Hyphobacterium marinum sp. nov. and Hyphobacterium lacteum sp. nov., isolated from marine sediment

Two bacterial strains, Y60-23 T and HN-65 T , were isolated from marine sediment samples collected from Xiaoshi Island, Weihai, and Dongzhai Harbour, Haikou, PR China, respectively. Based on the 16S rRNA gene sequences, strain Y60-23 T exhibited 96.0% similarity to its most related type strain Hyphobacterium vulgare KCTC 52487 T , while strain HN-65 T exhibited 97.3% similarity to its most related type strain Hyphobacterium indicum 2ED5 T . The 16S rRNA gene sequence similarity between the two strains was 95.8%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains Y60-23 T and HN-65 T belonged to the genus Hyphobacterium . Cells of strains Y60-23 T and HN-65 T were rod-shaped, Gram-stain-negative, aerobic, non-motile, prosthecate and multiplied by binary fission. The major cellular fatty acids (>10.0%) of strain Y60-23 T were C 18 : 1 ω 7 c and C 17 : 0 , while those of strain HN-65 T were iso-C 17 : 1 ω 9 c , iso-C 17 : 0 and C 18 : 1 ω 7 c . The major respiratory quinone in both strains was ubiquinone-10 (Q-10) and the major polar lipids were monoglycosyl diglyceride, sulfoquinovosyl diacylglycerol and glucuronopyranosyl diglyceride. The genomic DNA G+C contents of strains Y60-23 T and HN-65 T were 63.9 and 60.7 mol%, respectively. The average nucleotide identity value between the two strains was 72.1% and the DNA–DNA hybridization value was 18.4%, clearly distinguishing them from each other. According to the results of the phenotypic, chemotaxonomic, phylogenetic and genomic analyses, the two strains represented two novel species within the genus Hyphobacterium , for which the names Hyphobacterium marinum sp. nov. and Hyphobacterium lacteum sp. nov. were proposed with the type strains Y60-23 T (=MCCC 1H01433 T =KCTC 8172 T ) and HN-65 T (=MCCC 1H01434 T =KCTC 8169 T ), respectively.