| This paper studied to produce biotechnology of the Schizophyllan which has a certain functional activity by the model of solid fermentation,using by-products during the processing of fiber-rich diet (corn bran, wheat bran, rice bran) as the raw material,and using the medicinal fungus-Schizophyllum from white-rot fungi group as the biological starter culture. The research involved the optimization of solid fermentation cultural condition of Schizophyllum,the optimization of extraction technology of Schizophyllan and the study of the Schizophyllan's purification and its property and function.Four typical Schizophyllums were determined as the experimental strains on the basis of the preliminary screen. The result showed that: in the four Schizophyllums, the highest rate of extracellular polysaccharides was A, the yield was 0.072 g / g (substrate dry basis). Considering the yield of exopolysaccharide,the source and price of raw materials, corn bran was chosen as fermentation medium, the suitable condition of solid fermentation :fermental temperature 27℃,humidity 60%,fermental time 7days. Though the single factor experiment and twice rotation orthogonal test, we got the best extraction process: extraction temperature90℃,time 60 minutes,ratio of dosage liquor 1:30, the final yield of exopolysaccharide was 0.048 g/g (substrate dry basis).The monosaccharide composition and structure analysis showed that the main component of the Schizophyllan was glucan,and its content was total sugar's 80.92%. The Schizophyllan was a water-soluble polysaccharide with high degree of polymeri- zation, and its average relative molecular weight was about 2.3 million. The Schizophyllan polysaccharide solution had characteristic of hyperviscosity, its viscosity was highly affected by the temperature and concentration and lowly affected by the pH value. The Schizophyllan polysaccharide also had a strong emulsive capacity and emulsion stability,the index obviously surpassed common edible gum -xanthan gum. Besides,it also had a good liquid-binding power and oil-binding power.In vitro-cell experiments showed that the Schizophyllan could obviously inhibit the human lung cancer cells A549, hepatoma carcinoma cell HepG2 , chronic myelogenous leukemia cell K562. When dose of polysaccharides was 1mg/mL,its inhibition ratio was 33.5%, 59.4%,73.7%. |
