精氨酸酶工程菌发酵条件的研究
时间:2018-04-03 21:37 来源:毕业论文 作者:毕业论文 点击:次
| 摘要本文研究了工程菌纯菌株pET30a-hA I将精氨酸转化成鸟氨酸的关键影响因素及培养条件，还探索了对菌体细胞进行海藻酸钠-聚乙烯醇固定化处理，以实现鸟氨酸制备工业化。在摇床条件下， 菌浓为0.0285g/mL 的发酵液，可在24h内完全转化所有0.25%精氨酸，转化率较低。在对发酵条件进行探索后，最终确定在pH为中性时产率较高，加入表面活性剂Tween-80后可缩短发酵时间至21h。以及对发酵过程中菌浓的变化情况，进行了检测，采取加入硫酸铵和乳糖的方法缓解菌体对鸟氨酸的消耗，但是结果并不太理想。最后是将菌体与海藻酸钠和聚乙烯醇体系混匀，滴入氯化钙成球，再在硼酸中浸泡，得到固定化细胞的颗粒，让其发酵0.25%的精氨酸溶液，反应时间延长至120h。本文的研究结果表明，该菌株有很高的精氨酸酶活性，能进一步研究其反应条件及固定化，实现工业化大规模生产。20558 关键词：精氨酸酶 发酵 固定化 工程菌 毕业论文设计说明书（论文）外文摘要 This paper studies the key influencing factors and culture conditions of pure engineering bacterium strains,pET30a - hA I, which would put arginine into ornithine, and explores the immobilized processing of bacteria cells with sodium alginate and polyvinyl alcohol in order to realize the industrialization of Ornithine preparation. Under the condition of the shaking table, fermented liquid of which bacteria concentration is 0.0285 g/mL of, can completely convert all 0.25% arginine within 30 h, but conversion rate is low. After the exploration of the fermentation conditions, the pH to neutra determine the yield is higher, and after joining surfactant Tween - 80 fermentation time can shorten to 22 h. Then the change of bacteria concentration in the fermentation process is tested, the method to add ammonium sulfate and lactose is to ease the consumption of ornithine by bacteria, but the result is not good. Finally, blend the bacteria with sodium alginate and polyvinyl alcohol system, drip them into the calcium chloride into a ball, then soak in boric acid, achieve the particles of immobilized cells, then let its fermentation in 0.25% arginine solution. The reaction time increased to 120 h. In this paper, the research results show that the strain has high arginine enzyme activity, the reaction conditions and immobilized processing can be further study, to realize the industrial mass production. Keyword: arginase fermentation immobilization engineering-bacteria 目 次 1 引言 1 1.1鸟氨酸 1 1.2 L-ORNITHINE的合成生产现状 2 1.3 国外L-ORNITHINE发酵研究的发展 2 1.4 国内L－ORNITHINE发酵研究的进展 3 1.5 本课题的提出 3 2 性质及检测 4 2.1发酵原料L-ARGININE和发酵产物L-ORNITHINE 4 2.2 茚三酮法检测氨基酸 4 3 薄层层析 6 3.1 薄层层析原理和特点 6 3.2 展开剂的选择 6 4 菌种培养 9 4.1 菌种来源 9 4.2 培养基配制 9 4.3 菌种的活化 10 4.4 摇瓶培养 10 4.5 菌浓的测定 11 5 发酵条件优化 12 5.1溶液配制： 12 5.2 实验基本操作 12 5.3实验探索过程 12 6 细胞的固定化 18 结论： 20 (责任编辑：qin) |