Production Of Pigments And 1-Deoxynojirimycin By Monascus Purpureus

Monascus pigments are azaphilone compounds produced during the metabolic process of M. purpureus FM-4000. The characteristics of the pigments are bright in colour, excellent in heat-resistance and perfect in food safety. With the increasing attention on the issues of food safety, the study of natural pigments have been proven to be important. The study was designed to optimize the liquid fermentation conditions of M. purpureus FM-4000 preserved in laboratory that mainly produced red pigment. The liquid fermentation conditions and the fed-batch fermentation strategies under different p Hs were controlled in the 250 m L shake flask. The optimal conditions were second-order seed at 6 h, inoculation at 10%, fermentation temperature at 33?, and loading volume at 70 m L. What's more, the shear force was proven to play a vital role in process. The feeding strategies were were listed as follows, 20 g/L soybean powder solution at p H=6(±0.1), 0.5 mol/L aqueous ammonia solution at p H=5(±0.1) and 6% rice flour solution at 96 h. Compared to initial colour value, the red pigment colour value was improved by 37.23% after the optimization in shaking flask, which could reach up to 135.67 U/m L. According to the research in shake flask, the fedbatch fermentation in 5 L fermentor was conducted. The optimized parameters for the fermentation were listed as follows, 0~24 h at 300 r/min and 0.5 vvm, 24~84 h at 500 r/min and 0.7 vvm, 84~132 h at 400 r/min and 0.3 vvm. The feeding strategies were listed as follows, 20 g/L soybean powder solution at p H=6(±0.1), 0.5 mol/L aqueous ammonia solution at p H=5(±0.1), 6% rice flour solution in 84 h and 120 h. After 156 h fermentation at 33 ?, 145 U/m L red pigment were produced in 5 L fermenter.Through the combined approaches of LC-MS, pre column derivatization and fluorescence of RP-HPLC, 1-deoxynojirimycin was firstly identified in the solid-state fermentation product of Monascus purpureus SM-005. The yield of 1-deoxynojirimycin reached 27.9 ?g/g. The result suggested new ideas to explore the Monascus metabolic pathway and its regulation but also showed a new way to develop a new ?-glucosidase inhibitor.