Oceanibaculum nanhaiense sp. nov., isolated from surface seawater.

A taxonomic study was carried out on strain L54-1-50, which was isolated from surface seawater of the South China Sea. Cells of strain L54-1-50 were Gram-stain-negative, rod-shaped, oxidase-positive and catalase-positive. Growth was observed at salinities from 0 to 9 % (optimum 2 %, w/v), at pH 6.0-10.0 (optimum 8.0-9.0) and at temperatures from 10 to 45 °C (optimum 25-37 °C), but not at 4 or 50 °C. The 16S rRNA gene sequence analysis indicated that strain L54-1-50 was a member of the genus Oceanibaculum, related to Oceanibaculum indicum P24 (98.8 %) and Oceanibaculum pacificum MC2UP-L3 (97.7 %). The digital DNA-DNA hybridization values between strain L54-1-50 and the two type strains O. indicum P24 and O. pacificum MC2UP-L3 were 35.4±2.5 and 23.7±2.5 %, respectively. The average nucleotide identity values between strain L54-1-50 and two type strains were 79.7 and 88.3 %, respectively. The major cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C16 : 0 and C18 : 1 2-OH. The respiratory quinone was Q-10. The polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, two unidentified phospholipids and three unidentified lipids. The G+C content of the chromosomal DNA was 65.1 mol%. The combined genotypic and phenotypic data showed that strain L54-1-50 represents a novel species of the genus Oceanibaculum, for which the name Oceanibaculumnanhaiense sp. nov. is proposed, with the type strain L54-1-50 (=KCTC 52312=MCCC 1A05150).