Enhanced simultaneous production of mycelia and intracellular polysaccharide in submerged cultivation of Cordyceps jiangxiensis using desirability functions

The effects of medium composition and fermentation parameters on simultaneous production of mycelia and intracellular polysaccharide by medicinal mushroom, Cordyceps jiangxiensis were investigated in shake-flask cultures using desirability functions. The optimal conditions were obtained via the associated desirability as follows: 40 g/l of molasses glycerol, 5 g/l of peanut steep meal, 6 g/l of yeast extract, 1 g/l of KH2PO4, 0.5 g/l of ZnCl2, 0.5 g/l of MgSO4, initial pH at 6, cultivation temperature at 28 °C, 200 ml of medium working volume in a 500 ml flask and 5% (v/v) of inoculum size. Under these conditions, the production titer of mycelia and intracellular polysaccharide reached 24.5 and 8.9 g/l, respectively, after a 9-day submerged cultivation. The use of desirability functions was proved effective in optimizing multi-response fermentation processes and it is readily applicable to other fermentation systems.