Abstract

Tentative identification of Leuconostoc lactis IH23 isolated from kimchi (a fermented vegetable product) has been described previously with 16S rDNA sequencing (Choi, I., M. Sc. Thesis Inha Univ. 1999). This strain produced the slime identified as dextran based on IR, 13C- and 1H-NMR spectroscopic results. Further study proved that the isolate IH23 belongs to a homogeneous genetic group with L. lactis DSM 20202T and L. argentinum DSM 8581T. The results showed DNA-DNA homology of 99-100%, 16S rDNA gene sequence similarity (99.7%), and a phylogenetic relationship although L. argentinum DSM 8581T had lower homology (80-91%). These data indicate that L. argentinum DSM 8581T and the isolate IH23 belong to an identical species with L. lactis DSM 20202T at the genetic level, although in carbohydrate fermentation, the isolate IH23 was most closely related to L. argentinum DSM 8581T and quite different from L. lactis DSM 20202T. Here we first report the isolation of consistent phenotypic variation in Leuconostoc lactis. We also emphasize that the nomenclature of subspecies needs to be differentiated into the three strains mentioned above in Leuconostoc lactis.

• Keywords: kimchi; lactic acid bacteria; Leuconostoc lactis; dextran