论文总字数：20260字

摘 要

近年来，在光催化领域中，人们将更多目光投向了纳米-介孔TiO₂材料的应用。因为这种材料比表面积大，表面富含羟基，化学性能稳定，机械强度高，能够提供很好的固定化酶操作平台。本课题将由链霉菌 Streptomyces albulus PD-1菌株合成的聚阳离子生物材料ε-聚赖氨酸应用于生理学pH下改性TiO₂。ε-聚赖氨酸有很多优良特性，例如生物相容性、热稳定性、水溶性等，并且还具有ε位游离氨基。ε-聚赖氨酸的存在可以改善载体和酶的生物相容性，同时，采用静电吸附，将蔗糖异构酶固定在改性介孔TiO₂上，通过不断改进固定化研究条件，使得固定化酶的酶活及吸附强度有了显著提高。

本论文研究了TiO₂的改性方法、固定化酶的催化特性及其酶学性质，为制定更详细、更高效的固定化蔗糖异构酶在食品工业中经济生产异麦芽酮糖的合理策略提供机会。

关键词：ε-聚赖氨酸 蔗糖异构酶 固定化酶 TiO₂

Study on the Surface Modification of Mesoporous titanium dioxide

with ε-poly-lysine for Sucrose isomerase Immobilization

Abstract

In recent years, nano materials and mesoporous TiO₂ materials were used in the field of photocatalysis, which has attracted much attention. These kinds of materials have great specific surface area, stable chemical properties, high mechanical strength, rich in hydroxyl, provide a good background for the operation of the immobilized enzyme. ε-poly-L-lysine (EPL), one of the polycation biological materials, was used to modify M-TiO₂ in physiological pH solutions, which was synthesized by Streptomyces albulus PD-1 strain. EPL has several advantages such as good bio-compatibility, good heat stability, water solubility, and also exhibits a unique structure linking α-carboxylic and ε-amino groups and has free amino groups. The existence of the EPL can improve the bio-compatibility of carrier and enzymes, at the same time, enhance the adhesion strength of the carrier and the enzyme. The modified method of M-TiO₂, the properties of immobilized enzyme and the catalytic characteristics of immobilized enzyme were investigated in this paper.

This paper briefly discusses the method of TiO₂ modified, the catalytic properties of immobilized enzyme and its enzymatic properties. Moreover, the idea is to provide a chance for the rational strategy of a more specific and efficient immobilized enzyme for economical production of isomaltulose in food industry.

Key Words: Sucrose isomerase; Immobilized enzyme; immobilization conditions; TiO₂

目录

摘 要 I

Abstract II

第一章 文献综述 1

1.1蔗糖异构酶 1

1.2异麦芽酮糖和海藻酮糖 1

1.3固定化酶 1

1.3.1酶的固定化方法 2

1.3.2酶固定化的载体 3

1.3.3固定化酶的评价指标 3

1.3.4固定化酶的性质 3

1.4TiO₂ 4

1.5 ε-聚赖氨酸改性介孔TIO₂ 4

第二章 蔗糖异构酶的纯化 5

2.1材料与方法 5

2.1.1实验菌种 5

2.1.2实验试剂与仪器 5

2.1.3培养基及培养条件 6

2.1.4SIase的获得及酶活测定 6

2.2结果与讨论 8

2.2.1异麦芽酮糖标准曲线 8

2.2.2蛋白标准曲线 9

2.2.3 SIase的纯化 9

第三章 酶的固定化、M-TiO₂官能团改性和酶学性质的研究 9

3.1 材料与方法 10

3.1.1 材料 10

3.1.2方法 10

3.2实验结果与讨论 12

3.2.1 M-TiO₂官能团化改性的研究 12

3.2.2固定化条件的研究 12

3.3酶学性质研究 16

3.3.1反应最适pH 16

3.3.2反应最适温度 17

3.3.3 pH稳定性 17

3.3.4温度稳定性 18

3.4米氏常数K_m和最大反应速率V_max 18

3.5反应进程曲线 19

3.6固定化酶SI-EPL-TiO₂完全反应时间的确定、批次反应次数与半衰期的确定（固定化酶SI-EPL-TiO₂重复酶催化反应） 19

第四章 结果与讨论 21

4.1 结论 21

4.2 展望 21

参考文献 22

致 谢 24

第一章 文献综述

1.1蔗糖异构酶

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