Comparative Effects of Leuconostoc lactis and Leuconostoc mesenteroides Starters on Kimchi Fermentation Dynamics and Metabolite Profiles.

This study evaluated the effects of two Leuconostoc starter-Leuconostoc (Leu.) lactis DMLL10 and Leu. mesenteroides KACC 12312T-on kimchi fermentation characteristics, microbial dynamics, and metabolite production. Kimchi samples were fermented at 4°C for 20 days, and changes in pH, titratable acidity, viable cell counts, organic acids, amino acids, and volatile compounds were analyzed using GC-MS, HPLC, and multivariate statistical methods. Both starters successfully initiated fermentation, but clear differences in metabolic patterns were observed. Leu. lactis DMLL10-inoculated kimchi showed a lower relative abundance of Latilactobacillus sakei, a homofermentative LAB associated with excessive acidification, than the control. Compared with Leu. mesenteroides, Leu. lactis DMLL10-inoculated kimchi showed a relatively lower final titratable acidity and generated a broader range of organic acids, amino acids, and volatile compounds. In particular, it produced higher levels of glutamic acid, contributing to umami taste, as well as unique volatiles such as octanoic acid and specific aldehydes, enhancing flavor complexity. In contrast, Leu. mesenteroides KACC 12312T showed faster acidification and a comparatively narrower metabolite profile. Multivariate and correlation analyses (PCA, OPLS-DA, and network mapping) revealed distinct fermentation patterns between the two tested starter strains. These findings support Leu. lactis DMLL10 as a promising alternative starter candidate for diversifying kimchi fermentation profiles, although further studies using multiple strains are required to determine whether the observed differences are species-specific or strain-dependent differences.