Deinococcus taeanensis sp. nov., a Radiation-Resistant Bacterium Isolated from a Coastal Dune

Abstract

A Gram-stain-negative, nonspore-forming, nonmotile, aerobic, rod-shaped, and very pale orange-colored bacterial strain, designated TS293T, was isolated from a sand sample obtained from a coastal dune after exposure to 3kGy of gamma (γ)-radiation. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the isolate was a member of the genus Deinococcus and clustered with D. deserti VCD115T. The genome of strain TS293T was 4.62 Mbp long (68.2% G + C content and 4124 predicted genes) divided into a 2.86Mb main chromosome and five plasmids. Many genes considered to be important to the γ-radiation and oxidative stress resistance of Deinococcus were conserved in TS293T, but genome features that could differentiate TS293T from D. deserti and D. radiodurans, the type species of the Deinococcus genus, were also detected. Strain TS293T showed resistance to γ-radiation with D10 values (i.e., the dose required to reduce the bacterial population by tenfold) of 3.1kGy. The predominant fatty acids of strain TS293T were summed feature 3 (C16:1ω6c and/or C16:1ω7c) and iso-C16:0. The major polar lipids were two unidentified phosphoglycolipids and one unidentified glycolipid. The main respiratory quinone was menaquinone-8. Based on the phylogenetic, genomic, physiological, and chemotaxonomic characteristics, strain TS293T represents a novel species, for which the name Deinococcus taeanensis sp. nov. is proposed. The type strain is TS293T (= KCTC 43191T = JCM 34027T).