Yeosuana marina sp. nov., isolated from shallow-sea hydrothermal systems off Kueishantao Island

A novel Gram-stain-negative, non-flagellated, non-motile, rod-shaped (0.4-0.6x1.8-2.5 mu m), aerobic bacterial strain, designated JLT21(T), was isolated from seawater of a shallow-sea hydrothermal system. Growth occurred with 0-4.0 % (w/v) NaCl (optimum, 2.0 % NaCl), at 8-45 degrees C (optimum, 25 degrees C) and at pH 3.0-10.0 (optimum, pH 7.0). Analysis of 16S rRNA gene sequences revealed that strain JLT21(T) showed the highest 16S rRNA gene sequence similarity to Gaetbulibacter aquiaggeris KEM-8T (97.2 %), Gaetbulibacter marinus IMCC1914(T) (96.9 %) and Yeosuana aromativorans GW1-1(T) (96.9 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain JLT21(T) clustered with Y. aromativorans GW1-1(T). The predominant respiratory quinone of strain JLT21(T) was menaquinone-6 (MK-6). Polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, three unidentified glycolipids and four unidentified lipids. The major fatty acids of strain JLT21(T) were iso-C-15:0 (21.7 %), C-16:1 omega 6c/omega 7c (11.5 %) and iso-C-17:0 3-OH (10.9 %). The DNA G+C content of strain JLT21(T) was 32.6 %. On the basis of polyphasic analysis, strain JLT21(T) is considered to represent a novel species of the genus Yeosuana, for which the name Yeosuana marina sp. nov. is proposed. The type strain of Yeosuana marina is JLT21(T) (=CGMCC 1.15787(T)=JCM 31511(T)). The study helps us better understand the bacterial species in the shallow-sea hydrothermal system and their adaptations to the hydrothermal environment.