Marixanthomonas Spongiae Sp. Nov., Isolated From Marine Sponge

A novel bacterial strain, designated as HN-E44(T), was isolated from marine sponge collected from Yangpu Bay, Hainan, PR China. Strain HN-E44(T) was Gram-stain-negative, non-motile, catalase-positive. oxidase-negative. rod-shaped and yellow-pigmented. Growth occurred at 4-37 degrees C (optimum, 28 degrees C), at pH 6-8 (pH 7) and in 0.5-14% (w/v) NaCl (3-5%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain HN-E44(T) formed an independent cluster with Marixanthomonas ophiurae JCM 14121(T) within the family Flavobacteriaceae and had the highest sequence similarity of 93.6% to the closest type strain M. ophiurae JCM 14121(T). The major fatty acids were iso-C-15:0, anteiso-C-15:0, iso-C-17:0 3-OH, summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 6c and isoC(15:1) G. The polar lipids comprised phosphatidylethanolamine, sphingolipid, four unidentified phospholipids, an unidentified aminophospholipid and an unidentified lipid. The respiratory quinone was identified as MK-6. The genomic DNA G+C content was determined to be 40.6 mol%. The average nucleotide identity (ANI) and average amino acid identity (AAI) values between strain HN-E44(T) and closest type strain M. ophiurae JCM 14121(T) were, respectively, 79.6 and 85.2%, both of which were below thresholds for species delineation (95-96% ANI and 95-96% AAI), but were over thresholds for genus delineation (73.98% ANI and 70-76% AAI). The combined genotypic and phenotypic distinctiveness demonstrated that strain HN-E44(T) could be differentiated from closely related genera. Therefore, it is proposed that strain HN-E44(T) represents a novel species of the genus Marixanthomonas, for which the name Marixanthomonas spongiae sp. nov. is proposed, with the type strain HN-E44(T) (=MCCC 1K03332(T)=LMG 30459(T)).