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采用吸附-交联的方法获得凹凸棒土固定的β-葡萄糖苷酶,酶的固载量为147 mg/g,表观酶活为87.5 U/g。固定后,酶在加入叔丁醇混合溶剂中催化合成辛基葡萄糖苷的催化效率显著提高,葡萄糖转化率提高80.6%。在反应温度为50℃,p H为6.5,葡萄糖浓度为0.05 mol/L,V(辛醇)∶V(叔丁醇)∶V(水)=8∶1∶1的反应条件下,葡萄糖转化率可达到20.4%,反应达到平衡的时间从自由酶催化反应的120 h缩短至72 h。反应动力学研究表明,葡萄糖对酶催化反应具有底物抑制作用,通过固定化可提高酶耐受底物抑制的最大葡萄糖浓度,增加最大反应速率。固定酶在重复使用3次后酶活下降70%。
The β-glucosidase immobilized on attapulgite was obtained by adsorption-crosslinking method. The immobilized amount of enzyme was 147 mg / g and the apparent enzyme activity was 87.5 U / g. After immobilization, the catalysis efficiency of catalyzing the synthesis of octylglucoside by adding tert-butanol into the mixed solvent was significantly increased, and the glucose conversion rate was increased by 80.6%. Under the reaction conditions of a reaction temperature of 50 ° C, p H of 6.5, a glucose concentration of 0.05 mol / L, V (octanol): V (t-butanol): V The rate can reach 20.4%, and the time for the reaction to reach equilibrium is shortened from 120 h of free enzyme reaction to 72 h. Reaction kinetics studies show that glucose has a substrate inhibitory effect on the enzyme-catalyzed reaction, and immobilization can increase the maximum glucose concentration inhibited by the enzyme-tolerant substrate and increase the maximum reaction rate. Immobilized enzymes decreased by 70% after being reused 3 times.