A Gram-stain-negative, aerobic, non-motile and ovoid or rod-shaped bacterial strain, designated OITF-44T, was isolated from a tidal flat in Oido, an island of the Republic of Korea. Strain OITF-44T grew optimally at 25 °C and in the presence of 2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences revealed that strain OITF-44T formed an independent lineage within the clade comprising the genera Lutimonas, Taeania, Actibacter and Namhaeicola. The novel strain exhibited 16S rRNA gene sequence similarity values of 93.9-95.7 % to the type strains of the species of the genera Lutimonas, Taeania, Actibacter and Namhaeicola, and of less than 93.5 % to the type strains of other recognized species. Strain OITF-44T contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C15 : 1 G, iso-C16 : 1 H and iso-C16 : 0 3-OH as the major fatty acids. The major polar lipids of strain OITF-44T were phosphatidylethanolamine, one unidentified lipid and one unidentified phospholipid. The DNA G+C content of strain OITF-44T was 33.9 mol%. The chemotaxonomic data and other differential phenotypic properties made it reasonable to distinguish strain OITF-44T from the type strains of the type species of the genera Lutimonas, Taeania, Actibacter and Namhaeicola. On the basis of the data presented here, strain OITF-44T is considered to constitute a new genus and species within the family Flavobacteriaceae, for which the name Aestuariimonas insulae gen. nov., sp. nov. is proposed. The type strain of Aestuariimonas insulae is OITF-44T (=KACC 19569T=KCTC 62197T=DSM 105891T=NBRC 113118T).
Keywords: Aestuariimonas insulae; novel genus; novel species; polyphasic taxonomy; tidal flat sediment.