Studies On Liquid Fermentation, Extraction & Purification And Sulfation Modification Of Ganoderma Lucidum Polysaccharides

The biological activity of Ganoderma lucidum polysaccharide and the immunological mechanism of its anti-tumor activity, immunomodulating effect were summarized, the effects of the major factors in submerged fermentation of Ganoderma lucidum were discussed, the relationships between structure and effect of polysaccharide were studied, meanwhile, some motheds of molecular modification were listed.A height mycelia yield strain was screened out from 11 tested strains of Ganoderma lucidum, as Ganoderma lucidum-07(GL-07). The results of orthogonal test showed that, the optimum formula of liquid fermentation medium of GL-07 was glucose 4%, yeast extract 0.3%, KH2PO4 0.15%, MgSO4 0.1%. The optimum fermentation conditions were as follow:initial pH,4.0; medium volume,40%; inoculation volume,10%; culture time,8d. The results of 100L fermentation tank pilot study showed that, mycelia yield was 11.26g/L, extracellular polysaccharide yield was 1.632g/L.The optimal extraction condition of water-soluble polysaccharides from Ganoderma lucidum mycelia was determined by single factor method and response surface analysis, listed below:extraction temperature,100℃; extraction time,2.45h; ratio of water to raw material,45.72:1; with one-time extraction. Under these conditions, the relative error between the actual extraction rate 2.228% and the model theory predicted rate was less than 2%.The best enzyme for deproteinization of Ganoderma lucidum polysaccharide was papain, the best way was that enzymatic hydrolyzed by papain, and then treated by Sevage method for 3 times, the removal percentage of protein reached 76.3%. The ultraviolet spectrum of deproteinized polysaccharide showed that there wasn't protein or nucleic acid because no absorption peaks at 260nm and 280nm.Treated by ultrafiltration, extracellular polysaccharide of Ganoderma lucidum (GLP) exhibited a single polysaccharide peak on HPLC chromatogram, the weight-average molecular weight of GLP was 146948Da, the content of polysaccharide reached 98.68%. The 13C-NMR spectrum confirmed GLP was consisted of three kinds of different monosaccharide residues, as a heteropolysaccharide, and there wereα,βpyranose configuration and 1→3,1→6 glycosidic linkage.GLP was sulfated by the means of using chlorosulfonic acid-pyridine. The infrared spectrum showd GLP was combined with sulfate, and the sulfated product yield was 35.6%.