What is the difference between the fermentation of genetically engineered bacteria and traditional microbial fermentation?

The fermentation process of bioengineered bacteria constructed by gene recombination technology is different from the traditional fermentation process. As far as biomaterials are concerned, the former contains recombinant vectors with foreign genes. The latter is a single microbial cell; Considering the fermentation process, the purpose of fermentation production of bioengineered bacteria is to obtain a large number of exogenous gene products and reduce the protein pollution of host cells as much as possible. The high-level expression of foreign genes is not only related to the relationship between host, vector and cloned gene, but also closely related to its environmental conditions, so it is far from enough to produce biological products only by traditional fermentation technology.

The factors affecting the expression of foreign genes were analyzed, and a set of fermentation technology suitable for the efficient expression of foreign genes was explored.

The two most important problems in the fermentation of genetically engineered bacteria are the high-density fermentation of bacteria and the determination of induction conditions. The high-density growth of bacteria will lead to insufficient oxygen supply, and a large amount of acetic acid will be produced in the culture medium, which will greatly affect the growth of bacteria, which is worthy of attention; In addition, there is no direct correlation between the density of bacteria and the expression of foreign proteins, and the combination of them is the determination of induction conditions. In addition, the metabolic pathways of engineering bacteria may be different under different fermentation conditions, which will have different effects on the downstream purification process of the target protein.