Flavobacterium aciduliphilum sp. nov., isolated from freshwater, and emended description of the genus Flavobacterium.

A Gram-stain-negative, rod-shaped, non-motile and yellow-pigmented bacterial strain, designated strain JJ013(T), was isolated from an artificial lake in Jeollabuk-do, South Korea, and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain JJ013(T) indicated that the isolate belonged to the family Flavobacteriaceae and exhibited similarity levels of 96.6 % to the type strains of Flavobacterium cheonanense and Flavobacterium koreense and 96.5 % to the type strain of Flavobacterium chungnamense. Growth was observed at 20-30 °C and pH 5.0-7.0. The major cellular fatty acids of the novel strain were iso-C15 : 0 (27.5 %), iso-C15 : 1 G (17.8 %), iso-C17 : 0 3-OH (9.4 %) and iso-C15 : 0 3-OH (9.2 %). Flexirubin-type pigments were present. The DNA G+C content of strain JJ013(T) was 33.9 mol%, the major respiratory quinone was menaquinone-6 (MK-6) and the major polyamine was sym-homospermidine. The polar lipid profile of the strain JJ013(T) consisted of a phosphatidylethanolamine (PE), two unknown aminolipids (AL1-2), three unidentified lipid (L1-3) and an unknown glycolipid (GL). On the basis of the morphological and physiological properties and biochemical evidence presented, it is concluded that strain JJ013(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium aciduliphilum sp. nov. is proposed; the type strain is JJ013(T) ( = KACC 16594(T) = JCM 18211(T)). Since C15 : 0, which is known as a predominant fatty acid of the genus Flavobacterium was not detected in the novel strain and other reference strains, we propose an emended description of the genus Flavobacterium.