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

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_16:1ω6c and/or C_16:1ω7c), 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.