保加利亚乳杆菌产酸关键酶的研究

Study on key enzymes involved in producing lactic acid of Lactobacillus delbrueckii subsp.Bulgaricus

以四株德氏乳杆菌保加利亚亚种为出发菌株,详细比较了四株菌产酸关键酶酶活的差异,从而找出菌株KLDS1.1006和KLDS1.1011后酸化较弱的主要原因及控制其产酸的关键酶。结果表明,H^+-ATPase可以控制菌株的能量代谢,是产酸关键酶;β-半乳糖苷酶对于分解乳糖产酸的贡献非常大,是乳糖代谢关键酶;乳酸脱氢酶和蛋白酶与后发酵产酸过程并没有必然联系;H^+-ATPase和β-半乳糖苷酶酶活性较弱是引起菌株KLDS1.1006和KLDS1.1011后酸化程度弱的根本原因。

Four Lactobacillus delbrueckii subsp, bulgaricus studied the enzymes of metabolic pathway from lactose to strains were regarded as the research subject, lactic acid and H＊-ATPase,to find which enzyme was the most important one that results in postacidification of yogurt,and the reason why KLDSI.1006 ang KLDS 1.1011 had a weak postacidification character. The key enzymes of Lactobacillus delbrueckii subsp. bulgaricus played important roles in producing lactic acid were l^-galactosidase and H ^-ATPase. Lactate dehydrogenase and protease showed no obvious correlation with postacidification. The enzyme activities of 6- galactosidase and H ATPase were weak,which was the fundamental reason why KLDSI.1006 and KLDS 1.1011 reflected weak postacidification.