树脂D201上粗漆酶的固定化及对孔雀石绿的脱色

云芝粗漆酶以3种方法,即静电吸附法(D201-Lac-Ⅰ)、先吸附后交联法(D201-Lac-Ⅱ)、戊二醛处理树脂后吸附法(D201-Lac-Ⅲ)固定到大孔阴离子交换树脂D201上.与静电吸附法相比,D201-Lac-Ⅱ的漆酶固载量大幅提升至4.65倍,漆酶比活力却严重受损,只有前者的4.8%;D201-Lac-Ⅲ的漆酶固载量略有下降,为静电吸附法的0.51倍,漆酶比活力却显著提高至静电吸附法的2.99倍.利用电子透射电镜(TEM)可明显观察到D201-Lac-Ⅲ漆酶分子聚合体的阴影.用D201-Lac-Ⅲ对孔雀石绿进行了连续多批次脱色试验,在长达210 h的连续操作中,其脱色效率未观察到有下降趋势,一直稳定在40%～55%之间,D201-Lac-Ⅲ的酶活亦未观察到下降,同等条件下游离的漆酶活力已损失至20%以下,证明D201-Lac-Ⅲ具有显著提升的稳定性和优良的重复利用性.考虑到粗漆酶廉价易得,D201-Lac-Ⅲ在水处理应用中可能大有前景.

Immobilization of Crude Laccase onto Anion Exchange Resin and Its Application in Decoloration of Malachite Green

Crude laccase from Trametes versicolor was immobilized onto anion exchange resin D201 by three methods,i.e.,direct electrostatic adsorption(D201-Lac-Ⅰ),crosslinking after electrostatic adsorption(D201-Lac-Ⅱ) and electrostatic adsorption after treating D201 with glutaraldehyde(D201-Lac-Ⅲ).Compared to direct electrostatic adsorption,the immobilized laccase amount of D201-Lac-Ⅱ increased by 4.65 times but the laccase activity was decreased to 4.8%,while the laccase activity on D201-Lac-Ⅲ increased by 2.99 times,with the immobilization amount decreased to 51%.Shadows of laccase aggregation on D201-Lac-Ⅲ were found by transmission electron microscopy(TEM).Continuous batch decoloration of malachite green demonstrated that the decoloration efficiency of D201-Lac-Ⅲ remained in the range of 40% to 55% for more than 210 hours,in addition,the enzyme activity on D201-Lac-Ⅲ maintained unchanged while the activity of free laccase declined to less than 20% under the same condition.All of the results above indicated that D201-Lac-Ⅲ had a significantly enhanced stability and good reusability.Considering the low price and simple production procedure of crude laccase,D201-Lac-Ⅲ could be promising for water treatment purpose.