Optimization of Solid-state Fermentation of Rice by Cordyceps militaris by Response Surface Methodology

Plackett-Burman design was applied to screen 3 significant ones(material/water ratio, light intensity and illumination time) from 5 potential key factors influencing the solid-state fermentation of rice by Cordyceps militaris. After the maximum response region was approached by steepest ascent path design, the significant factors were optimized by central composite design combined with response surface methodology. A material/water ratio of 5.19:1(m/V), temperature of 25 ℃, inoculum size of 12 mL/100 g, light intensity of 980.13 lx and an illumination time of 9.19 d were found to the optimum conditions to obtain a cordycepin yield of 64.1 mg/100 g.