保加利亚乳杆菌产酸关键酶的研究

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。 

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

Four Lactobacillus delbrueckii subsp.bulgaricus strains were regarded as the research subject, studied the enzymes of metabolic pathway from lactose to lactic acid and H～+-ATPase, to find which enzyme was the most important one that results in postacidification of yogurt, and the reason why KLDS1.1006 ang KLDS 1.1011 had a weak postacidification character.The key enzymes of Lactobacillus delbrueckii subsp.bulgaricus played important roles in producing lactic acid wereβ-galactosidase and H～+-ATPase.Lactate dehydrogenase and protease showed no obvious correlation with postacidification.The enzyme activities ofβ-galactosidase and H～+-ATPase were weak, which was the fundamental reason why KLDS1.1006 and KLDS 1.1011 reflected weak postacidification.