The study of colicin Ib production in an agitation tank by using recombinant Escherichia coli

• Main Authors: Liang, Li-Fan, 梁禮凡
• Other Authors: Yen, Hong-Wei
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/6afsex

碩士 === 東海大學 === 化學工程與材料工程學系 === 107 === In order to avoid the symptoms of diarrhea caused by the infection of the weaned piglets, the traditional method of feeding is to add antibiotics to the feed to enhance the health of the intestines, thereby indirectly helping to prevent diarrhea from weaned piglets. Past research and empirical evidence have shown that the use of selected feed additives for nutritional interventions can effectively prevent diarrhea from weaned piglets.Although antibiotics can prevent diarrhea from weaned piglets and also kill bacteria that are harmful to the body, those can also affect bacteria that are good for the body. When the beneficial bacteria in the body are reduced, some opioid-infected microorganisms, such as mold, may multiply and cause disease. 　　Meanwhile, the use of a large number of antibiotics can also cause environmental pollution problems, which in turn leads to the emergence of super-resistant bacteria. Therefore, the protein produced in this experiment will be used to replace the use of antibiotics, in addition to avoiding the symptoms of diarrhea in the weaned piglets. Compare to traditional chemical drugs, the absorption of the protein is faster and the effect is better. Also, it has less side-effects and the stability can be improved. It can effectively prevent diarrhea from weaned piglets and reduce the economic loss of pig industry. 　　This project is planned to explore the use of 5L stirred fermentation tank to cultivate Escherichia coli to change different cultivate conditions to observe growth conditions, carbon source, cultivate temperature, inoculum and dissolved oxygen, cultivate temperature, pH value. Effects on growth of Escherichia coli and activity of Escherichia coli. This study found that increasing the stirring speed(550 rpm), pressure(1.5 kg/cm2), and carbon source(40 g/L) can give the bacteria a good growth space, which can make our bacteria reach a higher density(OD=13.7), but the growth of the bacteria is too good, resulting in poor production of bacteriostatic protein and the protein bacteriostatic activity is relatively low just 213. In the induction, it is necessary to change the growth conditions of the cells, so that the cells can effectively induce the reaction to produce the required protein, and the dissolved oxygen(5 %), temperature(26℃) and pH value 5、9 can effectively inhibit the growth of the cells, so that the bacteria can produce the antibacterial protein in better activity 216. The pH value affects the activity of the bacteriostatic protein just 25、29 in the hyperacid and peralkalic environment, so it is a less feasible method. Keywords: Escherichia coli、induction reaction、fermentation