Spirosoma aureum sp. nov., and Hymenobacter russus sp. nov., radiation-resistant bacteria in Cytophagales order isolated from soil

A Gram-stain-negative, aerobic, nonmotile, yellow-colored strain BT328 T and Gram-stain-negative, aerobic, non-motile, red-colored strain BT18 T were isolated from the soil collected in Korea. Phylogenetic analyses based on 16S rRNA gene sequence revealed that strain BT328 T formed a distinct lineage within the family Spirosomaceae (order Cytophagales , class Cytophagia ) and was most closely related to a member of the genus Spirosoma , Spirosoma terrae 15J9-4 T (95.9% 16S rRNA gene sequence similarity). Optimal growth occurred at 25 °C, pH 7.0 and in the absence of NaCl. The predominant cellular fatty acids were summed feature 3 (C 16:1 ω 6 c /C 16:1 ω 7 c ) and C 16:1 ω 5 c . The major respiratory quinone was MK-7. The major polar lipid was phosphatidylethanolamine. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain BT18 T formed a distinct lineage within the family Hymenobacteraceae (order Cytophagales , class Cytophagia , phylum Bacteroidetes ) and was most closely related to members of the genus Hymenobacter , Hymenobacter knuensis 16F7C-2 T (97.0% 16S rRNA gene sequence similarity). Optimal growth occurred at 25 °C and pH 7.0 without NaCl. The major fatty acids were iso-C 15:0 and anteiso-C 15:0 . The major menaquinone was MK-7. The major polar lipid was phosphatidylethanolamine. Biochemical, chemotaxonomic and phylogenetic analyses indicated that strains BT328 T and BT18 T represents a novel bacterial species within the genus Spirosoma and Hymenobacter , respectively. For which the name Spirosoma aureum and Hymenobacter russus is proposed. The type strain of S. aureum is BT328 T (=KCTC 72365 T = NBRC 114506 T ) and the type strain of H. russus is BT18 T (=KCTC 62610 T = NBRC 114380 T ).