干旱区生态环境知识资源中心

Two gamma- and UV-radiation-resistant, pink-coloured bacterial strains, designated YIM F302(T) and YIM F235, were isolated from the desert of Yanbu’ al Bahr located in west of Saudi Arabia. Taxonomic positions of the two isolates were investigated by polyphasic taxonomic approaches. Cells of the two strains were Gram-stain-negative, aerobic and rod-shaped. They were able to grow at 15-45 degrees C and pH 6.0-8.0 and had a NaCl tolerance limit of 1% (w/v). Phylogenetic analyses based on 16S rRNA gene sequences revealed that strains YIM F302(T) and YIM F235 represent members of the genus Deinococcus, sharing highest sequence similarities of 98.3 and 98.4%, respectively, with Deinococcus grandis DSM 3963(T). The strains were found to contain MK-8 as the respiratory menaquinone. Major fatty acids (>10%) of the two strains were C-15:1 omega 6C, C-16:0 and C-16:1 omega 7C. DNA DNA hybridization values of the two isolates against the closely related type strains were significantly below the 70% limit for species delineation. Genomic DNA G+C contents of strains YIM F302(T) and YIM F235 were 69.3 and 69.0 mol%, respectively. Based on the phenotypic and genotypic characteristics recorded, it is determined that the two isolates represent a novel species of the genus Deinococcus, for which the name Deinococcus saudiensis sp. nov. is proposed. The type strain is YIM F302(T) (=CGMCC 1.15089(T)=DSM 29933(T)).