Abstract

Three ionizing-radiation-resistant bacterial strains (designated KR-196, KR-198 and KR-200T) were isolated from a sample of arid soil collected from a coastal desert in Chile. The soil sample was irradiated before serial dilution plating was performed using one-tenth-strength plate count agar. Phylogenetic analysis of the 16S rRNA gene sequences showed these organisms to represent a novel species of the genus Deinococcus, having sequence similarities of 87.3-90.8 % with respect to recognized Deinococcus species. Strains KR-196, KR-198 and KR-200T were aerobic and showed optimum growth at 30 °C and pH 6.5-8.0. The major respiratory menaquinone was MK-8. The predominant fatty acids in these strains were 16:1ω7c, 16:0, 15:1ω6c, 17:0 and 18:0. The DNA G + C content of strain KR-200T was 63.9 mol%. Strains KR-196, KR-198 and KR-200T were found to be resistant to > 10 kGy gamma radiation. On the basis of the phylogenetic, chemotaxonomic and phenotypic data, strain KR-200T represents a novel species of the genus Deinococcus, for which the name Deinococcus peraridilitoris sp. nov. is proposed. The type strain is KR-200T (=LMG 22246T=CIP 109416T). © 2007 IUMS.