Cu^(2+)对酿酒酵母酒精发酵特性的影响

Effect of Cu^(2+) on Fermentation Characteristics of Saccharomyces cerevisiae

本文利用两株酿酒酵母Freddo(F菌)、BH8(B菌)和模拟葡萄汁发酵体系,研究了不同浓度Cu2+对酿酒酵母生长和发酵特性的影响。结果表明,Cu2+抑制发酵前期酵母生长、酒精发酵的程度和延长酒精发酵时间与Cu2+浓度正相关,当Cu2+浓度达到0.2 m M时,酵母酒精发酵出现提前终止。发酵结束时,B菌对照组葡萄糖和果糖的残留量为2.51 g/L、10.80 g/L,Cu2+0.1 m M处理组葡萄糖和果糖残留量分别为0.43 g/L、3.43 g/L,Cu2+0.1 m M处理促进了B菌发酵后期对糖的利用;F菌Cu2+处理组与对照组残糖量之间不存在显著性差异。B菌Cu2+0.1 m M处理组酒精总产量为10.80%,显著高于对照组的10.27%与Cu2+0.05 m M处理组的10.37%。B菌Cu2+0.05 m M处理组的甘油产量为6.66 g/L,显著高于对照组的6.37 g/L与Cu2+0.1 m M处理组的6.29 g/L;F菌Cu2+处理组与对照相比,酒精和甘油总产量之间不存在显著性差异,可见,不同株酵母对Cu2+逆境的适应性不同的。

The aim of this study was to understand the effect of Cu2＋ on the growth and fermentation characteristics of Saccharomyces cerevisiae. An industrial S. cerevisiae strain Freddo （F） and a new S. cerevisiae strain BH8 （B） isolated in our lab were used, and a simulated grape juice fermentation system was conducted. The results showed that Cu2＋ inhibited the early growth orS. cerevisiae, and the extent and time of alcoholic fermentation positively correlated with Cu2＋ concentration. When fermentation with 0.2 mM Cu2＋, the process terminated earlier. The Residual glucose and fi-uctose concentrations in the control （with no Cu2＋ ）for strain B were 2.51 g/L and 10.80 g/L, respectively. On the other hand, at 0.1 mM Cu2＋, these values were 0.43 g/L and 3.43 g/L, respectively, for Cu2＋-treated strain B. This indicated that 0. l mM Cu2＋ promoted sugar utilization in late fermentation by strain B. There was no significant difference in residual sugar concentration between control and Cu2＋-treated groups for strain F. The ethanol yield of 0.1 mM Cu2＋-treated strain B was 10.80%, which was significantly higher than that of the control （10.27%） and 0.05 mM Cu2＋-treated （10.37%） strain B groups. The glycerol yield of 0.05 mM Cu2＋-treated strain B was 6.66 g/L, which was significantly higher than that of the control （6.37 g/L） and 0.1 mM Cu2＋-treated （6.29 g/L） strain B groups. In comparison, Cu2＋-treated strain F and control groups showed no significant difference in ethanol and glycerol yield. Therefore, the adaptability of different yeast strains to Cu2＋ stress was different.