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

Abstract

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 degreesC. Flexirubins were absent. The major isoprenoid quinone was MK-6. The predominant cellular fatty acids WE, re 15:0 iso, 15:0 anteiso and 17:1 iso omega9c. 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 T 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)).