Influence of the initial microbiota on eggplant pickle and eggplant juice fermentation.

UNLABELLED

The present study aimed to investigate the effects of the initial microbiota on microbial succession and metabolite transition during eggplant fermentation. Samples of traditional Japanese eggplant pickles, , which were spontaneously fermented by plant-associated microbiota, were used for the analysis. Microbiota analysis indicated two successional patterns: early dominance of lactic acid bacteria superseded by aerobic bacteria and early dominance of lactic acid bacteria maintained to the end of the production process. Next, production was modeled using filter-sterilized eggplant juice, fermenting the average composition of the initial microbiota, which was artificially constructed from six major species identified during production. In contrast to production, all batches of eggplant juice fermentation showed almost identical microbial succession and complete dominance of in the final microbiota. These findings revealed the fate of initial microbiota under production conditions: the early dominance of lactic acid bacteria that was maintained throughout, with ultimately predominating the microbiota. Furthermore, a comparison of the results between production and eggplant juice fermentation suggested that is involved in the production of lactic acid, alanine, and glutamic acid during eggplant fermentation regardless of the final microbiota.

IMPORTANCE

The findings shown in this study provide insight into the microbial succession during spontaneous pickle fermentation and the role of plantarum in eggplant pickle production. Moreover, the novel method of using filter-sterilized vegetable juice with an artificial microbiota to emulate spontaneous fermentation can be applied to other spontaneously fermented products. This approach allows for the evaluation of the effect of specific initial microbiota in the absence of plant-associated bacteria from raw materials potentially promoting a greater understanding of microbial behavior in complex microbial ecosystems during vegetable fermentation.