Submitted to: African Journal of Biotechnology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/15/2012
Publication Date: 3/13/2013
Publication URL: http://handle.nal.usda.gov/10113/57228
Citation: Gang, J., Fang, Y., Wang, Z., Liu, Y. 2013. Fermentation optimization and antioxidant activities of mycelial polysaccharides from Morchella esculenta using soybean residues. African Journal of Biotechnology. 12(11):1239-1249. Interpretive Summary: Edible fungi are used in Chinese medicine and play an important role in enhancing immunity and inhibiting tumor growth. Polysaccharides are important components of the edible fungi; however, polysaccharides from edible fungi have not been commercialized. Therefore, innovative polysaccharide production strategies are needed. This study aims to optimize fermentation conditions for the production of polysaccharides from Morchella esculenta. Fermentation conditions for the fungus Morchella esculenta, were investigated and polysaccharides were produced in large quantities using the improved method. Furthermore, the polysaccharides isolated from the fermentation demonstrated strong biological activities. Information from this study provides improved methods that can be potentially used for commercial production of polysaccharides from fungi and also provides a new route for utilization of soybean residues as substrates.
Technical Abstract: The mycelial polysaccharides from Morchella esculenta are active ingredients in a number of medicines that play important roles in immunity improvement and tumor growth inhibition. So far, the production of polysaccharides from M. esculenta mycelia has not been commercialized. The aims of this work were to screen and optimize the fermentation conditions to produce mycelial polysaccharides from M. esculenta using soybean residues as basic substrates in the composition of the medium, and to evaluate the antioxidant activities of mycelial polysaccharides from M. esculenta. Our results demonstrated that M. esculenta mycelia made good use of soybean residues. The optimal media contained the following components (g/l): soybean residue 22.2, glucose 20.1, KH2PO4 2.0 and MgSO47H2O 1.5. The optimum parameters of liquid culture were identified as the following: initial fermentation pH 7.0, inoculation volume 10%, temperature 28 ºC, and fermentation time 56h. Under these optimized conditions, the values of dry cell weight (DCW) and the production rates of mycelial polysaccharides were 36.22 g/l and 68.23 mg/g, respectively. Furthermore, the mycelial polysaccharides from M. esculenta demonstrated strong antioxidant activities, suggesting their potential therapeutic use as antioxidants. Our study provides insights to the commercial production of mycelial polysaccharides from M. esculenta. Our study also provides a new route for utilization of soybean residues.