Kineococcus radiotolerans sp nov., a radiation-resistant, Gram-positive bacterium

A Gram-type positive, motile, coccus-shaped organism was isolated from a radioactive work area. Strain SRS30216(T) is an orange-pigmented bacterium that is catalase-positive, oxidase-negative and urease-negative. The orange pigment is most likely a carotenoid with absorption peaks at approximately 444, 471 and 501 nm. Cells normally grew in clusters, but individual, motile, flagellated cells were also observed. Growth of strain SRS30216(T) occurred at temperatures between 11 and 41 degreesC, between pH 5 and 9 and at NaCl concentrations up to and including 5%. Fatty acid composition was limited, with >90% of the fatty acids being anteiso 15:0. Alkenes of 19-24 carbons in length were detected during examination of the neutral lipids. Strain SRS30216(T) demonstrated high levels of resistance to gamma-radiation and desiccation. The most closely related recognized species is Kineococcus aurantiacus RA 333(T), which is 93% similar in 16S rDNA sequence. DNA-DNA hybridization revealed only 31 % similarity between these two organisms. It is proposed that SRS30216(T) (= ATCC BAA-149(T) = DSM 14245(T)) represents the type strain of a novel species in the genus Kineococcus, Kineococcus radiotolerans sp. nov.