Pontibacter pudoricolor sp. nov., and Pontibacter russatus sp. nov. radiation-resistant bacteria isolated from soil.

Gram-stain-negative, aerobic, non-flagellated, red-colored strains BT214 and BT326 were isolated from soil collected in Uijeongbu city, Korea. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strains BT214 and BT326 formed a distinct lineage within the family Hymenobacteraceae (order Chitinophagales, class Chitinophagia) and were most closely related to members of the genus Pontibacter, Pontibacter populi HLY7-15 (96.9% 16S rRNA gene sequence similarity) and Pontibacter amylolyticus 9-2 (96.1%), respectively. Optimal growth of two strains occurred at 25 °C, pH 7.0 and in the absence of NaCl. The predominant cellular fatty acids were summed feature 4 (iso-C I/anteiso-C B) and iso-C. The major respiratory quinone of two strains was MK-7. The major polar lipid of two strains was phosphatidylethanolamine. Biochemical, chemotaxonomic and phylogenetic analyses indicated that strains BT214 and BT326 represent novel bacterial species within the genus Pontibacter, for which the names Pontibacter pudoricolor and Pontibacter russatus are proposed. The type strains of Pontibacter pudoricolor and Pontibacter russatus are BT214 and BT326, respectively.