干旱区生态环境知识资源中心

Three Gram-stain-positive, catalase- and oxidase-positive coccus- or rod-shaped bacterial strains, designated BM2(T), BM4 and BM5, were isolated from soil in South Korea. They showed strong resistance to gamma radiation with a D-10 value of 9 kGy but weak UVC resistance. The 16S rRNA sequences of strains BM2(T), BM4 and BM5 represent a novel subline within the genus Deinococcus in the family Deinococcaceae. The 16S rRNA gene sequences of strains BM2(T), BM4 and BM5 were indistinguishable and showed 98.1-87.3 % similarity with other species of the genus Deinococcus. Strain BM2(T) exhibited relatively high levels of DNA-DNA hybridization with BM4 (87 +/- 0.8 %) and BM5 (92 +/- 1.2 %). Meanwhile, it showed a low level of DNA-DNA hybridization (<30 %) with other closely related species of the genus Deinococcus. The strains showed the typical chemotaxonomic characteristics of the genus Deinococcus, with the presence of menaquinone 8 as the respiratory quinone; the major fatty acids were summed feature 3 (composed of C-16 : 1 omega 7c/C-16 : 1 omega 6c), C-15 : 1 omega 6c and C-16 : 0. The DNA G+C content of strain BM2(T) was 69.7 mol%. The polar lipid profile included major amounts of phosphatidylglycerol, phosphatidylcholine and an unknown aminolipid. On the basis of phenotypic and genotypic properties, and phylogenetic distinctiveness, strains BM2(T), BM4 and BM5 should be classified in a novel species in the genus Deinococcus, for which the name Deinococcus actinosclerus sp. nov. is proposed. The type strain is BM2(T) (=KEMB 5401-184(T)=JCM 30700(T)); reference strains are BM4 (=JCM 30701) and BM5 (=JCM 30702).