Poritiphilus flavus gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from coral Porites lutea

A novel Gram-stain-negative, non-endospore-forming, non-motile, aerobic bacterium (strain R33 T ) was isolated from coral Porites lutea and subjected to a polyphasic taxonomic study. The G+C content was 44.5 mol%. The only detected respiratory quinone was menaquinone 6 (MK-6). The major cellular fatty acids were iso-C 15 : 0 and iso-C 15 : 1  ω6 c . The major polar lipids were phosphatidylethanolamine and two unidentified lipids. Global alignment based on 16S rRNA gene sequences indicated that strain R33 T shares the highest sequence identity of 93.2 % with Muriicola marianensis A6B8 T in the family Flavobacteriaceae . Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R33 T forms a distinct branch in a stable clade comprising strain R33 T and members of the genera Muriicola , Robiginitalea , Eudoraea and Zeaxanthinibacter . The phylogenomic analysis also supported this 16S rRNA gene-based phylogenetic result. Comparative genomic analysis indicated that strain R33 T is rich in AraC-type DNA-binding domain-containing protein-coding genes, which means the regulation of carbon utilization is very complex. Low 16S rRNA gene identity, different polar lipids and/or cellular fatty acid profiles could readily distinguish strain R33 T from any validly published type strains. Therefore, strain R33 T is suggested to represent a new species in a new genus, for which the name Poritiphilus flavus gen. nov., sp. nov. is proposed. The type strain is R33 T (=MCCC 1K03853 T =KCTC 72443 T ).