Development Of Antibacterial Ppeptide Fermentation Process And Its Large-scale Production Plant Design

At present, the antibacterial peptides (ABPs) industry is at its beginning stage in China. However, the antibacterial peptide used as one of conventional additives is an inevitable trend in the near future. ABPs have very good physico-chemical properties like heat resistance, acidic tolerance, especially, no residual property in animal body when they are digested in intestines. As a green alternative to the antibiotics, this emerging industry of antibacterial peptide has a very broad market application. According to estimates, economically, antibacterial peptide industry can reach a market size of 100 billion RMB by 2020.Bacillus polymyxa, a ABP producer was isolated from root soil of the vine, was investigated to produce antibacterial substances, namely, antibacterial peptides, in this thesis. Firstly, the optimization of fermentation conditions for ABPs production was carried out. In shaking flask culture, its biological titer of 8000 U/ml was reached after 30h incubation. Then the fermentation process was developed in a 5 L fermentor, and scaled up to 5000L tank. the developed fermentation conditions operated in a 5000L reactor were as follows: temperature is 30 degrees, fermentation duration is 48 hours, air flow rate is 1:0.5 VVM. The biological titer of ABPs reached 10000 U/ml. For the development of the down stream process of ABPs, the harvested broth was processed by ceramic membrane micro-filtration using ceramic membrance, followed by concentation by nanofiltration by 2 times. After addion of soluble starch, and then dried using sprayer to get antibacterial peptide raw product.Based on the process developed above, a plant with an annual production amount of 2500 tons of antibacterial peptide was designed.