Sejongia antarctica gen. nov., sp nov. and Sejongia jeonii sp. nov., isolated from the Antarctic

Two yellow-pigmented, Gram-negative and aerobic bacterial strains, designated AT1013^T and AT1047^T, were isolated from terrestrial samples of the Antarctic. On the basis of 16S rRNA gene sequence analyses, the two Antarctic strains shared 97.7% sequence similarity and showed moderate relationships to the genera Chryseobacterium (92.5-95.3%), Riemerella (92.3-93.5%), Bergeyella (92.5-92.6%) and Kaistella (92.5-93.3%). In phylogenetic analyses, the two isolates formed a robust monophyletic clade and represented a distinct phyletic line that equated to novel generic status. Cells were non-motile, non-gliding and psychrotolerant with an optimum growth temperature of about 20 °C. Flexirubins were absent. The major isoprenoid quinone was MK-6. The predominant cellular fatty acids were 15:0 iso, 15:0 anteiso and 17:1 iso ω9c. DNA G+C contents were 34-36 mol%. The two isolates shared low genomic relatedness (27%) and were differentiated from each other by several phenotypic characteristics. The polyphasic data presented in this study indicated that these isolates should be recognized as two separate novel species in a novel genus within the family Flavobacteriaceae. The name Sejongia gen. nov. is therefore proposed for the Antarctic isolates, with the type species Sejongia antarctica sp. nov. (type strain AT1013^T=IMSNU 14040^T=KCTC 12225^T=JCM 12381^T) and Sejongia jeonii sp. nov. (type strain AT1047^T=IMSNU 14049^T=KCTC 12226^T=JCM 12382^T).