Optimization of monascus fermentation medium components by response surface methodology

To increase the yield of monascus red pigment, the fermentation medium components were optimized by response surface methodology. By single-factor tests, the basic components of the fermentation medium as following:rice powder, glucose, soybean powder, KH2PO4, NaNO3, MgSO4, ZnSO4, corn syrup were established. By Plackett- Burman experiment, soybean powder, KH2PO4 and NaNO3 were found to be the most important factors to the production of monascus red pigment. Subsequently, the design of steepest ascent experimental was used to approach to the best concentration range of the three key factors. On this basis, Box-Benhnken Design was used to optimize the fermentation medium components, then the optimal fermentation medium components were KH2PO4 1. 52g/L, NaNO3 0. 51g/L, soybean powder 35g/L. In these conditions, monascus red pigment color value was 437. 73U/mL, which was double higher than before.