产生淀粉糖化酶菌株的分离以及酶性质的初步研究

Screening a Raw Starch-digesting Glucoamyas Strain and Study on Enzymology Properties

从霉变物、土壤、醋曲、醋醅等分离出四株产生淀粉糖化酶且酶活较高的菌株,选取酶活最高的菌株vin-1作为出发菌株,初步鉴定为Aspergillus niger,其生淀粉糖化酶活力达到342U/g(干曲),酶最适作用温度为55℃,酶在pH值3．5～4．5之间有较高的酶活,最适pH值为4．0,Ca^(2+)、Mg^(2+)对酶有一定的激活作用,而Fe^(2+)、K^+、Fe^(3+)、Cu^(2+)、Mn^(2+)都有较强的抑制作用,Mn^(2+)抑制作用最大,达到近50%。

4 strains that could prodace raw starch-digesting glucoamylase and have the higher enzyme activity are isolated from soil in vinegar factory, musty substance, vinegar dregs and vinegar grains. The highest raw starch-digesting glucoamylase activity strain-vin-1 isidentified as Aspergillus niger, whose raw starch-digesting glucoamylase activity is 342U/g, the optimum-temperature- and pHare determined as 55℃ and 4.0 Enzyme activity is higher in pH3.5-4.5. Ca^2＋ and Mg^2＋ have been activated for the enzyme, Fe^2＋, K^＋, Fe^3＋, Cu^2＋ and Mn^2＋ have been restrained for the enzyme, Mn^2＋ has largest restrainable function for the enzyme whose activity is loss approximately 50%.