Résumé
Due to the especial properties such as high growth rates, easy extraction as well as high yields, using microorganisms in comparison to other sources is more chosen for pigment production. Pigments are used in food industries as natural colorants and preservatives, they also have pharmaceutical applications. In this study, fungus Monascus purpureus PTCC 5303 have been used to produce red, orange and yellow pigments. At first significant variables were screened based on plackett-Burman design and then the optimized value of two effectivefactors such as yeast extract and K[2] HPO[4] concentrations wasoptimized byresponse surface method. Optimal levels of factors were found to be 2/75 g/L yeast extract and1/5 g/LK[2] PO[4] respectively. Antimicrobial activity of pigments was evaluated on Gram-positive foodborne bacteria under optimal conditionswhich resultsshowed inhibitory effects. Moreover Pigments production at optimal conditions in a bioreactor was evaluatedand the rate of production of red, orange and yellow pigments, 2.05, 1.55 and 0.78 [ODU/ml] were observed respectively