Monascus purpureus : A potential source for natural pigment production

Abstract

In this study, growth pattern, temperature & pH on pigment production and mycelial growth of Monascus purpureus was investigated in submerged culture. It has been observed that maximum red pigment was produced at the 16th day of incubation (11 CVU/ml at 510 nm). The favourable temperature for microbial growth and pigment production was found to be 30°C among the experimented temperatures. Also, the maximum pigment was observed at a pH value of 5.5. Effect of different solid substrate on pigment production and optimised by variable Carbon and Nitrogen content has also been investigated. Local unpolished rice (11.5 CVU/ml) was found to be the best source as a solid substrate and there was no impact on pigment production when the substrates were supplemented with glucose. For variable nitrogen sources, a positive increase in pigment yield was observed. Maximum pigment yield was observed with rice supplemented with 5% yeast extract (29.9 CVU/gds) followed by 1% yeast extract (25 CVU/gds) and for 5% MSG (25.2 CVU/gds) followed by 1% MSG (18.1 CVU/gds). There was no considerable impact of peptone-supplemented substrates on pigment production. The presence of citrinin was examined by LC-MS. Key words: Monascus, pigment, mycelial growth, submerged culture, citrinin.