白毒鹅膏菌胞外漆酶的部分酶学性质研究

Studies on Partial Character of Extracellular Laccase from Amanita verna

从威海市玛珈山上获得白毒鹅膏菌，在对其产酶条件研究的基础上，研究了pH值、温度、无机离子对白毒鹅膏菌漆酶活性和稳定性的影响，测定了漆酶的Km值。结果表明：Ba^2＋、Cu^2＋、、SO4^2-离子对漆酶有激活作用，而Ag^2＋、Cl^-、Fe^3＋离子则有抑制作用，该酶最适pH为4.6，在pH 5.0-5.4表现出较强的稳定性；最适反应温度为20℃，低于60℃时有较好的热稳定性；以邻联甲苯胺为底物的表观Km值为66.7μmol/L。

Amanita verna was screened from majia hill in weihai. The effect of pH value, temperature and inorganic ion on Amanita verna laccase activity and stability was studied in the paper. Meanwhile, the substrate concentration effect of this laccase is also studied and Km value is measured. The result showed that Ba2. , Cu^2＋ and SO4^2- increased laccase activity whereas Ag^＋ , Cl^-, Fe^3＋ obviously inhibited it. The optimal temperature and optimal pH of laccase reaction were at 20℃ and pH 4.6, the laccase was kept strongly active when the pH value was between 5.0 and 5.4, and the laccase could work continually under 60℃. The form view Km of laccase was 66.7μmol/L with o-Tolidine as substrate.