Oxidative stress of wine yeasts under copper exposure | 铜对葡萄酒酿酒酵母的氧化胁迫机制

Chinese. 【目的】研究铜离子对葡萄酒酿酒酵母的氧化胁迫作用,为葡萄酒酿造过程的铜离子控制提供依据。【方法】以模拟葡萄汁为酵母培养基,添加CuSO4分别设置0、0.05、0.10、0.20、0.50和1.00 mmol?L-1Cu2+浓度。另外设置0.50 mmol?L-1 H2O2的处理作为氧化胁迫的对比。【结果】铜胁迫下酿酒酵母细胞内超氧阴离子的产生速率和过氧化氢的含量增加。酿酒酵母膜脂过氧化程度加剧,细胞内丙二醛含量随着铜处理浓度的增加而增加。酿酒酵母细胞内超氧化物歧化酶和过氧化氢酶的活性在铜胁迫下有不同程度的升高。铜胁迫下谷胱甘肽和甘油在酿酒酵母细胞内大量积累。【结论】铜胁迫刺激酿酒酵母细胞内活性氧的形成,产生与过氧化氢类似的氧化胁迫,而且酵母细胞的抗氧化酶体系和非酶抗氧化系统可协同作用减少细胞受到的伤害。

English. 【Objective】 To provide a basis for the control of copper iron during winemaking, the oxidative stress of wine yeasts under copper exposure was studied. 【Method】 In the present experiment, the model synthetic medium (MSM) was used as yeast culture medium. CuSO4 was added into the medium at concentrations of 0,0.05,0.10,0.20,0.50 mmol?L-1 and 1.00 mmol?L-1 Cu2+, respectively, and 0.50 mmol?L-1 H2O2 treatment was set as the comparison of oxidative stress. 【Result】 Production rate of superoxide anion and hydrogen peroxide content increased in wine yeasts under copper stress. Copper stress also aggravated the cell lipid peroxidation, and intracellular malondialdehyde(MDA) increased with copper concentrations. Superoxide dismutase and catalase activities were enhanced to different levels under copper stress. It was also discovered that glutathione and glycerol both accumulated much in cells under copper stress. 【Conclusion】 Copper stress stimulated the production of reactive oxygen species and caused oxidative stress similar to treatment with H2O2. Antioxidant enzyme system of yeast cells and non-enzymatic antioxidant systems have synergistic effect on reducing the damage under high concentrations of copper.