微反应器中固定化beta-葡萄糖苷酶的催化过程研究毕业论文
2022-02-22 20:12:37
论文总字数:19942字
摘 要
Beta-葡萄糖苷酶,又称Beta-D-葡萄糖苷葡萄糖水解酶。它属于纤维素水解酶类,能够水解葡萄糖苷键,将多糖化合物分解为单糖。通常酶催化比经典化学反应更不容易导致副产物的形成,这就使得酶是分析化学领域的有力工具。在使用酶时发生的主要问题源于其对非生理条件的相对敏感性和较高的价格。上述缺点可以通过酶的固定化来克服,使得生物催化剂的可以再利用,只要保持其活性。当正确地进行固定时,酶更稳定并且也更耐变性。固定化酶微反应器(IMER)可以连续操作,以及小型化、稳定性强等优点。
本论文首先使用分光法测定游离Beta-葡萄糖苷酶的酶活为5.940U/ml并测得该酶水解pNPG的反应时间为10min,最适pH为4.6,最佳温度为50℃。然后采用了毛细石英管作为微反应器载体,将Beta-葡萄糖苷酶固定在载体上制成微反应器,测得酶活为2.04µmol /h·m,并以pNPG作为反应底物探究酶促反应的催化过程,通过单因素分析方法来确定对酶促反应的影响因素如:pH,反应温度等等,从而确定了反应最适pH为4.8、最适温度为50℃,底物的最适浓度为15mM/L,底物流速为7μL/min,实验证明固定化酶微反应器具有良好的稳定性和耐压性。
关键词:微反应器 固定化酶 催化 Beta-葡萄糖苷酶 pNPG
Abstract
Beta-glucosidase, also known as Beta-D-glucoside glucohydrolase. It belongs to the cellulose hydrolytic enzymes, can hydrolyze glucoside bonds and the polysaccharide compounds into monosaccharides. It is commonly known that enzymatic transformations are considerably more specific than classical chemical reactions which usually lead to formation of byproducts. That is why the enzymes are a powerful tool in the field of analytical chemistry. The main problems occurring while working with enzymes stem from their relatively high price and sensitivity to non-physiological conditions. The above mentioned disadvantages may be overcome through enzyme immobilization which allows for reusing the biocatalyst as long as it retains its activity. When the immobilization is performed correctly the enzymes are more stable and also more resistant to denaturation. Immobilized enzyme microreactor (IMER) can be continuously operated, as well as miniaturization, stability and other advantages.
In this paper, the enzymatic activity of free Beta-glucosidase was 5.940U/ml by spectrophotometry. The reaction time was 10min, the optimum pH was 4.6, and the optimum temperature was 50 ℃. Then the capillary quartz tube was used as the microreactor carrier, and the Beta-glucosidase was immobilized on the carrier to prepare the microreactor. The enzyme activity was 2.04µmol /h·m and the enzymatic reaction was investigated with pNPG as the reaction substrate The optimum reaction conditions were as follows: pH, reaction temperature and so on. The optimum pH was 4.8 and the optimum temperature was 50 ℃. The results showed that the immobilized enzyme microreactor The device has good stability and pressure resistance.
Key words: microreactor ; immobilized enzyme ; catalyzed ; Beta-glucosidase ; pNPG
目录
摘要 I
Abstract i
第一章绪论 1
1.1固定化酶 1
1.1.1酶的简介 1
1.1.2Beta-葡萄糖苷酶 1
1.1.3固定化酶 1
1.1.4固定化酶方法 2
1.2固定化酶微反应器 3
1.2.1微反应器 3
1.2.2毛细石英管微反应器 3
1.3本论文的工作目标及意义 5
第二章游离Beta-葡萄糖苷酶酶活的测定 7
2.1前言 7
2.2实验部分 7
2.2.1试剂与材料 7
2.2.2仪器与设备 8
2.2.3计算酶活的判定依据 8
2.2.4 分析方法 8
2.2.5单因素实验初步探究反应条件 11
2.3结果与讨论 11
2.3.1时间对酶解的影响 11
2.3.2温度对酶解的影响 12
2.3.3pH对酶解的影响 13
2.4小结 14
第三章毛细管固定化酶微反应器的制备及催化研究 15
3.1前言 15
3.2实验部分 15
3.2.1试剂与材料 15
3.2.2仪器与设备 15
3.2.3毛细石英管酶微反应器的制备 16
3.2.4微反应器的应用 17
3.3酶学性质研究 19
3.3.1反应最适pH 19
3.3.2反应最适温度 19
3.4酶稳定性研究 20
3.4.1酸碱稳定性 20
3.4.2热稳定性 21
3.4.3操作稳定性 22
3.4.4储存稳定性 22
3.5小结 23
第四章结论与展望 24
4.1结论 24
4.1.1游离Beta-葡萄糖苷酶酶活的测定 24
4.1.2毛细管固定化酶微反应器的制备及催化研究 24
4.2展望 24
参考文献 25
致谢 28
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