Methylobacterium durans sp. nov., a radiation-resistant bacterium isolated from gamma ray-irradiated soil

Abstract

A gamma radiation-resistant, Gram-stain negative, oxidase and catalase positive, aerobic, flagellated, rod-shaped, methylotrophic and pink-pigmented bacterial strain designated 17SD2-17 (T) was isolated from gamma-ray-irradiated soil collected in Korea. The 16S rRNA gene sequence analysis showed that strain 17SD2-17 (T) is phylogenetically related to Methylobacterium organophilum DSM 760 (T) (97.6%), Methylobacterium oxalidis 35a(T) (97.4%) and Methylobacterium soli YIM 48816 (T) (97.0%). The G+C content calculated based on the draft genome sequence is 68.7 mol%. The DNA-DNA hybridisation between 17SD2-17 (T) and its close relatives was found to be less than 40%. The predominant fatty acid was identified as summed feature 8 (C-18:1 omega 7c and/or C-18:1 omega 6c) and the major respiratory quinone as Q-10. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. On the basis of the data from phenotypic tests and genotypic differences between strain 17SD2-17 (T) and its close phylogenetic relatives, strain 17SD2-17 (T) is concluded to represent a new species belonging to the genus Methylobacterium, for which the name Methylobacterium durans sp. nov. (= KCTC 52908 (T) = NBRC 112876 (T)) is proposed.