海藻酸钙固定化葡萄糖淀粉酶的研究.docVIP

毕业设计（论文）  PAGE \* MERGEFORMAT  摘 要 本次研究采用的是海藻酸钠为载体，利用包埋法固定葡萄糖淀粉酶。研究得出了制备时的给酶量、氯化钙浓度、形成时间对固定化酶的影响，在此基础上，也进一步研究了固定化酶的米氏常数和重复使用稳定性。 在单因素实验基础上，通过三因素三水平正交试验得出，氯化钙浓度为2%，形成时间为3.5h，给酶量为22mg是最佳组合，单位质量的酶活力为12151U/g。游离酶的Km为2.50mg/ml，固定化酶的Km为3.63mg/ml。通过固定化之后，酶对底物的亲和力降低了。随着使用次数的增加，酶活性逐渐降低，但是每次反应10min，在使用10次之后，酶活性还有原来的50%。 关键词：海藻酸钠；葡萄糖淀粉酶；固定化酶 PAGE \* MERGEFORMAT I Abstract This study uses the sodium alginate as the carrier, the glucamylase was immobilized using the method of embedding . In this experiment, we know the influence of the amount of enzyme, concentration of calcium chloride and curing time on immobilized enzyme. On this basis, we make further study on Michaelis constant and the stability of repeated use of the immobilized enzyme. On the basis of single factor experiment, we do the three factors and three levels orthogonal test. When the concentration of calcium chloride is 2%, the curing time is 3.5h and the amount of enzyme is 22mg, we can get the best combination, unit mass of enzyme activity is 12151 u/g. The Km of free enzyme is 2.50 mg/ml, the Km of immobilized enzyme is 3.63 mg/ml. After the immobilization, enzyme reduces the affinity to the substrate. With the increase of use, enzyme activity decreases gradually. Immobilized enzyme retained 50% activity after 10 reuses with 10 min of each reaction time. Keywords: calcium alginate; glucamylase; immobilized enzyme  PAGE \* MERGEFORMAT I 目 录 TOC \o 1-3 \h \u  HYPERLINK \l _Toc2722 摘 要  PAGEREF _Toc2722 I  HYPERLINK \l _Toc3834 Abstract  PAGEREF _Toc3834 II  HYPERLINK \l _Toc31254 1 绪论  PAGEREF _Toc31254 1  HYPERLINK \l _Toc26636 1.1葡萄糖淀粉酶的简介  PAGEREF _Toc26636 1  HYPERLINK \l _Toc2366 1.1.1葡萄糖淀粉酶的性质  PAGEREF _Toc2366 1  HYPERLINK \l _Toc14748 1.1.2葡萄糖淀粉酶与淀粉的反应  PAGEREF _Toc14748 1  HYPERLINK \l _Toc11538 1.1.3葡萄糖淀粉酶与α-淀粉酶  PAGEREF _Toc11538 1  HYPERLINK \l _Toc17329 1.2酶固定化的方法  PAGEREF _Toc17329 1  HYPERLINK \l _Toc28865 1.2.1吸附法  PAGEREF _Toc2