Long-term population dynamics of viable microbes in a closed ecosystem of fermented vegetables

This study was performed to investigate the succession of various microorganisms naturally present in raw ingredients and the changes in metabolites following long-term fermentation of kimchi. Kimchi was stored at 4 degrees C for 500 days, and the composition of the microbial community and the nature of metabolites were analyzed using metataxonomics and metabolomics. We confirmed that the taxa belonging to Leuconostoc and Weissella were dominant in the early stages of fermentation, while Latilactobacillus and Levilactobacillus were dominant in the middle and late fermentation stages, respectively. In the eukaryotic community, Cladosporium was dominant in the early stages, while Pichia and Hanseniaspora tended to increase in the middle and late fermentation stages. The longitudinal metabolite profile demonstrated that about half (55.7%) of the metabolites present in kimchi after 500 days of fermentation were produced within 15 days of fermentation due to rapid fermentation in the initial stage. These results revealed that even in a closed environment, the viable microbiota in fermented vegetables are not static but dynamic, and the composition of metabolites evolves accordingly during long-term fermentation.

Automated summary

This study investigated the succession of microorganisms and changes in metabolites during long-term fermentation of kimchi. The dominant taxa shifted from Leuconostoc and Weissella in the early stages to Latilactobacillus and Levilactobacillus in the middle and late stages. The metabolite analysis showed that about half of the metabolites were produced within the first 15 days of fermentation. These findings highlight the dynamic nature of microbiota and the evolving composition of metabolites during long-term fermentation.