轮纹大茎点菌葡糖淀粉酶部分酶学性质研究

轮纹大茎点菌在液体培养条件下产葡糖淀粉酶酶活很低,而在固态培养条件下酶活相对较高。对粗酶液中葡糖淀粉酶的部分酶学性质进行研究,结果表明,该酶的最适反应温度为50℃,30~50℃之间有较高活性;40℃以下稳定,50℃保温1 h酶活性损失60%以上。酶的最适pH为8.0,在pH 7.0~11.0之间有较高的酶活性:pH 5.0以下酶不稳定,活性迅速丧失,5.0~10.0之间酶相对稳定。K+、Fe2+、Ca2+对酶的活性基本没有影响,而Cu2+、Mg2+、Zn2+、Mn2+、Na+对酶的催化活性有激活作用,其中Mn2+激活作用最为强烈。

Characterization of Glucoamylase Isolated from Macrophoma kawatsukai Hara

The activity of glucoamylase from Macrophoma kawatsukai Hara was relatively higher in solid culture than that in liquid culture.Studies on the character of glucoamylase isolated from Macrophoma kawatsukai revealed that the optimum reaction temperature of this enzyme was 50 ℃,it was stable below 40 ℃,and over 60% of its maximum activity was lost at 50 ℃ for 1 hour.The enzyme had an optimum pH-value of 8.0 and was relatively stable under pH 5.0~11.0.The activity of the enzyme was unaffected by K+,Fe2+ and Ca2+,and activated by Cu2+,Mg2+,Zn2+,Na+,especially by Mn2+.