Lactococcus kimchii sp. nov., a new lactic acid bacterium isolated from kimchi

A coccus strain designated S-13(T) was isolated from commercial baechu-kimchi in Korea. Comparison of the 16S rRNA gene sequence indicated that strain S-13(T) had the highest similarity to Lactococcus taiwanensis 0905C15(T) (97.9%), Lactococcus lactis subsp. tructae L105(T) (97.6%), Lactococcus lactis subsp. cremoris NCDO 607(T) (97.5%), Lactococcus lactis subsp. hordniae NBRC 100931(T) (97.2 %), and Lactococcus lactis subsp. lactis JCM 5805(T) (97.2%). The detailed phylogenetic analyses based on the 16S rRNA, rpoB and recA genes indicated that S-13(T) was separated from the other species and subspecies in the genus Lactococcus. The DNA-DNA relatedness between S-13(T) and closely related type strains, such as L. taiwanensis 0905C15(T), L. lactis subsp. tructae L105(T), L. lactis subsp. cremoris NCDO 607(T), L. lactis subsp. hordniae NBRC 100931(T), and L. lactis subsp. lactis JCM 5805(T) was 25.6, 20.4, 25.1, 20.2 and 21.7 %, respectively. The major fatty acids were C-16:0, cyclo-C-19:0 omega 8c and C-14:0. The DNA G+C content of S-13(T) was 39.4 mol%. From the results of the phenotypic characteristics and chemotaxonomic analysis, it was concluded that strain S-13(T) represents a novel species in the genus Lactococcus for which the name Lactococcus kimchii sp. nov. (=KCTC 21096(T)=NBRC 113348(T)) is proposed.