Microbacterium radiodurans sp. nov., a UV radiation-resistant bacterium isolated from soil

Abstract

Strain GIMN 1.002(T), a UV radiation-tolerant bacterium, was isolated from the upper sand layers of the Gobi desert, Xinjiang, China and characterized in order to determine its taxonomic position. Cells were Gram-reaction-positive, heterotrophic, strictly aerobic, short rods. 16S rRNA gene sequence analysis revealed that strain GIMN 1.002(T) belonged to the genus Microbacterium and was closely related to Microbacterium arborescens DSM 20754(T) (98.8 % 16S rRNA gene sequence similarity) and Microbacterium imperiale DSM 20530(T) (98.7 %). However, strain GIMN 1.002(T) had low DNA-DNA relatedness with M. arborescens DSM 20754(T) (17.1 %) and M. imperiale DSM 20530(T) (12.89 %). Strain GIMN 1.002(T) possessed chemotaxonomic markers that were consistent with its classification in the genus Microbacterium, i.e. MK-11, MK-12 and MK-10 as major menaquinones and anteiso-C(15 : 0) (38.67 %), iso-C(16 : 0) (18.16 %) and iso-C(15 : 0) (17.46 %) as predominant cellular fatty acids. The DNA G+C content was 67.74 mol%. The cell-wall sugar was rhamnose. On the basis of the data from this study, strain GIMN 1.002(T) represents a novel species of the genus Microbacterium, for which the name Microbacterium radiodurans sp. nov. is proposed. The type strain is GIMN 1.002(T) (=CCTCC M208212(T) =NRRL B-24799(T)).