TCA循环中间产物对酿酒酵母胞内代谢关键酶活性的影响

对酿酒酵母在添加苹果酸、柠檬酸和琥珀酸的混合培养基与其在YEPD培养基中胞内丙酮酸激酶、葡萄糖-6-磷酸脱氢酶、异柠檬酸脱氢酶、苹果酸脱氢酶、乙醇脱氢酶的酶活力差异进行了对比分析。结果表明:添加苹果酸使胞内丙酮酸激酶、异柠檬酸脱氢酶、苹果酸脱氢酶、乙醇脱氢酶的酶活分别下降34.82%、57.23%、39.15%、12.10%;添加柠檬酸使胞内丙酮酸激酶、异柠檬酸脱氢酶、苹果酸脱氢酶的酶活分别下降50.17%、42.20%、48.40%;添加琥珀酸使胞内丙酮酸激酶、葡萄糖-6-磷酸脱氢酶、异柠檬酸脱氢酶、苹果酸脱氢酶、乙醇脱氢酶的酶活分别下降34.16%、34.16%、50.87%、50.87%、12.37%。丙酮酸激酶、异柠檬酸脱氢酶和苹果酸脱氢酶对3种有机酸的耐受性较差,葡萄糖-6-磷酸脱氢酶、乙醇脱氢酶对3种有机酸的耐受具有选择性。

Effects of Adding Intermediate Material in Tricarboxylic Acid Cycle on the Activity of Key Enzymes of Saccharomyces cerevisiae

The enzyme activity of some key metabolic enzymes (pyruvate kinase, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, malate dehydrogenase and ethanol dehydrogenase) in Saccharomyces cerevisiae with YEPD medium were compared with malic aicd, citric acid and succinic acid mixed medium. The result showed that after adding malic acid, enzymatic activity of pyruvate kinase, isocitrate dehydrogenase, malate dehydrogenase and ethanol dehydrogenase respectively declined 34.82%, 57.23%, 39.15% and 12.10%; after adding citric acid, enzymatic activity of pyruvate kinase, isocitrate dehydrogenase and malate dehydrogenase respectively declined 50.17%, 42.20% and 48.40%; after adding succinic acid, enzymatic activity of pyruvate kinase, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, malate dehydrogenase and ethanol dehydrogenase respectively declined 34.16%, 34.16%, 50.87%, 50.87% and 12.37%. Pyruvate kinase, isocitrate dehydrogenase and malate dehydrogenase had bad tolerance to three kinds of organic acids, tolerance of glucose-6-phosphate dehydrogenase and ethanol dehydrogenase to three kinds of organic acids had selectivity.