Optimization of Culture Conditions on Mycelial Grown in Submerged Culture of Cordyceps militaris

Statistical experimental design strategy (SES) was employed to optimize the culture conditions for the mycelial growth of C. militaris by submerged culture. Using Plackett-Burman design (PBD), liquid volumes in flask and fermentation time were identified as the significant variables that would highly influence mycelial growth, and these variables were subsequently optimized using response surface method (RSM). The steepest ascent method was used to access the optimal region of the culture condition. The results showed that the optimum values of the tested variables were 47.3 mL of liquid volumes in flask and 7.6 days of fermentation time. Under optimized culture conditions, the mycelial production was enhanced from 10.33 to 19.97 g/L. In comparison with that of original culture conditions, 1.9-fold increase was obtained. The validation experiment showed that the experimentally determined production values were in close agreement with the statistically predicted ones.