Three Novel Bacterial Species, Roseateles flavus sp. nov., Roseateles paludis sp. nov., and Roseateles hydrophilus sp. nov., Isolated from Various Water-Related Environments

Abstract

A polyphasic study was conducted to determine the taxonomic positions of three bacterial strains, designated as strains 2.12( T), DJS-2-20( T), and UHG3(T), isolated from the water of an agricultural water pipe, wetland, and artificial lake, respectively. These strains were Gram-stain-negative, rod-shaped, and oxidase positive. The fatty acid profiles of all three strains revealed that the major fatty acids (> 10%) were C-16:0 and summed features 3 (comprising C-16:1 omega 6c and/or C-16:1 omega 7c), with strain UHG3(T) additionally featuring C-16:0 3-OH as its main fatty acid. Phosphatidylethanolamine was the major polar lipid. Ubiquinone 8 (Q-8) was the only respiratory quinone detected. The genomic G + C contents were 68.5% for strain 2.12( T), 68% for strain DJS-2-20( T), and 69% for strain UHG3(T). Strains 2.12( T), DJS-2-20( T), and UHG3(T) had the closest 16S rRNA gene sequence similarity with R. subflavus APW6(T) (98.5%), R. puraquae CCUG 52769( T) (98.2%), and R. puraquae CCUG 52769( T) (99.4%), respectively. The pairwise amino acid identity, average nucleotide identity, and digital DNA-DNA hybridization values for strains 2.12( T), DJS-2-20( T), and UHG3(T) with its closely related type strain of the species were below the species delineation thresholds. The genotypic and phenotypic characteristics observed in this study indicated that strains 2.12( T) (= KACC 23730( T) = TBRC 19013( T)), DJS-2-20( T) (= KACC 23731( T) = TBRC 19014( T)), and UHG3(T) (= KACC 22636( T) = TBRC 16347( T)) represent three novel Roseateles species, for which we propose the names Roseateles flavus sp. nov., Roseateles paludis sp. nov., and Roseateles hydrophilus sp. nov., respectively.