Sawada Kazunori, Yamada Takuji
Innovation Division, Gurunavi, Inc., Hibiya Mitsui Tower, Chiyoda-ku, Tokyo, Japan.
School of Life Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan.
Microbiol Spectr. 2024 Aug 6;12(8):e0046424. doi: 10.1128/spectrum.00464-24. Epub 2024 Jul 17.
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 Microbiota analysis indicated two successional patterns: early dominance of lactic acid bacteria superseded by aerobic bacteria and early dominance of lactic acid bacteria maintained to the end of the production process.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.
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.
本研究旨在调查初始微生物群对茄子发酵过程中微生物演替和代谢物转变的影响。使用由植物相关微生物群自发发酵的传统日本茄子泡菜样本进行分析。微生物群分析表明有两种演替模式：乳酸菌早期占主导地位，随后被需氧菌取代；以及乳酸菌早期占主导地位并维持到生产过程结束。接下来，使用经过过滤除菌的茄子汁进行模拟生产，按照初始微生物群的平均组成进行发酵，该初始微生物群是由在生产过程中鉴定出的六个主要物种人工构建而成。与实际生产不同，所有批次的茄子汁发酵都显示出几乎相同的微生物演替，并且在最终微生物群中完全由[具体微生物]占主导。这些发现揭示了实际生产条件下初始微生物群的命运：乳酸菌早期占主导地位并贯穿始终，最终[具体微生物]在微生物群中占主导。此外，实际生产与茄子汁发酵结果的比较表明，无论最终微生物群如何，[具体微生物]都参与茄子发酵过程中乳酸、丙氨酸和谷氨酸的产生。
本研究结果为自发泡菜发酵过程中的微生物演替以及植物乳杆菌在茄子泡菜生产中的作用提供了见解。此外，使用经过过滤除菌的蔬菜汁与人工微生物群来模拟自发发酵的新方法可应用于其他自发发酵产品。这种方法能够在不存在可能促进对蔬菜发酵过程中复杂微生物生态系统中微生物行为有更深入理解的来自原材料的植物相关细菌的情况下，评估特定初始微生物群的影响。
