Production of cordycepin by Cordyceps militaris using submerged liquid culture: Optimization of the culture medium and repeated batch fermentation

Cordycepin (3’-deoxyadenosine) is one of the most versatile metabolites of Cordyceps militaris due to its broad spectrum of biological activity. In this study, response surface methodology (RSM) was applied to optimize the medium components for the cordycepin production by submerged liquid culture. The optimal parameters for cordycepin production within the experimental range of the variables researched was at 30.16 g/L glucose, 10.00 g/L yeast extract, 2.040 g/L KH 2 PO 4 , and 1.460 g/L MgSO 4 . At this condition, the cordycepin was predicted to be 63.69 mg/L. The maximum cordycepin obtained experimentally was 64.15 mg/L, which confirmed the model prediction. The repeated batch operation was proved to be an efficient method to increase the cordycepin yield. During the repeated batch fermentation, the cordycepin yields and productivity of the 2 to 6 cycles are higher than that of 1 cycle.