【摘要】 采用吸附法与溶胶-凝胶(sol-gel)包埋法固定化醇脱氢酶(ADH),对两种方法固定化的ADH的活性进行了比较。采用大孔硅胶为载体对ADH进行吸附,研究了吸附动力学和吸附平衡,得到了吸附动力学曲线和吸附等温线,ADH在硅胶上的吸附等温线可以用Langmuir方程拟合。并且考察了硅胶孔径对ADH吸附量的影响,发现大孔径的硅胶对ADH有着较大吸附量。同时采用sol-gel法对ADH进行包埋固定化。在pH7.0、25℃下,对两种固定化酶催化甲醛转化为甲醇的反应活性进行比较。由实验测得的反应初速度及拟合得到的米氏常数表明吸附法固定化ADH表现出比sol-gel法固定化ADH高的催化活性。更多还原

【Abstract】 Alcohol dehydrogenase (ADH) is respectively immobilized onto macroporous silica carrier by adsorption and into microporous silica gel by sol-gel encapsulation. Through the study of adsorption kinetics and adsorption equilibrium, the kinetics curve and adsorption isotherm are obtained. And the adsorption isotherm is fitted by Langmuir equation. The effect of pore size on the adsorption capacity is examined. The sol-gel encapsulated ADH is prepared with silica matrix. The catalytic activity of the above-mentioned immobilized ADH towards the conversion of formaldehyde into methanol is compared under pH=7.0, 25℃. Under the same conditions, the initial rates of enzymatic reaction catalyzed by adsorption immobilized ADH is higher than that catalyzed by sol-gel encapsulated ADH, whereas the Michaelis constant of the former is less than that of the latter. These results indicates that the catalytic activity of adsorption immobilized ADH is higher than that of sol-gel encapsulated ADH.更多还原