Flavobacterium fluminis sp. nov. to accommodate an aerobic, halotolerant and gliding flavobacterium isolated from freshwater

A Gram-stain-negative, aerobic, oxidase-positive, catalase-positive and rod-shaped bacterium designated strain 3R17T was isolated from freshwater. Strain 3R17T produced bright-yellow, circular, convex and smooth colonies on R2A agar, tryptic soy agar, potato dextrose agar, nutrient agar and brain-heart infusion agar media. The strain was motile by gliding. The strain grew at 4-30 °C (optimum, 25 °C), at pH 6-9 (optimum, pH 7) and in the presence of up to 3 % NaCl (optimum, 0 %) on R2A agar. The 16S rRNA gene sequence analysis indicated that 3R17T represents a member of the genus Flavobacterium and is most closely related to Flavobacterium resistens BD-b365T, with a sequence similarity of 97.78 %, but the strain formed a distinct phylogenetic lineage of its own. Fatty acid analysis indicated that a summed feature comprising C16 : 1ω7c and/or C16 : 1ω6c, iso-C15 : 0, iso-C15 : 1G, anteiso-C15 : 0, C16 : 0, iso-C17 : 0 3-OH and iso-C15 : 0 3-OH were the major components (>5 %). Strain 3R17T contained phosphatidylethanolamine (PE) and several unidentified aminolipids as main polar lipids, and MK-6 as the predominant isoprenoid quinone. Flexirubin pigments were not produced. The DNA G+C content was 35.4 mol%. The combination of physiological and chemotaxonomic properties distinguished 3R17T from related species of the genus Flavobacterium. On the basis of polyphasic taxonomy, 3R17T evidently represents a novel species within the genus Flavobacterium, for which the name Flavobacterium fluminis sp. nov. is proposed. The type strain is 3R17T (=KCTC 42062T=JCM 30338T).