金属离子对低糖酵母发酵活性的影响

该研究考察了3种金属离子对低糖酵母发酵活力的影响。首先，采用响应面设计法对酵母发酵培养基进行了优化。通过Plackett-Burman设计试验筛选出3个主要因素：镁离子（Mg2+）、锌离子（Zn2+）、锰离子（Mn2+）。在这个基础上应用最陡爬坡路径法逼近最大响应值区域，然后利用响应面分析法确定最佳培养基配方为酵母抽提物（FM888） 10 g/L、蛋白胨（FM318） 20 g/L、葡萄糖20 g/L、六水合氯化镁 6.95 g/L、氯化锌1.78 mg/L、一水合硫酸锰0.069 mg/L。其次，将优化培养基配方应用于低糖酵母发酵，干酵母活力可达426.86 mL/g。经过3次平行试验的验证，实际的平均发酵活力与预测的发酵活力值相近，比优化前提高了24.8%。此研究对低糖酵母的工业化生产具有一定的指导意义。

Effects of metal ions on fermentation activity of low-sugar yeast

The effects of three kinds of metal ions on the fermentation activity of low-sugar yeast were researched. The medium of yeast fermentation was optimized by response surface methodology (RSM). The three main factors (including Mg2+, Zn2+, Mn2+) were screened by Plackett-Burman experiments. Then the path of the steepest ascent was applied to approach the optimal region of the three significant factors. The optimum medium formula was determined by RSM as followed: yeast extract (FM888) 10 g/L, peptone (FM318) 20 g/L, glucose 20 g/L, MgCl2·6H2O 6.95 g/L, ZnCl2 1.78 mg/L, MnSO4·H2O 0.069 mg/L. The optimum medium was applied in the low-sugar yeast fermentation and the dry yeast activity was up to 426.86 ml/g. After three parallel validation tests, the actual average fermentation activity was similar to the predicted fermentation activity, which was 24.8% higher than that of before optimization. The research would have certain guiding significance for the industrial production of the low-sugar yeast.