该研究通过测定抑菌圈直径、最低抑菌浓度（minimum inhibitory concentration，MIC）和最低杀菌浓度（minimum bactericidal concentration，MBC），评价茶皂素对酿酒酵母、鲁氏接合酵母及白色假丝酵母三种食源性腐败酵母的抑菌能力，并筛选出机理研究指示菌；进而通过考察时间-杀菌曲线、生物膜抑制率、菌体细胞形态、细胞膜通透性、细胞膜完整性、遗传物质以及蛋白泄露和胞内总蛋白等指标，阐述茶皂素抑菌机理。抑菌能力试验结果显示茶皂素对三种腐败酵母均有抑菌作用，其中酿酒酵母抑菌直径为16.00 mm，MIC和MBC分别为0.05、0.10 mg/mL，抑菌效果最为显著。以酿酒酵母为指示菌的抑菌机理研究结果表明：茶皂素可使菌体直接进入衰竭期；可显著抑制生物膜形成；可致菌体细胞发生不可逆转的塌陷扭曲；能破坏细胞膜完整性，增大细胞膜通透性，使胞内核酸和蛋白质大量泄露，还可干扰DNA正常合成，阻滞蛋白质合成表达。因此，茶皂素有望成为食品加工中针对食源性腐败酵母的一种天然食品防腐剂，该研究也可为拓展天然防腐剂在高渗食品中的应用提供理论依据。

In this paper, the bacteriostatic ability of tea saponin against three foodborn spoilage yeasts, Saccharomyces cerevisiae, Zygosaccharomyces routeri and Candida albicans, was evaluated by measuring the inhibitionzone, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Furthemore, the antibacterial mechanism was explored by using the time sterilization curve, biofilm inhibition rate, cell morphology, cell membrane permeability, cell membrane integrity, genetic material, protein leakage and total intracellular protein. The results of bacteriostatic ability test showed that tea saponin had bacteriostatic effect on three kinds of foodborne spoilage yeast. The inhibition zone of tea saponin on S. cerevisiae which had the most significant bacteriostatic effect was 16.00 mm, MIC and MBC were 0.05 mg/mL and 0.10 mg/mL respectively. The bacteriostatic mechanism of S. cerevisiae as indicator bacteria indicated that tea saponin could make the bacteria directly enter the depletion period, significantly inhibit the formation of biofilm and cause irreversible collapse and distortion of bacterial cells. Furthemore, it can not only destroy the integrity of cell membrane, increase the permeability of cell membrane, and leak a large number of intracellular nucleic acids and proteins, but also interfere with the normal synthesis of DNA and block the synthesis and expression of proteins. Therefore, tea saponin is expected to become a natural food preservative for foodborne spoilage yeast in food processing, and this study can also provide a theoretical basis for expanding the application of natural preservative in hypertonic food.

广东省本土创新创业团队项目（2019BT02N112）；广东省现代农业产业技术体系创新团队建设专项资金（2020KJ117）；广东省农业科学院农业优势产业学科团队建设项目（202108TD）