Hymenobacter armeniacus sp. nov. and Hymenobacter montanus sp. nov., two radiation-resistant bacteria from soil

Two bacterial strains, designated BT189(T) and BT664(T), were isolated from soil sampled in the Republic of Korea. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strains BT189(T) and BT664(T) belonged to the genus Hymenobacter. family Hymenobacteraceae (order Cytophagales). The 16S rRNA genes of the two strains shared a sequence similarity of 93.7%. The closely related species of strain BT189(T) were Hymenobacter rubidus DG7B(T) (97.1% 16S rRNA similarity) and Hymenobacter terrae DG7A(T) (96.7%). The closest related species to strain BT664(T) were Hymenobacter sedentarius DG5B(T) (95.3%) and Hymenobacter terrenus MIMtkLc17(T) (95.2%). The genome sizes of strains BT189(T) and BT664(T) were 5285287 and 5475357 bp. respectively. The genomic DNA G+C contents of strains BT189(T) and BT664(T) were 63.2 and 59.3mol%, respectively. The main fatty acids of strain BT189(T) were iso-C-1(5:)0, anteiso-C-15(:0) and summed feature 3 (C-16:1 omega 6c/C-16:1 omega 7c), and those of strain BT664(T) were iso-C-15:0, C-16:1, omega 5c and summed feature 3 (C-16:1 omega 6c/C-16:1 omega 7c). The main polar lipid in both strains was phosphatidylethanolamine and the predominant respiratory quinone was MK-7, supporting the affiliation of these strains with the genus Hymenobacter. Based on the results of biochemical, chemotaxonomic and phylogenetic analyses, two novel species. Hymenobacter armeniacus BT189(T) (=KCTC 72341(T) =NBRC 114843(T)) and Hymenobacter montanus B1664(T) (KACC 21967(T) =NBRC 114856(T)), are proposed.