Deinococcus swuensis sp nov., a gamma-radiation-resistant bacterium isolated from soil

Strain DY59(T), a Gram-positive non-motile bacterium, was isolated from soil in South Korea, and was characterized to determine its taxonomic position. Phylogenetic analysis based on the 16S rRNA gene sequence of strain DY59(T) revealed that the strain DY59(T) belonged to the family Deinococcaceae in the class Deinococci. The highest degree of sequence similarities of strain DY59(T) were found with Deinococcus radiopugnans KACC 11999(T) (99.0%), Deinococcus marmoris KACC 12218(T) (97.9%), Deinococcus saxicola KACC 12240(T) (97.0%), Deinococcus aerolatus KACC 12745(T) (96.2%), and Deinococcus frigens KACC 12220(T) (96.1%). Chemotaxonomic data revealed that the predominant fatty acids were iso-C-15:0 (19.0%), C-16:1 omega 7c (17.7%), C-15:1 omega 6c (12.6%), iso-C-17:0 (10.3%), and iso-C-17:1 omega 9c (10.3%). A complex polar lipid profile consisted of a major unknown phosphoglycolipid. The predominant respiratory quinone is MK-8. The cell wall peptidoglycan contained D-alanine, L-glutamic acid, glycine, and L-ornithine (di-amino acid). The novel strain showed resistance to gamma radiation, with a D-10 value (i.e. the dose required to reduce the bacterial population by 10-fold) in excess of 5 kGy. Based on the phylogenetic, chemotaxonomic, and phenotypic data, strain DY59(T) (=KCTC 33033(T) =JCM 18581(T)) should be classified as a type strain of a novel species, for which the name Deinococcus swuensis sp. nov. is proposed.