A bacterial strain, designated 17Sr1-1T, was isolated from gamma ray-irradiated soil. Cells of this strain were Gram-stain-negative, strictly aerobic, motile and non-spore-forming rods. Growth occurred at 18-42 ˚C and pH 6.0-8.0, but no growth occurred at 2 % NaCl concentration. The major fatty acids of strain 17Sr1-1T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), iso-C17 : 1ω5c and C16 : 0. The polar lipid profile contained diphosphatidylglycerol, glycolipid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and four unidentified lipids. The G+C content of the genomic DNA of 17Sr1-1T was 71.9 mol%. The 16S rRNA gene sequence analysis showed that strain 17Sr1-1T was phylogenetically related to Roseomonas pecuniae N75T and Roseomonas rosea 173-96T (96.6 and 96.3 % sequence similarity, respectively). The genotypic and phenotypic data showed that strain 17Sr1-1T could be distinguished from its phylogenetically related species, and that this strain represented a novel species within the genus Roseomonas, for which the name Roseomonas radiodurans sp. nov. (type strain 17Sr1-1T=KCTC 52899T=NBRC 112872T) is proposed as the first reported gamma ray-resistant Roseomonas species.
Keywords: Roseomonas; gamma ray resistance; novel species; polyphasic study.