Lactic acid bacterial communities in kimchi prepared by representative Korean kimchi companies were investigated using a pyrosequencing method. The pH values of 9 kimchi varieties (K1-K9) ranged from 4.3 to 4.7, and total lactic acid bacterial (LAB) counts ranged from 1.3x10 to 1.6x10 CFU/g. ,, and were the dominant genera accounting for 52, 28, and 20%, respectively, of identified genera. At the species level, (35%) dominated, followed by (13%), and (11%). Dominant LAB were all heterofermentative LAB. K1 had the most diverse operational taxonomic units (OTUs), and clustering analysis showed that distributions of microorganisms in K2, K6, K5, and K4 were similar each other. LAB communities in kimchi are diverse and heterofermentative LAB dominate in Korean commercial kimchi.

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Fermentation characteristics and health functionalities of kimchi by inoculating kimchi lactic acid bacteria (LAB) starters were studied. We isolated two kinds of LAB (Lab. plantarum pnu and Leu. mesenteroides pnu), and manufactured single LAB starter kimchis (Lab. plantarum pnuK, Lab. plantarum 3099K, Leu. mesenteroides pnuK), mixed LAB starter kimchis (Lab. plantarum pnu/Leu. mesenteroides pnuK, Lab. plantarum 3099/Leu. mesenteroides pnuK) with inoculum size of 106 CFU/g and naturally fermented kimchi (NK) as a control. These kimchis were fermented for 6 days at 15℃. Kimchi with the starters rapidly decreased in pH and increased in acidity. During fermentation, kimchis with or without Lab. plantarum (LP) showed similar levels of total aerobic bacteria and Lactobacillus sp., but kimchis with the Leuconostoc sp. showed higher levels of Leuconostoc sp. than the kimchis without the inoculation. LAB inoculated kimchis showed higher antioxidative effects than NK. In the MTT assay of HCT‐116 and HT‐29 human colon cancer cells, LPpnuK exhibited the highest inhibition rates (77.1 and 68.8%). In mRNA expressions of the LAB inoculated kimchis, Bax, p53 and p21 were increased, and Bcl‐2, iNOS and COX‐2 were decreased. Therefore, inoculating of LAB starters can promote health beneficial effects of kimchi.