Arenibacter Aquaticus Sp. Nov., A Marine Bacterium Isolated From Surface Sea Water In The South China Sea

A Gram-stain-negative and facultatively anaerobic bacterial strain, designated GUO(T), was isolated from surface water collected from the South China Sea. Cells were non-flagellate, yellow, non-spore-forming and rod-shaped. The 16S rRNA gene sequence comparisons with species in the genus Arenibacter showed that strain GUO(T) shares the highest similarity of 97.5% with Arenibacter echinorum and Arenibacter palladensis. Average nucleotide identity and digital DNA-DNA hybridization values between strain GUO(T) and its related type strains were 77.1-78.4% and 20.8-26.2% respectively. Growth of strain GUO(T) occurred at 15-50 degrees C (optimum, 20-25 degrees C), pH 5-7.5 (pH 6) and in media containing 0-7% NaCl (optimum, 0-1%). Cells contained methanolsoluble yellow-coloured pigments but flexirubin-type pigments were absent. The major fatty acids (>5%) were iso-C-17:0 3-OH, anteiso-C-15:0, C-16:0, summed feature 3, iso-C-15:1 G and iso-C-15:0 3-OH. The dominant polar lipids comprised phosphatidylethanolamine and some unidentified polar lipids. The main respiratory quinone was menaquinone-6. The DNA G+C content of strain GUO(T) was 40.1%. Based on the presented data, we consider strain GUO(T) to represent a novel species of the genus Arenibacter, for which the name Arenibacter aquaticus sp. nov. is proposed. The type strain is GUO(T) (=KCTC 62629(T)=MCCC 1K03559(T)).