Production and Preliminary Characterization of Antioxidant Polysaccharide by Submerged Culture of Culinary and Medicinal Fungi Cordyceps militaris CICC14013

Abstract

Abstract Polysaccharides from Cordyceps militaris show multiple biological activities, such as antioxidation, antitumor, antivirus and immunomodulating properties, etc. The nutritional requirements for antioxidant polysaccharide bio-synthesis by submerged culture of C. militaris were evaluated on the basis of assay for DPPH radical scavenging ability and reducing power in this work. The results showed the best antioxidant activity of polysaccharide could be achieved when the media consisted of mannose, peptone, MgSO4, Na2HPO4, and KH2PO4. Furthermore, the main fraction of antioxidant polysaccharide, CMP-2, was preliminary isolated from the fermentation broth of C. militaris by ethanol precipitation, filtration, and DEAE cellulose-52 chromatography. CMP-2 was composed of mannose, rhamnose, glucose and galactose in a ratio of 2527:164:172:100, and had an average molecular weight (Mw) of approximately 8175 Da. The results suggested antioxidant polysaccharide could be produced by submerged culture of C. militaris and the medium composition significantly affected its DPPH radical scavenging ability and reducing power.