Maltose syrup residue as the substrate for Monascus pigments production

The objective of this study was to determine the effect of pH on the growth rate and production of pigments by Monascus ruber from maltose syrup residue as a substrate. The cultivations were carried out in solid and submerged media under different pH conditions. The highest radial growth rate occurred when the Monascus ruber was cultivated at pH 6.5 and the production of yellow pigments occurred at low pH values (2.0 and 2.5), whereas the production of orange pigments occurred at pH 3.0 and 3.5 and that of red pigments when the fungus was cultivated above pH 4.0. The results showed that the pH value had a significant influence on the radial growth rate and production of pigments, and especially on the profile of yellow, orange and red pigments when cultivated in a medium containing maltose syrup. Maltose syrup was shown to be a potential substrate for the production of pigments by Monascus ruber, potentiating the use of byproducts from the syrup processing industry to produce microbial pigments.