||In this study, the optimized medium composition for polysaccharide production in submerged cultures of M. esculenta BCRC 36348 were investigated. When using 2% glucose as carbon source, maximal mycelium dry weight, formation of intracellular polysaccharide and total polysaccharide were obtained. Yeast extract is the optimal nitrogen source. When 0.5% yeast extract were added, maximal production and yield of total polysaccharide were found. Although addition of plant oils inhibit the growth of M. esculenta BCRC 36348, production, content and yield of total polysaccharide significantly increased. Addition of 1% corn oil to the medium gave the best effect. After cultivation for 6 d, the maximum production and content of total polysaccharide, i.e. 2.18 g/L and 335.64 mg/g DW, respectively, by M. esculenta BCRC 36348 were found in the medium containing 2 % glucose, 0.5 % yeast extract, 1 % corn oil, 0.0068 % KH2PO4 and 10 % mineral solution.
With response surface methodology, maximal production of intracellular polysaccharide (1.97 g/L) was obtained by M. esculenta BCRC 36348 after 6 d of cultivation when the medium contained 3.31 % glucose, 0.39 % yeast extract, 1 % corn oil, 0.0068 % KH2PO4 and 10 % mineral solution. While maximal production of total polysaccharide (2.22 g/L) was found when medium contained 3.34 % glucose, 0.41 % yeast extract, 1 % corn oil, 0.0068 % KH2PO4 and 10 % mineral solution.