Effect of trehalose in resistance of wine yeast to copper stress | 海藻糖在酿酒酵母抗铜胁迫中的作用

Chinese. 目的研究铜胁迫下，酿酒酵母胞内海藻糖的积累情况及海藻糖对酿酒酵母的保护作用，为探讨铜胁迫下酿酒酵母的防御保护机制提供理论依据。方法以改良模拟葡萄汁为发酵培养基，分别对菌株AWRI、BH8和Freddo进行直接铜胁迫处理（Cu2+浓度为1.00 mmol#8226;L-1）、热激预处理（37oC，1 h）、再铜胁迫处理，同时，设定无铜培养为对照。测定各种处理下酿酒酵母的存活率、胞内海藻糖的积累和6-磷酸海藻糖合成酶（TPS1）酶活性的变化。结果与对照相比，1.00 mmol#8226;L-1Cu2+胁迫处理使酵母细胞内海藻糖的含量增加，TPS1酶活性提高。热激预处理可诱导海藻糖的积累，且铜胁迫下细胞的存活率也显著高于直接铜胁迫处理。相同处理条件下，菌株Freddo胞内海藻糖的含量最多，细胞存活率也最高。结论铜胁迫处理可诱导胞内海藻糖的积累，并且这一积累对铜胁迫下的酿酒酵母起到一定的保护作用。

English. Objective The accumulation circumstances of trehalose in wine yeast under copper stress and the protection for trehalose to wine yeast were studied in order to provide a theoretical basis for the research on defense mechanism of wine yeast under copper stress. Method In the present experiment, the modified model synthetic medium (MMSM) was used as yeast culture medium. Two treatment methods, direct-copper stress treatment (1.00 mmol#8226;L-1 Cu2+) and heat shock pre-treatment (37℃, 1 h) with subsequent copper stress treatment were used to treat the S. cerevisia AWRI, S. cerevisia BH8 and S. cerevisia Freddo, respectively. Non-Cu2+ treatment was used as control. The tests determine the survival percentage of wine yeast in different treatment, the accumulation of trehalose and the enzyme activity of trehalose-6-phosphate synthase (TPS1). Result Compared with the control, 1.00 mmol#8226;L-1 Cu2+ stress treatment increased the contents of trehalose and enhanced the TPS1 enzyme activity. Heat pre-treatment induced the accumulation of trehalose and improved the wine yeast survival percentage significantly more than direct-copper stress treatment. Among the three strains in the same treatment, S. cerevisia Freddo had the most abundant trehalose and highest wine yeast survival percentage. Conclusion Copper stress treatment could induce the accumulation of trehalose in wine yeast, which consequently serves as a protection for wine yeast under copper stress.