Flavobacterium alvei sp. nov., isolated from a freshwater river.

A yellow-pigmented, Gram-stain-negative, strictly aerobic, catalase-negative and oxidase-positive bacterium, designated strain HR-AYT, was isolated from a water sample of the Han River. Cells were non-motile rods without flagella. Growth was observed at 5-30 °C (optimum, 20 °C), pH 5-9 (optimum, pH 7) and 0 % NaCl. The major respiratory quinone was menaquinone-6. Strain HR-AYT did not produce flexirubin-type pigments. The major fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), anteiso-C15 : 0, iso-C15 : 0 and C16 : 0. The polar lipids comprised phosphatidylethanolamine and an unidentified phosphoamino lipid as major polar lipids, and four unidentified lipids were also detected as minor lipids. The DNA G+C content of strain HR-AYT was 34.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HR-AYT belonged to the family Flavobacteriaceae in the phylum Bacteroidetes, and formed a phylogenic lineage with members of the genus Flavobacterium. The 16S rRNA gene sequence similarity showed that strain HR-AYT was most closely related to Flavobacterium chungbukense CS100T (97.91 %) and Flavobacterium glaciei 0499T (97.74 %). Based on these results, strain HR-AYT represents a novel species of the genus Flavobacterium, for which the name Flavobacterium alvei sp. nov. is proposed. The type strain is HR-AYT (=KACC 19407T=JCM 32264T).