大肠杆菌K88菌毛蛋白发酵工艺的初步研究

Preliminary Study on Fermentation Techniques of Escherichia coli K88 Fimbriaeprotein

采用液体培养基包括牛肉膏蛋白胨培养基和强化营养肉汤培养基对大肠杆菌K88进行发酵培养,采用不同摇瓶培养时间和不同pH值的培养基观察发酵结果,研究菌体和菌毛生产量的相关性,并通过紫外分光光度计UV751于600nm处测量菌体OD值以对菌种发酵情况进行检测.热激分离菌体和菌毛蛋白,(NH4)2SO4盐析分离纯化K88菌毛蛋白并用分光光度计于280nm处测定其OD值.透析后经SDSP-AGE检测菌毛蛋白纯度.根据实验结果优化发酵培养条件,确定菌种的最佳发酵工艺,以收获最多的K88菌毛蛋白.经过实验研究,最终确定了大肠杆菌K88在pH值为6.5、转速为250r/min的条件下发酵18个h,菌体和菌毛生产量均达到高峰,同时得出菌毛蛋白和菌体成正相关.

Liquid culture medium including the basic and the nutrition of liquid meat is used to ferment E.coli K88 in this experiment,different hours and various pH are used to look into the result of fermentation,the growth relativity between thalli and fimbriae-protein is studied and the equipment UV751 is used to examine the result by measuring its OD at the place of 600 nm to examine the fermentation condition of the stock culture.Through heat shock K88 fimbriae-protein is isolated from thalli,and salting-out with(NH4)2SO4 purify the K88 fimbriae-protein and determine the protein OD at the place of 280 nm with UV751.After dialysis the purity of K88 fimbriae-protein is examined by SDS-PAGE.The result of the experiment is good to optimize the conditions of the fermentation and confirm the best fermentation techniques of the stock culture,so that the most K88 fimbriae-protein is harvested.Through the experiment the conclusion is obtained that the yeild of thalli and fimbriae-protein is at the top after 18 hours fermentation when pH of culture medium is 6.5 and the rotating speed is 250 r/min,and fimbriae-protein production is positive to thalli growth.