Process Optimization and Antiviral Activity of High Yielding Prodigiosin from Serratia Marcescens

In order to improve the yield of prodigiosin in the industrial fermentation of Serratia marcescens-S3, the important fermentation condition parameters and key components of the fermentation broth of Serratia marcescens-S3 were optimized, and the inhibitory effect of the extracts of fermentation broth on viral diseases was verified. The results showed that the best medium formulation was: 0.5% of glycerol, 1.5% of peptone, 0.5% of sodium chloride and 0.25% of potassium chloride. The optimal fermentation conditions were: 10% inoculum, 60%-70% loading, constant pH of 6.0, incubation temperature of 28 ℃, stirring speed of 160 r/min, and 60 h fermentation cycle, which not only facilitated the growth of Serratia marcescens-S3, but also maximized the production of prodigiosin. After fermentation under the optimized conditions, the extract solution of prodigiosin was sprayed on Nicotiana benthamiana inoculated with TMV, CMV and PVY, and the amount of TMV, CMV and PVY viruses in leaves was 12.61%, 29.41% and 17.69% of that in the blank control, respectively. The inhibitory effect on viruses was better than that of chitosan oligosaccharide. The fermentation conditions obtained from this study can improve the yield of prodigiosin, and the extracts have significant antiviral property, which has the potential for industrial development and economic application value.