Effects of total microbiota-containing backslop from 450-day-fermented kimchi on microbe and metabolite dynamics

This study examines the impact of the complex microbiota from long-term fermented kimchi, used as a backslop, on fermentation dynamics. The fermentation was conducted with autoclaved (group A) and non-autoclaved (NA) starter cultures. Bacterial and fungal communities were analyzed with 16S rRNA gene V4 and ITS2 region, respectively, and metabolites were profiled using gas chromatography–mass spectrometry. In the group NA, Levilactobacillus dominated at 64.3 % by day 5, while Pediococcus reached 57.4 % by day 50. Principal coordinate analysis showed that bacterial communities in both the starter culture and samples of the group NA became similar by the end of the fermentation (day 100); however, no significant differences were found in fungal community. Principal component analysis revealed distinct metabolite profiles, explaining 68.7 % of variability on PC1, with each group clustered separately by day 100. These results suggest that inoculating with microbiota from long-term fermentation can rapidly produce foods with desirable characteristics. •Bacterial community in kimchi resembled that of starter culture after 100 days.•Pediococcus constituted 57.4 % of total ASVs on day 50 in non-autoclaved group.•Metabolite profiles formed distinctly separated clusters based on time points.