Abstract: The research of extracting urease from soybean dregs was carried out in order to expand the way of urease localization. The research had established a full set of extracting urease from soybean dregs. By use of the method of salting out and organic solvent precipitation, the urease in the soybean dregs was extracted and refined through experiments of extraction and centrifuging, etc., and its yield rate was 0.1%. Meanwhile, the optimum condition of urease extracting was determined: the optimum extracting temperature was 50℃, the optimum acetone concentration was 50%, and the most suitable pH value was 7.0. By the principle of Nessler’s reagent colorimetric method, it was tested that the value of Michaelis constant (Km) was 4.11×10-2 mol/L and the value of enzyme activity in the urease solution of 1 mL was 18.63 U under the optimum conditions. Extracting urease from soybean dregs not only solves the problem of urease localization, but also improves the added value of soybean dregs. The result of the research brings good industrial values and economic benefits.

Key words: soybean dregs, urease, enzyme activity, Km, factors affecting enzyme activity

摘要： 为拓展脲酶的国产化途径，对黄豆豆渣中脲酶的提取进行了研究。建立了从黄豆豆渣中提取脲酶的全套流程，利用盐析法和有机溶剂沉淀法，通过浸提及离心等试验操作手段，将黄豆豆渣中的脲酶进行提取精制，产率为0.1%。同时确定了脲酶的最佳提取条件：其最佳浸提温度为50℃，最佳丙酮浓度为50%，最适pH为7.0。利用纳氏试剂比色法的原理，测得该脲酶在最佳实验条件下的米氏常数Km值为4.11×10-2 mol/L，1 mL脲酶溶液中的酶活力为18.63 U。从黄豆豆渣中提取脲酶，既可解决脲酶的国产化问题，又可提高黄豆豆渣的附加值，研究结果具有良好的工业价值和经济效益。

关键词: 黄豆豆渣, 脲酶, 酶活力, Km, 酶活影响因素