Antimicrobial effect of Monascus purpureus red rice against some bacterial and fungal strains

The aim of this study is to evaluate the antimicrobial activity of red yeast rice obtained from a Monascus purpureus mutant strain. There is at present a growing interest in evaluating red rice for use as a natural food dye and/or preservative. The fungus was grown over PDA in tubes at 30 C and the spores suspension was used to inoculate ground steamed rice to produce the red colorant. The antimicrobial effect of Monascus culture, due of monascidin A, confirmed by scientific investigations, was proved against some bacterial and fungal strains. The brut pigment obtained by growing the Monascus strain in surface culture had a antifungal action against some species of Aspergillus, Mucor, Penicillium and Fusarium genus. The yellow pigment isolated from red yeast rice also inhibits bacteria of the genera of Bacillus, Pseudomonas and Escherichia. The observation of bacteriostatic and antifungal effects has lead to the consideration that besides the tinctorial properties, the pigments of Monascus purpureus have a preservative value.