Flavobacterium aquidurense sp. nov. and Flavobacterium hercynium sp. nov., from a hard-water creek.

Ten new Flavobacterium-like strains were isolated from freshwater of the hard-water creek Westerhöfer Bach, northern Germany. These strains formed two phylogenetic groups: strains WB 1.1-56T, WB 1.1-04, WB 1.1-14, WB 1.1-57 and WB 1.1-63; and strains WB 4.2-33T, WB 4.1-86, WB 4.2-34, WB 4.2-32 and WB 4.2-78. Cells were Gram-negative, yellow-pigmented, chemoheterotrophic rods. Their major fatty acid profiles were similar, consisting of iso-C(15 : 0), iso-C(15 : 0) 3-OH, iso-C(17 : 0) 3-OH and summed feature 3 (C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH). DNA G+C contents for strains WB 1.1-56T and WB 4.2-33T were 33.5 and 37.5 mol%, respectively. Phylogenetic analysis based on almost complete 16S rRNA gene sequences indicated that strain WB 1.1-56T was phylogenetically most closely related to Flavobacterium frigidimaris KUC-1T, and that strain WB 4.2-33T was related most closely to F. frigidimaris KUC-1T and Flavobacterium saccharophilum DSM 1811T. Levels of 16S rRNA gene sequence similarity between strains WB 1.1-56T and WB 4.2-33T and the type strains of recognized members of the genus Flavobacterium were below 98 %. DNA-DNA hybridization experiments confirmed the separate genomic status of strains WB 1.1-56T and WB 4.2-33T. Strains WB 1.1-56T and WB 4.2-33T and their respective relatives differed from phylogenetically related Flavobacterium species based on several phenotypic characteristics. On the basis of their phenotypic and phylogenetic distinctiveness, the two groups of strains are considered to represent two novel species, for which the names Flavobacterium aquidurense sp. nov. (type strain WB 1.1-56T=DSM 18293T=CIP 109242T) and Flavobacterium hercynium sp. nov. (type strain WB 4.2-33T=DSM 18292T=CIP 109241T) are proposed.