College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China.
College of Food Science and Technology, Southwest Minzu University, Chengdu 610041, China.
J Agric Food Chem. 2023 Aug 23;71(33):12538-12548. doi: 10.1021/acs.jafc.3c03793. Epub 2023 Aug 14.
High concentrations of ethanol could cause intracellular oxidative stress in yeast, which can lead to ethanol-oxidation cross-stress. Antioxidant dipeptides are effective in maintaining cell viability and stress tolerance under ethanol-oxidation cross-stress. In this study, we sought to elucidate how antioxidant dipeptides affect the yeast cell wall and membrane defense systems to enhance stress tolerance. Results showed that antioxidant dipeptide supplementation reduced cell leakage of nucleic acids and proteins by changing cell wall components under ethanol-oxidation cross-stress. Antioxidant dipeptides positively modulated the cell wall integrity pathway and up-regulated the expression of key genes. Antioxidant dipeptides also improved the cell membrane integrity by increasing the proportion of unsaturated fatty acids and regulating the expression of key fatty acid synthesis genes. Moreover, the addition of antioxidant dipeptides significantly ( < 0.05) increased the content of ergosterol. Ala-His (AH) supplementation caused the highest content of ergosterol, with an increase of 23.68 ± 0.01% compared to the control, followed by Phe-Cys (FC) and Thr-Tyr (TY). These results revealed that the improvement of the cell wall and membrane functions of antioxidant dipeptides was responsible for enhancing the ethanol-oxidation cross-stress tolerance of yeast.
高浓度的乙醇会导致酵母细胞内氧化应激，从而导致乙醇氧化交叉胁迫。抗氧化二肽在维持细胞活力和应对乙醇氧化交叉胁迫方面非常有效。在这项研究中，我们试图阐明抗氧化二肽如何影响酵母细胞壁和膜防御系统，以增强其应激耐受性。结果表明，抗氧化二肽通过改变细胞壁成分，在乙醇氧化交叉胁迫下减少了细胞内核酸和蛋白质的渗漏。抗氧化二肽正向调节细胞壁完整性途径，并上调关键基因的表达。抗氧化二肽还通过增加不饱和脂肪酸的比例和调节关键脂肪酸合成基因的表达来改善细胞膜的完整性。此外，添加抗氧化二肽可显著（<0.05）增加麦角固醇的含量。与对照组相比，Ala-His（AH）的添加使麦角固醇的含量最高，增加了 23.68±0.01%，其次是 Phe-Cys（FC）和 Thr-Tyr（TY）。这些结果表明，抗氧化二肽对细胞壁和膜功能的改善有助于增强酵母对乙醇氧化交叉胁迫的耐受性。
