高山梨醇脱氢酶活力氧化葡萄糖酸杆菌的培养条件优化
高山梨醇脱氢酶活力氧化葡萄糖酸杆菌的培养条件优化(任务书,开题报告,外文翻译,论文11500字)
摘要
氧化葡萄糖酸杆菌细胞膜脱氢酶迅速不完全氧化底物的特性使其在合成糖衍生物的工艺中被广泛应用。其细胞膜上的山梨醇脱氢酶在生产维生素C和制备L-山梨糖等方面有重要的应用。
本实验从中国普通微生物保藏中心所购买的菌种出发，在此次研究中，对所购买的菌种进行了活化并筛选出单菌落与斜面保藏用于后期实验，并对山梨糖含量的测定方法进行了确定。同时对菌株发酵培养基及发酵条件进行了探究，改变其碳源、氮源、金属离子的种类及其浓度，还有发酵的温度及培养基pH。为了获取生物量和山梨醇脱氢酶活性最高的培养条件，运用单因素实验法和正交实验法培养条件进行优化。通过实验发现，培养基的最适成分为山梨醇、酵母浸粉、磷酸氢二钾和硫酸镁；对应的山梨醇浓度为20.0g/L、酵母浸粉浓度3.0g/L、磷酸氢二钾浓度3.5g/L、硫酸镁浓度1.0g/L、谷氨酸钠1.0g/L；培养条件为30℃、150r/min；培养基的初始pH为自然pH。优化培养条件后所发酵培养的氧化葡萄糖酸杆菌的生物量达到了1.08g/L，较优化之前提高了21.3%；山梨醇脱氢酶总活力为1.12U/mg，较优化之前提高了25.8%。
关键词：氧化葡萄糖酸杆菌 山梨醇脱氢酶 发酵优化
Optimization of culture conditions for the activity of sorbitol dehydrogenase in Oxidized Gluconobacter
Abstract
Gluconobacter oxydans is a specialized aerobic gram-negative bacterium belonging to the family Acetobacter. The rapid incomplete oxidation of the cell membrane makes it widely used in the process of synthesizing sugar derivatives. Sorbitol dehydrogenase on cell membranes has applications in the production of vitamin C and preparation of L-sorbose.
In this study, starting from the strains purchased by the China General Microbiological Culture Center, in this study, the purchased strains were activated and screened for single colonies and slopes for subsequent experiments and determination of sorbose content. The method was determined. At the same time, the fermentation medium and fermentation conditions of the strain were investigated to change the carbon source, nitrogen source, metal ion species and their concentrations, as well as the fermentation temperature and the pH of the culture medium. In order to obtain the highest culture conditions for biomass and sorbitol dehydrogenase activity, single factor experiments and orthogonal experiments were used to optimize the culture conditions. Through experiments, the optimum components of the medium were sorbitol, yeast extract, dipotassium phosphate and magnesium sulfate; the corresponding sorbitol concentration was 20.0 g/L, the yeast extract concentration was 3.0 g/L, and dipotassium hydrogen phosphate was used. Concentration 3.5g/L, magnesium sulfate concentration 1.0g/L. The culture conditions were 30°C, 150 r/min; the initial pH of the medium was natural pH. After optimization of culture conditions, the biomass of gluconobacter oxydans that had been fermented after fermentation was 1.08g/L, which was 21.3% higher than that before optimization. The total activity of sorbitol dehydrogenase was 1.12U/mg, which was 25.8% higher than that before optimization.
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Key Wodrs：G.oxydans; Sorbitol dehydrogenase; Fermentation optimization
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目录
摘要 I
Abstract II
第一章 文献综述 1
1.1氧化葡萄糖酸杆菌简介 1
1.1.1氧化葡萄糖酸杆菌的生长特性 1
1.1.2不完全氧化底物的特性 1
1.1.3静息细胞作为反应酶源的稳定性 2
1.2氧化葡萄糖酸杆菌的应用 2
1.2.1制备米格列醇 2
1.2.2制备维生素C 2
1.2.3制醋工业的应用 3 [版权所有：http://DOC163.com]
1.2.4生产二羟丙酮 3
1.3氧化葡萄糖酸杆菌的代谢 3
1.4研究内容及意义 5
第二章 材料和方法 6
2.1实验材料 6
2.1.1实验仪器 6
2.1.2实验试剂 6
2.1.3菌种 7
2.1.4培养基配方及缓冲液配置 7
2.2实验方法 8
2.2.1真空冷冻保藏菌的恢复培养 8
2.2.2氧化葡萄糖酸杆菌的培养 8
2.2.3高山梨醇脱氢酶活力菌株的分离筛选 8
2.2.4山梨醇脱氢酶的活力测定 9
2.2.5生物量测定 11
第三章 结果与讨论 12
3.1高山梨醇脱氢酶活力菌株的筛选 12
3.2发酵培养基成分的研究 12
3.2.1碳源种类和浓度的探究 12
3.2.2氮源种类及浓度的探究 14
3.2.3无机盐种类的探究 15
3.3正交实验探究培养基最适配方 16
3.4培养条件对菌体细胞生物量和山梨醇脱氢酶活力的影响 18
3.4.1培养基初始pH的影响 18
3.4.2培养温度的影响 19
第四章 结论与展望 21
4.1结论 21
4.2展望 21
参考文献 22
致谢 24