Hydrotalea flava gen. nov., sp. nov., a new member of the phylum Bacteroidetes and allocation of the genera Chitinophaga, Sediminibacterium, Lacibacter, Flavihumibacter, Flavisolibacter, Niabella, Niastella, Segetibacter, Parasegetibacter, Terrimonas, Ferruginibacter, Filimonas and Hydrotalea to the family Chitinophagaceae fam. nov.

Three bacterial strains, designated CCUG 51397(T), CCUG 53736 and CCUG 53920, isolated from water samples taken at different locations in southern Sweden were studied to determine their taxonomic position using a polyphasic approach. Comparative analysis of 16S rRNA gene sequences showed that these bacteria had <93 % sequence similarity to all described species of the genera Sediminibacterium, Lacibacter, Flavihumibacter, Flavisolibacter, Niabella, Niastella, Segetibacter, Parasegetibacter, Terrimonas, Ferruginibacter, Filimonas and Chitinophaga. The three organisms grouped most closely with Sediminibacterium salmoneum NJ-44(T) but showed only 92.5 % sequence similarity to this strain, the only recognized species of this genus. The fatty acid profiles showed large amounts of iso-C₁₅:₀, iso-C₁₇:₀ 3-OH and iso-C₁₅:₁ G with smaller amounts of iso-C₁₅:₀ 3-OH, iso-C₁₆:₀ 3-OH and other fatty acids, which differentiated the novel strains from related genera. Biochemical tests performed on strains CCUG 51397(T), CCUG 53736 and CCUG 53920 also gave different results from those of Sediminibacterium salmoneum NJ-44(T) and other related genera. Based on this evidence, strains CCUG 51397(T), CCUG 53736 and CCUG 53920 represent a novel species of a new genus, for which the name Hydrotalea flava gen. nov., sp. nov. is proposed. The type strain of Hydrotalea flava is CCUG 51397(T) (=CCM 7760(T)). A formal allocation of the genera Sediminibacterium, Lacibacter, Flavihumibacter, Flavisolibacter, Niabella, Niastella, Segetibacter, Parasegetibacter, Terrimonas, Ferruginibacter, Filimonas and Chitinophaga to the family Chitinophagaceae fam. nov. is also proposed.