Mucilaginibacter roseus sp. nov., isolated from a freshwater river.

Abstract

A bacterial strain, designated TTM-1T, was isolated from a water sample taken from the Caohu River in Taiwan and characterized in a taxonomic study using a polyphasic approach. Cells of strain TTM-1T were Gram-stain-negative, aerobic, non-motile, rod-shaped and covered by large capsules, and formed pink-coloured colonies. Growth occurred at 10-37 °C (optimum 30-37 °C), at pH 6-8 (optimum pH 6-7) and with 0-2 % NaCl (optimum 0.5 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain TTM-1T belonged to the genus Mucilaginibacter and was most closely related to Mucilaginibacter defluvii A5T with a 16S rRNA gene sequence similarity of 97.3 %. The predominant fatty acids of strain TTM-1T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 37.1 %) and iso-C15 : 0 (30.7 %). The polar lipid profile consisted of phosphatidylethanolamine and several uncharacterized aminophospholipids and phospholipids. The major isoprenoid quinone was MK-7. The DNA G+C content of the genomic DNA was 45.1 mol%. The DNA-DNA relatedness of strain TTM-1T with respect to recognized species of the genus Mucilaginibacter was less than 70 %. On the basis of the phylogenetic inference and phenotypic data, strain TTM-1T represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter roseus sp. nov. is proposed. The type strain is TTM-1T ( = LMG 28454T = KCTC 42273T).