Improved fermentative production of Monascus pigments in roller bottle culture

The quantities and qualities of Monascus pigments produced by the filamentous fungus Monascus anka in batch submerged, agar surface, and roller bottle cultures were compared. In roller bottles, the fungus became attached to the wall of the culture vessels and produced a larger quantity of both intracellular (1508 absorbance units g^?1 cell mass) and extracellular (27 absorbance units g^?1 cell mass) Monascus red pigments, a yield that was about 10-fold greater than that of batch submerged and agar surface cultures. The optimum time required for maximum pigment production was reduced from 7 days in batch submerged or agar surface cultures to 4 days in roller bottle culture. In the roller bottle culture, the ratio of red to yellow pigments was also greatly increased. The advantage of the rotating vessel might be due to a combination of factors, including better gas exchange, higher medium pH, efficient pigment secretion, solid support for mycelium, and retarded conidiation.