Natural Pigment Production by Monascus purpureus: Bioreactor Yield Improvement through Statistical Analysis

Among the ways of pigment production, microbial synthesis has gained more interest for high growth rate, easy extraction and high yield. Pigments are used in the food industry as natural colorants and preservatives; they also have pharmaceutical applications. In this study, fungus Monascus purpureus PTCC 5303 was used to produce red, orange and yellow pigments. At first, significant variables were screened based on Plackett-Burman’s design. The optimized value of two effective factors, i.e. concentration of yeast extract and K2HPO4 by three-level, was more studied by the response surface method (RSM). The most suitable level was 2.75 g/L for yeast extract and 1.5 g/L for K2HPO4. Antimicrobial activity of the pigments was shown on Gram-positive food-borne bacteria under optimal conditions. Moreover, pigment production at optimal conditions in a bioreactor was evaluated, and the rate of production of red, orange and yellow pigments was obtained to be 2.05, 1.55 and 0.78 (ODU/ml), respectively.