Aestuariibaculum suncheonense gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from a tidal flat and emended descriptions of the genera Gaetbulibacter and Tamlana T was observed at 5-40 6C (optimum, 25-30 6C), at pH 6.0-8.5 (optimum, pH 7.0) and in the presence of 1-8 % (w/v) NaCl (optimum, 1-2 %). The major cellular fatty acids were iso-C 15 : 0 , summed feature 3 (comprising C 16 : 1 v7c and/or C 16 : 1 v6c and/or iso-C 15 : 0 2-OH), iso-C 17 : 0 3-OH, iso-C 15 : 1 G and anteiso-C 15 : 0. The polar lipid content consisted of phosphatidylethanolamine and unidentified amino lipids and lipids. The G+C content of the genomic DNA was 46.4 mol% and the only respiratory quinone detected was menaquinone-6 (MK-6). Phylogenetic inference based on 16S rRNA gene sequences showed that strain SC17T formed a distinct phyletic lineage within the family Flavobacteriaceae and was most closely related to members of the genera Gaetbulibacter and Tamlana with 95.0-95.8 % sequence similarity. On the basis of phenotypic and molecular features, strain SC17 T represents a novel genus of the family Flavobacteriaceae, for which the name Aestuariibaculum suncheonense gen. nov., sp. nov. is proposed. The type strain is SC17 T (5KACC 16186 T 5JCM 17789 T ). Emended descriptions of the genera Gaetbulibacter and Tamlana are also proposed.The families Flavobacteriaceae, Bacteroidaceae, Cryomorphaceae, Cytophagaceae, Chitinophagaceae and Sphingobacteriaceae consist of very diverse taxa and they are affiliated with the different classes of the phylum Bacteroidetes: the class Flavobacteriia (families Flavobacteriaceae and Cryomorphaceae), the class Bacteroidia (family Bacteroidaceae), the class Cytophagia (family Cytophagaceae) and the class Sphingobacteriia (families Chitinophagaceae and Sphingobacteriaceae) (Ludwig et al., 2010). The family Flavobacteriaceae contains Gram-stain-negative, rod-shaped, chemoheterotrophic bacteria that are non-motile or motile by gliding and contain menaquinone-6 (MK-6) as the major isoprenoid quinone (Bernardet et al., 2002;Bowman & Nichols, 2005;Bernardet & Nakagawa, 2006;Bernardet, 2011). Currently, the family Flavobacteriaceae consists of more than 90 genera with validly published names. Sea tidal flats are broad, plain marshes with low-gradients, or muddy coast areas that experience exposure and flooding by seawater between low and high tides. The west and south-west coast of the Korean peninsula largely consists of sea tidal flats, called getbol, that contain a wealth of valuable biological resources such as micro-organisms and marine animals. Recently, numerous microbial species have been isolated from sea tidal flats. Therefore, efforts have been made in our laboratory to isolate and characterize marine bacteria from sea tidal flats (Jin et al., 2011a, b;Jung et al., 2011;Lee et al., 2011;Park et al., 2011).In the course of this study, a novel yellow-pigmented, Gramstaining-negative, rod-shaped bacterium was isolated. Here, we describe its taxonomic characterization and pro...