. nov. (type strain, ZSDE26T=KCTC 82890T=MCCC 1K06290T) and Vibrio gelatinilyticus sp. nov. (type strain, ZSDZ34T=KCTC 82888T=MCCC 1K06292T) are proposed, respectively.