枯草芽孢杆菌C-36纤维素酶的纯化及酶学性质

Purification and Properties of Cellulase from Bacillus subtilis C-36

枯草芽孢杆菌C-36纤维素酶经硫酸铵、SephadexG-75、SephadexG-100分离纯化后,得到一个电泳纯的葡聚糖内切酶。SDS-PAGE结果表明,该酶分子量约为35kD。最适反应温度和pH分别为65℃和pH6.8,Zn2+、Pb2+、Fe3+对酶有抑制作用,Ba2+、Fe2+对酶有激活作用,在50℃,pH6.8条件下,酶对CMC-Na的米氏常数Km为0.34g/L,最大反应速度Vmax为0.17mg/(min.mL)。

A cellulase from Bacillus subtilis C- 36 was isolated and purified, by means of ammonium sulfate precipitation, followed by chromatography on Sephadex G- 75 and Sephadex G- 100. Analysis shows that the purified cellulase is CMCase. SDS- PAGE shows its molecular weight is about 35 kD. The optimum temperature is 65 ℃, and the optimum pH is pH 6.8. The cellulase can be inhibited by Zn^2 ＋, Pb^2 ＋, Fe^3 ＋ and activated by Ba^2 ＋ , Fe^2 ＋. Its Km for CIVIC- Na at 50 ℃ and pH 6.8 is 0.34 g/L.