Flavobacterium undicola sp. nov., isolated from a freshwater lake.

Bacterial strain BBQ-18, isolated from a freshwater lake in Taiwan, is characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicate that strain BBQ-18 forms a phylogenetic lineage in the genus Flavobacterium. Strain BBQ-18 is most closely related to Flavobacterium alvei HR-AY with 98.5% 16S rRNA gene sequence similarity. Strain BBQ-18 shows 70.5-89.5% average nucleotide identity and 13.7-38.2% digital DNA-DNA hybridization identity with the type strains of other closely related Flavobacterium species. The strain is Gram-stain negative, strictly aerobic, motile by gliding, rod shaped and formed yellow colonies. Optimal growth occurs at 25 °C, pH 6, and in the absence of NaCl. Strain BBQ-18 contains iso-C, summed feature 3 (Cω6c and/or Cω7c) and anteiso-C as the predominant fatty acids. The polar lipid profile consists of phosphatidylethanolamine, four uncharacterized aminophospholipids and two uncharacterized phospholipids. The major polyamine is homospermidine. The major isoprenoid quinone is MK-6. The DNA G+C content of the genomic DNA is 33.8%. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain BBQ-18 should be classified as a novel species of the genus Flavobacterium, for which the name Flavobacterium undicola sp. nov. is proposed. The type strain is BBQ-18 (= BCRC 81050 = LMG 30052 = KCTC 52810).