Co-culture of Rhodotorula mucilaginosa and Monascus purpureus increased the yield of carotenoids and Monascus pigments

In this study, the interaction effect of Monascus purpureus and Rhodotorula mucilaginosa on the growth and metabolism was investigated. R. mucilaginosa was co-cultured with different amount of M. purpureus spores or M. purpureus fermentation filtrate. The co-culture of M. purpureus and R. mucilaginosa with appropriate cell count ratio significantly promoted Monascus pigments yield, but inhibited the growth of M. purpureus. The co-culture of R. mucilaginosa and M. purpureus with 1.25 × 104 spores/mL or 50% (v/v) M. purpureus fermentation filtrate significantly promoted the growth and carotenoids production of R. mucilaginosa. The two co-cultures increased the carotenoids yield by 45.1% and 29.3%, respectively. In addition, the stimulative effect of M. purpureus fermentation filtrate on carotenoids production of R. mucilaginosa might be derived from the synergy of metabolites produced by M. purpureus. In conclusion, R. mucilaginosa co-culture with appropriate amount M. purpureus spores or M. purpureus fermentation filtrate could increase the yield of carotenoids. The co-culture of R. mucilaginosa and M. purpureus was an effective method for increasing the yield of carotenoids and Monascus pigments.