γ-聚谷氨酸的分离与纯化
毕业论文关键词 γ-聚谷氨酸 纳豆芽孢杆菌 微生物发酵 分离 纯化
Title Isolation and purification of γ-poly glutamic acid Abstract γ-PGA is natural and water soluble polymers of glutamic acid, a kind of polypeptide molecule derived from microorganism fermentation and synthesized by forming gamma-amide bond of L-, and D-glutamic acid, and found in the capsule of anthrax bacillus cells as early as 1913. Due to its good water imbibition, biocompatibility and biodegradability, the microbial synthesis of gamma- PGA, a kind of high molecular weight polymer, are widely used in various industries including food, drug and environmental protection. At present, despite Bacillus natto microorganism fermentation is the mainstream methods to produce gamma - PGA，however, the major problem of this processes is the simultaneous initiation of synthesis and degradation process. To overcome this problem, we firstly selected Bacillus natto strain with high protein synthetase activity, and secondly obtained the optimal components of culture media and optimal culture conditions by analysis the key factors effect on fermentation, such as Compounded Carbohydrate, Environmental pH value, and Salting Concentration. Finally, we also isolated and purified the γ-PGA from the gamma - PGA crude products derived from thus optimal conditions.
Keywords γ-PGA Bacillus natto Microbial fermentation Isolation Purification
目录
中文摘要 Ⅰ
Abstract .. Ⅱ
1.引言 6
1.1 纳豆芽孢杆菌 6
1.2 聚谷氨酸 . 6
1.2.1聚谷氨酸的化学结构 6
1.2.2聚谷氨酸的立体化学结构 . 7
1.2.3 聚谷氨酸的生物合成 .. 8
1.2.4 聚谷氨酸的提取 . 8
1.2.5 聚谷氨酸的应用 . 9
1.3 课题研究意义 .. 10
2 实验方法 . 11
2.1 菌株的筛选 . 11
2.2 聚谷氨酸的发酵生产 12
2.2.1实验试剂 12
2.2.2实验仪器 13
2.2.3培养基和培养条件 .. 14
2.2.4最佳发酵培养基成分和培养条件优化实验 . 15
2.3 发酵液的处理 15
2.4γ-聚谷氨酸的提取 . 15
2.5 分析方法 .. 16
2.5.1 SDS-PAGE 电泳 16
2.5.2谷氨酸钠的紫外可见光分光光度检测方法 . 17
3.结果与分析 18