Exilibacterium tricleocarpae gen. nov., sp. nov., a marine bacterium from coralline algae Tricleocarpa sp.

A Gram-stain-negative, non-spore-forming, aerobic, curved rod-shaped bacterium, designed strain R142(T), was isolated from a coralline algae Tricleocarpa sp. in the Beibu Gulf, China. Optimal growth occurred with 0-0.5% (w/v) NaCl, at 25 degrees C and at pH 8. Global alignment based on 165 rRNA gene sequences indicated that strain R142(T) shared 93.8% similarity with its closest type strain, Pseudomaricurvus alkylphenolicus KU14G(T). Phylogenetic analyses showed that strain R142(T) forms a distinct branch alongside Maricurvus nonylphenolicus KU41E(T), Pseudoteredinibacter isoporae SW-11(T) Pseudomaricurvus alkylphenolicus KU14G(T), Pseudomaricurvus alcaniphilus MEBiC06469(T) and Aestuariicella hydrocarbonica SM-6(T). The major polar lipids of strain R142(T) were phosphatidylethanolamine and phosphatidylglycerol. The primary cellular fatty acids were C-16:0, C-16:1 omega 7C, C-18:1 omega 7C, C-19:0 and C-14:0. The genome DNA G+C ratio was 56.4 mol%. The only detected respiratory quinone was ubiquinone 8. The low 165 rRNA gene sequence similarity and differences in cellular fatty acids readily distinguished strain R142(T) from all validly published type strains. Strain R142(T) is therefore suggested to represent a novel species of a new genus, for which the name Exilibacterium tricleocarpae gen. nov., sp. nov. is proposed. The type strain of Exilibacterium tricleocarpae is R142(T) (=MCCC 1K03816(T)=KCTC 72138(T)).