Effect of pH on citrinin and red pigments production by Monascus purpureus CCT3802

Abstract

The production of red pigments and citrinin by Monascus purpureus CCT3802 was investigated in submerged batch cultures performed in two phases: in the first phase, cells were grown on glucose, at pH 4.5, 5.5 or 6.5; after glucose depletion, pH was adjusted, when necessary, to 4.5, 5.5, 6.5, 7.0, 8.0 or 8.5, for a production phase. The highest total red pigments absorbance of 11.3 U was 16 times greater than the lowest absorbance and was achieved with growth at pH 5.5, followed by production at pH 8.5, which causes an immediate reduction of the intra cellular red pigments from 75% to 17% of the total absorbance. The lowest citrinin concentration, 5.5 mg L -1 , was verified in the same culture while the highest concentration, 55 mg L -1 , was verified in cultures entirely carried out at pH 5.5. An alkaline medium, besides promoting intra cellular red pigments excretion, strongly represses citrinin synthesis.

Red pigment production by Penicillium purpurogenum GH2 is influenced by pH and temperature

“…Chen and Johns (1993) in a study of a Monascus purpureus culture demonstrated the presence of yellow pigments (ankaflavin) at a low pH (4.0) and red pigments (monascorubramine) at higher pH (6.0), contrary to the results obtained in our research. Other authors (Lin and Demain, 1991;Orozco and Kilikian, 2008) found a positive effect on cellular growth due to the pH of the culture medium, favoring the production of red pigments intracellularly and extracellularly (secondary metabolites) at a pH of 5.5, as shown in our study. These results suggest that pH can affect the activities of enzymes involved in the biosynthesis of pigments, but the effect depends on the particular microorganism utilized.…”

Optimization of Monascus Pigment Production and its Antibacterial Activity

“…3a. An increase in extracellular absorbance for red pigment was found at alkaline pH (Orozco and Kilikian, 2008). Maximum biomass production was noticed at pH 4.0.…”

Monascus pigment production in bioreactor using a co-product of biodiesel as substrate

“…growth. Orozco and Kilikian (2008) also studied the production of biomass and pigments and obtained the kinetic parameters in a 4 L bioreactor. They obtained 5.2 to 10.4 g.L -1 of biomass and 11.3 UA of red pigments using Monascus purpureus and glucose as a substrate.…”