The Biosynthesis And Purification Of Prodigiosin

Prodigiosin, a tripyrrole pigment biosynthesized by Serratia marcescens and some other bacteria, exhibits antimicrobial, immunosuppressive and cytotoxic properties. Recent studies showed that prodigiosin exhibited selective cytotoxicity against cancer cells and induced apoptosis in several cancer cell lines, but was not toxic to healthy cells. Therefore, the studies on the biological mechanisms and pharmacology of the prodigiosins have received wide attentions of researchers.The screening programs were carried out to obtain a mutant by means of physical (UV, Microwave) and chemical (LiCl) mutation. The mutant with high production of prodigiosin was obtained, named YW-1. The production of prodigiosin of this mutant in flasks fermentation was 95±5 mg/L, almost 1.7 times higher than the parent strain.It was found that the production mechanism of prodigiosin of YW-1 was different from the srains which had been reported. The pH of medium increased and finally achieved 8.0-8.5 from 5.0 during the time course of the fermentation, and the optimum pH for prodigiosin production by this stain was between 5.0-7.0. The yield was enhanced and the fermentation time was shortened by optimization of culture media and fermentation conditions in flasks, which lay the foundation foundation for industrial production of prodigiosin.Generally, the prodigiosin produced by S. marcescens was mostly bound to the bacterial cell membrane and only a small part was released to the fermentation broth. Based on this characteristic, extraction of cell and both respectively was applied for separation of prodigiosin. The Silica Gel was uased as a purification method to obtain pure sample. The sample we separated was identified to be prodigiosin by HPLC, UR and IR. By the study of the characters, it was found that the prodigiosin was photosensitive, not temperature-sensitive. It was more stable at solid state than at liquid state.