Vibrio algicola sp. nov., isolated from the surface of coralline algae

A Gram-stain-negative, oxidase- and catalase-positive, facultative anaerobic and rod-shaped bacterium, designated strain SM1977^T, was isolated from the surface of coralline algae collected from the intertidal zone at Qingdao, PR China. The strain grew at 10-35 °C, pH 4.5-8.5 and with 1-8.5% (w/v) NaCl. It reduced nitrate to nitrite and hydrolysed Tween 20 and DNA. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SM1977^T was affiliated with the genus Vibrio, having the highest sequence similarity (97.6 %) to the type strain of Vibrio casei, followed by those of another five species (95.6-97.6 %) in the Rumoiensis clade of the genus Vibrio. However, the in silico DNA-DNA hybridization (75.3-75.9 %) and average nucleotide identity (21.6-22.8 %) values of SM1977^T against these close relatives were all below the corresponding thresholds to discriminate bacterial species. The major fatty acids were summed feature 3 (C_16:1  ω7c and/or C_16:1  ω6c), C_16:0 and summed feature 8 (C_18:1  ω6c and /or C_18:1  ω7c). The predominant polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The sole respiratory quinone was Q-8. The genomic DNA G+C content of strain SM1977^T, determined from the obtained whole genomic sequence, was 42.3 mol%. On the basis of the polyphasic results obtained in this study, strain SM1977^T is considered to represent a novel species within the genus Vibrio, for which the name Vibrio algicola sp. nov. is proposed. The type strain is SM1977^T (=MCCC 1K04351^T=KCTC 72847^T).