Vibrio ouci sp. nov. and Vibrio aquaticus sp. nov., two marine bacteria isolated from the East China Sea

Two Gram-stain-negative, catalase- and oxidase-positive, facultative anaerobic and rod-shaped motile bacteria, designated strains BEI176 T and BEI207 T , were isolated from seawater collected in the East China Sea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains BEI176 T and BEI207 T belonged to the genus Vibrio and were closely related to each other with 98.18 % similarity. The closest phylogenetic relatives of strain BEI176 T were Vibrio alginolyticus LMG 4409 T (98.85 %) and Vibrio campbellii LMG 11216 T (98.81 %), whereas the closest relative of strain BEI207 T was Vibrio hepatarius LMG 20362 T (98.64 %). The two strains showed growth at different conditions; while strain BEI176 T grew at 16-37 °C, pH 5.0-9.5 and 0-7.0 % (w/v) NaCl, the growth of strain BEI207 T occurred at 10-37 °C, pH 6.0-9.5 and 1.0-7.0 % (w/v) NaCl. Both strains shared the same major fatty acid components of summed feature 3 (C 16 : 1 ω7 c or C 16 : 1 ω6 c ), C 16 : 0 and summed feature 8 (C 18 : 1 ω6 c or C 18 : 1 ω7 c ). The DNA G+C contents of the assembled genomic sequences were 44.73 and 45.06 mol% for strains BEI176 T and BEI207 T , respectively. Average nucleotide identity values between the two strains and their reference species were lower than the threshold for species delineation (95-96 %); in silico DNA-DNA hybridization further showed that the two strains had less than 70 % similarity to their relatives. Therefore, two novel Vibrio species are proposed to accommodate them: Vibrioouci sp. nov. (type strain, BEI176 T =MCCC 1K03515 T =JCM 32690 T = KCTC 62616 T ) and Vibrioaquaticus sp. nov. (type strain, BEI207 T =MCCC 1K03516 T =JCM 32691 T =KCTC 62617 T ).