Study On The Fermentation, Separation And Antifungal Activity Of Bacterium Prodigiosum Lipopolysaccharides

Bacterium Prodigiosum Lipopolysaccharides (BP-LPS) were macromolecular neutral lipopolysaccharides extracted from cell walls of Serratia marcescens.Its product was white powder,and solubles in water. Bacterium Prodigiosum lipopolysaccharides have the similar biological activity to that of bacterial lipopolysaccharides, and no obvious endotoxic effects. Most of polysaccharide studies showed that it has effects on leukocytes immunity,anti-tumor and anti-inflammatory. In clinical practice, the Bacterium Prodigiosum Lipopolysaccharides were mainly used in adjuvant therapy for leukopenia, hepatitis B, acute and chronic pelvic inflammatory, and has a practical medicinal value. The mianly studies contents and results are as follow:(1) Through the single factor experiment and response surface analysis, the main factors affecting fermentation process of Serratia marcescens NS-17has been tested. The results showed that the optimization medium composition and process condition for the BP-LPS producing were as follow:peptone16g/L, maltose8g/L, KC12g/L, NaCl lg/L, pH7.0, inoculum rate4%, volume of broth50mL (250mL conical flask), shaker speed200rpm, cultured time32h, culture temperature30℃. The optimum cultue dry-cell weight reached4.662g/L, and increased1.73flod than that of the control bacterial culture.(2) The extract efficiency about Bacterium Prodigiosum Lipopolysaccharides in the traditional extraction method and microwave-assisted PW extraction method have been experiement determined. Through the single factor and L9(34) orthogonal experiment proved that the microwave-assisted PW extraction method can effectively improve the extraction rate of BP-LPS. The results showed that the optimization of microwave-assisted PW extraction method in the BP-LPS producing were as follow: Solid-liquid ratio1:30, microwave processing3min, power250W, leaching60minutes. Under above conditions, the BP-LPS extraction amount reached13.413mg/g, and increased1.99flod than that of the traditional methods.(3) The dsorption protein effect of several resins selected were studied, and the best one,was anionic resin D301. The mian factors affecting deproteinizations of the resin D301were analyzed by single factor experiment. The results showed that the optimizal deproteinized conditions were as follows:static processing time2h, crude LPS concentration2mg/ml, solid-liquid ratio1:5. Compared the adsorption effect of D301resin method with the other methods (trichloroacetic acid, hydrochloric acid method, Sevage method), the results showed that the D301resin method was better.(4) The purification effect of Sephadex G-100chromatography column on the BP-LPS were studied. The results analysis experiment by UV spectrometry method and HPLC showed that BP-LPS samples composition were as same as that of BP-LPS product reported, and with high purity. The BP-LPS sample separated could be used for continue research and application.(5) The vitro bacteriostatic activity of the BP-LPS on the trials bacteria were experiement determined. The trials bacteria included:Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Aspergillus niger, Saccharomyces cerevisiae, and Candida albicans. The results showed that the trials bacteria were inhibited by BP-LPS, and the concentration of the BP-LPS was the significant impact factor. About the inhibitory effect of BP-LPS, bacteria was inhibited stronger than that of fungi, and that of mold was the weakest.