Physiological Active Substance Changes of Soybean Curd Residue Fermented by Preussia aemulans and its Bioactivity

A new species of fungus Preussia aemulans isolated from the Cordyceps sinensis fruiting body was cultured by soybean curd residue using solid-state fermentation method. The content of polysaccharide, amino acid, protein, phenolics and nucleoside were massively improved under the optimum conditions, including 10% adding dosage of glucose, 3% adding dosage of beef extract, 15 days of fermentation time. The crude Polysaccharide (CPS) fraction indicated significant immunomodulatory activity on macrophage RAW 264.7 cells and the Ethyl Acetate Extract (EAE) fraction revealed the moderate anti-proliferation ability on human colon cancer cell DLD-1 at high concentration. Both of CPS and EAE showed excellent antioxidant activities properties. The results were demonstrated that the fermented Soybean Curd Residue (SCR) could be utilized as nontoxic, safe and functional food, food additive and feed.