关键词: 黄豆豆渣, 脲酶, 酶活力, Km, 酶活影响因素

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