Emticicia oligotrophica gen. nov., sp nov., a new member of the family 'Flexibacteraceae', phylum Bacteroidetes

An aquatic bacterium, strain GPTSA100-15(T), was isolated on nutritionally poor medium TSBA100 (tryptic soy broth diluted 100 times and solidified with 1.5% agarose) and characterized using a polyphasic approach. The isolate was unable to grow on commonly used nutritionally rich media such as tryptic soy agar, nutrient agar and Luria-Bertani agar. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate was affiliated with the family 'Flexibacteraceae' in the phylum Bacteroidetes. Phylogenetically, it showed closest similarity (94-0%) with an uncultured bacterial clone, HP1A92, detected in a sludge microbial community. Among the culturable bacteria, the isolate had highest 16S rRNA gene sequence similarity with Leadbetterefla byssophila 4M15(T) (87-8%). Sequence similarities with other members of the phylum Bacteroidetes were less than 85%. The fatty acid profile of the isolate grown on TSBA100 indicated that the major fatty acid was iso-C15:0, which is also present in many members of the family 'Flexibacteraceae'. Cells of strain GPTSA100-15(T) are Gram-negative, strictly aerobic rods. The DNA G+C content of the isolate is 36.9 mol%. Results of phenotypic, chemotaxonomic and phylogenetic analyses clearly indicate that strain GPTSA100-15(T) represents a new genus within the family 'Flexibacteraceae'; the name Emticicia gen. nov. is proposed for the genus, with Emticicia oligotrophica sp. nov. as the type species. The type strain of Emticicia oligotrophica is GPTSA100-15(T) (=MTCC 6937(T) =DSM 17448(T)).