A Gram-staining-positive, strictly aerobic, spherical, non-motile, red-pigmented bacterium, designated strain MK03T , was isolated from a soil sample collected in South Korea. The taxonomic position of the novel strain was investigated using a polyphasic approach. In phylogenetic analyses based on 16S rRNA gene sequences, strain MK03 T was placed in a clade formed by members of the genus Deinococcus in the family Deinococcaceae and appeared to be most closely related to Deinococcus aerolatus 5516T-9 T (97.4 % sequence similarity), and Deinococcus saxicola AA-1444 T (96.9 %). The genomic DNA G+C content of the novel strain was 64.5 mol%. The chemotaxonomic characteristics of strain MK03 T were typical of members of the genus Deinococcus: MK-8 was identified as the predominant respiratory quinine, the major fatty acids were C 16 : 1 v7c, C 15 : 1 v6c, C 16 : 0 and C 15 : 0, ornithine was found to be the diamino acid in the cell-wall peptidoglycan and 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 9 kGy. In hybridization experiments, only low DNA-DNA relatedness values (11.6-34.5 %) were recorded between the novel strain and its closest relatives in the genus Deinococcus. Based on the phylogenetic, chemotaxonomic, phenotypic and DNA-DNA relatedness data, strain MK03 T represents a novel species of the genus Deinococcus, for which the name Deinococcus humi sp. nov. is proposed. The type strain is MK03 T (5KCTC 13619At the time of writing, the genus Deinococcus, which was first established by Brooks & Murray (1981), contained 49 species. The current members of the genus Deinococcus are aerobic, generally Gram-staining-positive (some strains are Gram-staining-negative) and have L-ornithine in their cellwall peptidoglycan but no detectable teichoic acids. As some members of the genus Deinococcus also show remarkable resistance to radiation, they may prove useful as sources of radiation-resistant enzymes and other biomolecules (Kwon & Seo, 2010;Seong et al., 2010) and for cleaning up waste sites that contain radioactive contaminants as well as other hazardous materials (Servinsky & Julin, 2007;Cox & Battista, 2005).In the course of isolating micro-organisms from soil samples collected on the campus of Seoul Women's University, a Gram-staining-positive, non-motile, aerobic, non-spore-forming bacterium, designated strain MK03 T , was isolated. The results of preliminary 16S rRNA gene sequence analysis indicated that strain MK03T should be placed in the genus Deinococcus. The exact taxonomic position of the novel strain was subsequently determined using a polyphasic approach.
Strain MK03T was originally isolated from soil collected from a mountain within the campus of Seoul Women's University in Seoul, South Korea. A subsample (1 g) was immersed in 50 ml saline [0.85 % (w/v) NaCl] and vortexed. The resultant suspension was serially diluted and 100 ml of each dilution was spread on a plate of 10-fold-diluted R2A aga...