摘要
通过对发酵乳杆菌、植物乳杆菌、短乳杆菌所产谷氨酸脱羧酶(GAD)的酶学性质进行比较,分析酶反应温度、pH值、磷酸吡哆醛(PLP)浓度、酶浓度与酶活性的关系,并对高活性乳酸菌GAD酶的米氏常数进行测定。结果表明,3株乳酸菌GAD酶的最适温度为40℃,最适pH值为4.5,在PLP添加量为0.1mol/L时,对酶的促进作用达到最高,发酵乳杆菌Km值为0.05215mmol/L,最大反应速度Vmax=2.08μmol/min;短乳杆菌Km值为0.0243mmol/L,最大反应速度Vmax=1.01μmol/min。
The properties of glutamate decarboxylases（GADs） produced by Lactobacillus fermentum, Lactobacillus plantamm and Lactobacillus brevis were studied. The effects of temperature, pH, pyridoxal phosphate （PLP） concentration and GAD concentration on GAD activity were analyzed. Besides, the Michaelis-Menten constants of the high-activity GADs from lactic acid bacteria were determined. The results showed that the optimum temperature and pH of GADs from three lactic acid bacteria were 40℃ and 4.5 respectively. The maximum enhancement of GAD by PLP was achieved when PLP content was 0.1mol/L. The Km and Vmax ofL. fermentum GAD were 0.05215mmol/L and 2.08μmol/min respectively. And for L. brevis GAD, the Km and Vmax were 0.0243mmol/L and 1.01 μmol/min respectively.
出处
《中国酿造》
CAS
2012年第9期56-59,共4页
China Brewing
基金
贵阳市科学技术计划项目([2010]筑科农合同字第1-农-19号)
贵州省科学技术基金(黔科合J字[2011]2156号)
关键词
乳酸菌
酶学性质
谷氨酸脱羧酶
Γ-氨基丁酸
lactic acid bacteria
enzyme properties
glutamate decarboxylase
γ-amino butyric acid
