Flavobacterium buctense sp. nov., isolated from freshwater.

A gram-negative, non-gliding motile, aerobic bacterium, designated as strain T7(T), was isolated from freshwater of Chishui River flowing through Maotai town, Guizhou Province, southwest of China. Based on the 16S rRNA gene sequence analysis, the isolate was identified as a member of the genus Flavobacterium and that shared less than 97 % sequence similarities with recognized Flavobacterium species. Its closest phylogenetic relative was Flavobacterium dankookense (96.9 %), followed by Flavobacterium cheonhonense (96.8 %) and Flavobacterium macrobrachii (96.7 %). The strain formed smooth yellow colonies on R2A plates, and cells were observed to be short rods. Strain T7(T) was found to be able to grow at 15-30 °C (optimum 25 °C), at NaCl concentration of 0-0.5 % (optimum 0 %) and at pH 6.5-9.5 (optimum pH 7.5). Catalase and oxidase tests were positive. Polar lipids of strain T7(T) included phosphatidylethanolamine, four unidentified polar lipids, one unidentified phospholipid and one unidentified aminolipid. Chemotaxonomic analysis revealed menaquinone-6 as the dominant respiratory quinone and C(15:0), iso-C(15:0) and iso-C(15:1) as the major fatty acids. The DNA G+C content of strain T7(T) was determined to be 38.2 mol%. On the basis of phylogenetic, phenotypic and genetic data obtained in this study, strain T7(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium buctense sp. nov. is proposed. The type strain is T7(T) (=JCM 30750=CGMCC 1.15216).