Rheinheimera riviphila sp. nov., isolated from a freshwater stream

摘要

Strain KYPC3(T), isolated from a freshwater stream in Taiwan, was characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain KYPC3(T) belonged to the genus Rheinheimera. Strain KYPC3(T) exhibited 16S rRNA gene sequence similarity values of 94.8-97.9% to the type strains of species of the genus Rheinheimera. Strain KYPC3(T) was most closely related to Rheinheimera chironomi K19414(T) with 16S rRNA gene sequence similarity of 97.9%. Cells of strain KYPC3(T) were Gram-stain negative, aerobic, motile by means of a single-polar flagellum, non-spore forming, coccoid or short rods surrounded by a thick capsule and forming off-white coloured colonies. Growth occurred at 15-30 degrees C (optimum, 20-25 degrees C), at pH 6-8 (optimum, pH 7) and with 0-0.5% NaCl (optimum, 0%). The major fatty acids (> 10%) of strain KYPC3(T) were C-12:0 3-OH, summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 6c) and C-16:0. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, an uncharacterized aminophospholipid, an uncharacterized phospholipid and an uncharacterized lipid. The major isoprenoid quinone was Q-8. The draft genome was approximately 4.75 Mb in size with a G + C content of 49.8 mol%. The DNA-DNA relatedness of strain KYPC3(T) with respect to recognized species of the genus Rheinheimera was significantly less than 70%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain KYPC3(T) should be classified as a novel species of the genus Rheinheimera, for which the name Rheinheimera riviphila sp. nov. is presented. The type strain is KYPC3(T) (= BCRC 81008(T) = LMG 29729(T) = KCTC 52440(T)).