Study On Efficient Separating And Preparating Prodigiosin From Serratia Marcescens

Prodigiosin(PG) is a red pigment and the secondary metabolites of Serratia marcescens, which contains three conjugated pyrrole rings. Because of its high specific for cancer cells and low toxic to normal cells, PG is expected to become a kind of potential anticancer drugs.The purpose of this research is to obtain the prodigiosin products of high purity.Experiments were divided into three sections. First, isolate and purify a kind of stain, and identify it as serratia marcescens. Secondly, optimize the culture medium and its fermentation condition in which serratia marcescens ferments and produces red pigment to raise its productivity. Thirdly, seperate the metabolic product the red pigment, from fermentation broth. After purification, check its purity and identify it as prodigiosin.1) A red pigment-producting strain was isolated from the acidic soil of the saccharification workshop in the Xinghua biochemistry Ltd. in Huangshi, Hubei province. Observe its growth morphology and colony characteristics, and the physiological-biochemical properties were studied. Then the strain was identified as Serratia marcescens, and was named Serratia marcescens ZSG, which was maintained in China Center for Type Culture Collection(CCTCC NO: M209195).2) In order to improve the production of prodigiosin, use characteristic absorption peak of PG at wave length in 534nm(A534) and the dry weight of serratia marcescens strain as detection indexes to figure out the effects of medium components and fermentation conditions of serratia marcescens. Select sucrose, peptone, inorganic salt MgCl2 as factors to design single factor experiments, and finally be concerned that the best medium components where serratia marcescens can get high production of prodigiosin are sucrose(1.0%), peptone(1.5%) and MgCl2(0.25%). A534 was 0.120 and production was 10.44mg/L of PG before optimization, A534 was 1.007 and production was 96.53mg/L of PG after optimization.3) Preliminary extraction of prodigiosin: prodigiosin was extracted fromfermentation broth, then measured value in A534 was 0.030; the cells were dissolved in methanol, then ultrasonic method was used to break pollen wall, then measured value of supernatant in A534 was 0.989. The content of PG in cells is much higher than that in fermentation broth, confirming PG is the intracellular product.4) Purification of PG: PG purification by the thin layer chromatography, then purification again by silica gel column chromatography. In the end, the purity of products was 98% by HPLC, and was identified to be prodigiosin by UR, IR and LC-MS.