Optimization Of Fermentation Process Of Anti-tumor Engineering Bacterium Nissle1917 And Preparation Of Bactera Preparations

In recent years,a lot of probiotics have been developed into health care products,such as Escherichia coli Nissle1917,Escherichia coli CFT073?E.coli CFT073?was used for the treatment of dysentery and protect the intestine.With the further study,bacteria-targeted therapy has become a research hotspot.The characteristics of non pathogenic,so these probiotics can be used as drug carriers,oral administration of drug to treat cancer.E.coli Nissle1917 is a kind of high safety probiotic strains.The engineering strain EcNVY can target transfer protein antitumor drugs azurin,its makes the value of The engineering strain EcNVY greatly improved.The biomass of engineering bacteria is a key factor to guarantee a high expression of azurin.To obtaining antitumor agent production,We need to optimizing the fermentation process.By optimizing the fermentation medium and fermentation conditions,we can get the highly biomass of engineering bacteria.In this study,the fermentation medium of anti-tumor engineering bacterium E.coli Nissle 1917?EcNVY?was optimized by using Central composite design coupled with Response Surface Methodology.By using Placket-Burman design from those culture substrates including Na₂HPO₄,glucose and soybean protein,lactose,sucrose,citric acid,sodium citrate,NaCl,glucose and soybean protein,sodium hydrogen phosphate were found to be the most important factors that affecting biomass of antitumor engineering strain EcNVY.In addition,the primary and secondary relations of factor affecting biomass of EcNVY is that Na₂HPO₄>glucose>soybean protein.Then.by using Central composite design coupled with Response Surface Methodology.the biomass of engineering strain EcNVY will become the numerical expectations.we got the second order differential model of response and variable.We found The R-Squared=95.65%,which shows good fitting.next,we found the optimum fermentation medium for EcNVY production were as follows:pure milk with glucose 23.26 g/L,sodium hydrogen phosphate 8.0 g/L,soybean protein 12.87 g/L,yeast powder 3.00 g/L.The biomass of EcNVY was1.66×10⁹cfu·m L^-1.The fermentation conditions play a great role in the fermentation process.The single factor experiment was conducted on Influence Factors,such as temperature,Initial p H and inoculation.then,Box-Behnken design experiment was carried out for Influence Factors.the biomass of engineering strain EcNVY will become the numerical expectations.we got the second order differential model of response and variable.We found The R-Squared=98.21%,which shows good fitting.next,we found the optimum fermentation condition for EcNVY production were as follows:The fermentation temperature is 36.50?,the initial p H 6.59 and inoculation amount 3.24%.The prediction biomass of EcNVY was 4.31×10⁹cfu·m L^-1.The preservation condition of fermentation preparations has been found.we use the preparations treats the breast cancer of mice,it get a good effect on cancer.In this paper,we studied the fermentation process of engineering probiotic bacteria.We using milk as a medium for engineering bacteria.The engineering bacteria biomass significantly affected factors have been optimized,the fermentation preparations contain a large number of anti-tumor protein.The new oral preparation can be directly used in the treatment of mouse breast cancer and melanoma,To provide a reference for future clinical treatment of cancer and a new probiotic oral preparation for tumor treatment.