包埋法固定化大肠杆菌细胞的研究+文献综述
关键词：细胞固定化；海藻酸钠；包埋法
Studies on the immobilization of E. coli cells by entrapment method
Abstract：Organic acids are important intermediates in organic synthesis, using nitrilase to enzyme catalyzed the synthesis of organic carboxylic acids has great advantages. Such as mild reaction conditions, less pollution and ease of handling, etc. It also can achieve highly chemoselective, regioselective and stereoselectivity which are not achieved by general chemical method. Free cells which produce nitrilase are unstable, unable to meet the industrial demand. Immobilization method is used to improve the stability of the cell. This paper uses the entrapment method which is the most common. Try to use the entrapment method to immobilize E. coli cells, producing important intermediate nitrileacid. Try to find the optimum entrapment conditions through different trials. After systematic optimization of the entrapment condition, the optimal sodium alginate concentration is 3%, the concentration of calcium chloride is 0.3 M, and the hardening time is 2 hours. The optimum reaction pH value of immobilized cell is 7.5, and the cells in this condition are stable. Immobilized cell’s activity is 68.0% of free cells.
Keywords: Cell immobilization; sodium alginate; Entrapment
目 录
1 研究背景 1
1.1 腈水解酶 1
1.1.1 腈水解酶简介 1
1.1.2 腈水解酶作用机制 1
1.1.3 腈水解酶的应用 2
1.1.4 腈水解酶的制备 3
1.2 细胞固定化的研究意义 4
1.3 细胞固定化制备方法 4
1.3.1 吸附法 5
1.3.2 共价结合法 5
1.3.3 交联法 5
1.3.4 包埋法 5
1.4 固定化细胞的应用进展 6
1.4.1 工业上的应用 6
1.4.2 环境保护方面的应用 6
1.5 本课题研究的意义及思路 7
2 实验的技术路线和流程 9
3 试验方法与材料 10
3.1 实验材料 10
3.1.1 菌株 10
3.1.2 培养方法 10
3.1.3 主要试剂 10
3.1.4 主要仪器 11
3.2 试验方法 11
3.2.1 固定化细胞 11
3.2.2 海藻酸钠固定化细胞优化 12
3.3 酶活测定方法 13
3.3.1 OD值测定方法 13
3.2 酶活测定方法 13
3.3.3 酶活计算方法 14
4 结果与讨论 15
4.1 标准曲线 15
4.2不同方法测得的酶活 15
4.3 海藻酸钠浓度对细胞的影响 16
4.4 氯化钙浓度优化 17
4.5 硬化时间优化 18
4.6 缓冲溶液pH值优化 19