固定化酶水解植物蛋白的条件研究及其固定床的探索

论文编号:ZY098    论文字数:10008,页数:23

摘 要：酶具有专一性强，催化效率高和作用条件温和等显著特点，但是在酶的使用过程中，人们也注意到了酶的一些不足之处：（1）稳定性差；（2）一次性使用；（3）产物的分离纯化较困难。为此，固定化技术在这一领域的应用越来越广泛。
 本实验采用海藻酸钠作为载体包埋固定化中性蛋白酶。探索了中性蛋白酶在海藻酸钠中的固定化技术，并对影响固定化酶活性的因素进行了研究。通过改变固定化的制作条件，确定最佳的固定化参数。实验表明，固定化酶的质量受多方面因素的影响，在最适pH和温度一定的情况下，以海藻酸钠的浓度、固定化酶量、固定化时间以及大豆蛋白液底物浓度这4个因素的影响最大，并对这些因素进行单因素分析，得出最佳底物浓度（大豆：水）为1：7；最适固定化时间为2.5h；最适酶浓度（酶量w：海藻酸钠溶液体积v）为1%；最适海藻酸钠浓度(w/v)为3%。
 并在此最佳单因素条件下，比较了固定化中性蛋白酶在摇床和固定床中的水解效果，结果表明：在固定床中与在摇床中的水解效果相差不大，但在固定化酶使用次数和时间方面有很大的改善，从而使得酶的利用率更高；而且实现批量或连续操作模型的可能，更适于产业化、连续化、自动化生产。
关键词：海藻酸钠；固定化；中性蛋白酶;植物蛋白；固定床

Abstract: Enzyme has many outstanding characteristics, such as powerful specificity, high catalyzing efficiency and moderate action conditions. However, on the process of using enzyme, people have already awared its limitations:(1)poor stability;(2)one-off using;(3)difficult separating and sublimating of products. So the immobilizing techniques in this area are used more and more extensive.
  In this experiment, sodium alginate is used as carrier to immobilize neutral prolease, immobilizing technique of neutral prolease with sodium alginate is quested, and the factors which influence activity of neutral prolease is studied. Optimal immobilizing parameter is definited by changing the conditions of immobilization. The experiment indicates: the quality of immobilized enzyme is influenced by many factors. Under the circumstances of optimal pH and optimal temperature definited, sodium alginate concentration, the concentration of immobilized enzyme, immobilizing time and the concentration of soybean protein solution are the most important factors. So these factors are studied with monofactorial method. And the study obtains: the optimal concentration of base solution (soybean: water) is 1:7; the optimal immobilizing time is 2.5h; the optimal concentration of enzyme(the dosage of enzyme: the volum of sodium alginate solution) is 1%; the optimal concentration of sodium alginate (w/v)is 3%.
 And under these optimal monofactorial conditions, the effect of hydrolysis in the fixed-bed is compared with in the shaker. The experiment reveals: the effect of hydrolysis in the fixed-bed is similar to the effect in the shaker. However, on the frequency and time of utilization, there is a significant improvement. And hydrolysis in the fixed-bed is more possible to achieve continuous or batch operation, it’s more suitable to be industrialized, continuous and automatous.
Key words: Sodium alginate; immobilize; neutral prolease; plant protein; fixed-bed

目  录
中文摘要 I
英文摘要 II
目录 III
1. 绪论 1
 1.1 大豆蛋白的研究背景 1
 1.2 固定化酶的研究背景 1
     1.2.1 酶固定化的方法 1
     1.2.2 固定化酶的应用 2
 1.3 固定化酶水解大豆蛋白的优势 3
2. 实验部分 4
 2.1 材料与准备工作 4
 2.1.1 实验材料与仪器设备 4
 2.1.2 准备工作 5
  2.2 实验方法 6
 2.2.1 酶的固定化方法 6
 2.2.2 自制固定床的安装 7
 2.2.3 游离氨基的测定方法 7
 2.2.4 实验流程 8
3. 结果与讨论 9
  3.1 NaOH标准溶液的浓度 9
  3.2 空白溶液的滴定 9
  3.3 固定化酶与游离酶的性能比较 9
  3.4 单因素实验确定固定化条件 10
 3.4.1 海藻酸钠浓度对酶固定化的影响 10
 3.4.2 固定化时间对酶固定化的影响 11
 3.4.3 固定化酶浓度对水解效果的影响 12
 
 3.4.4 底物浓度对水解效果的影响 13
  3.5 固定化酶在固定化床与摇床中的比较实验 14
 3.5.1 固定化酶在固定床与摇床中的性能比较 14
 3.5.2 固定化酶在固定床与摇床中水解效果的比较 15
  3.6 实验中的注意点 16
4. 总结与展望 17
  4.1 总结 17
  4.2 展望 17
致谢 18
参考文献 19