Abstract:

【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.

Key words: copper, wine yeast, oxidative stress, hydrogen peroxide