Effect of Nitrogen Sources on Production and Photostability of Monascus Pigments in Liquid Fermentation

The effect of different nitrogen sources on the yield, distribution and photostability of monascus pigments was detected in liquid fermentation. Compared to the control, glutamic and 6-furturylaminopurine could increase the production of pigments from 4185 to 4303 and 4349 U g−1 for different mechanism. More important, 6-furturylaminopurine could increase the extracellular pigments from 697 to 1404 U g−1. and increased the hue of fermentation broth from 0.887 to 1.072. The light stability of extra and intracellular red pigments could be improved by adding different nitrogen. The half- life of derivatives from Tryptophan and 6-furturylaminopurine increased from 1 h (control) to 4 and 3 h. It was concluded that different nitrogen sources could affected the pigments production, the hue of fermentation liquid, and improved light stability of monascus pigment. It was very usefull for increasing the production and improving the light stability of monascus pigments.