纳豆制备过程中大豆异黄酮糖苷酶的性质研究

目的]研究大豆异黄酮糖苷酶的反应特性。方法]以纳豆菌为供试菌株发酵大豆,从发酵液中提取大豆异黄酮糖苷酶,以大豆异黄酮为酶作用底物进行反应,研究底物浓度、反应时间、反应温度及pH值对酶反应的影响。结果]底物浓度为2%时,生成的产物（苷元）量最多;反应时间为20h时生成的产物量最多,当反应时间超过20h后,随着反应时间的延长产物量无明显变化;反应温度为40℃时产物量最多,当反应温度超过40℃时,产物量减少;pH值为5.0时生成的产物量最多。结论]大豆异黄酮糖苷酶反应的最佳条件为：底物浓度2%,反应温度40℃,pH值5.0,反应时间20h。

Study on Properties of Soybean Isoflavone-glycosidase in Preparation Process of Natto

Objective] The aim was to study the reaction characteristics of soybean isoflavone-glycosidase. Method] The soybean was fermented with bacillus natto as the tested strain and the soybean isoflavone-glycosidase was extracted from the fermentation broth. After that the enzyme reaction was conducted with soybean isoflavone as the substrate. The effects of substrate concn.,reaction time,reaction temperature and pH value on the enzyme reaction were studied. Result] When substrate concn. was 2% the product (ag...