Liquid-state fermentation conditions for monascus pigments production by Monascus purpureus JR

In this paper,the liquid-state fermentation conditions were optimized to improve monascus pigments production by Monascus purpureus JR.Firstly,the effects of different process parameters such as medium volume,inoculum volume and initial pH on monascus pigment content were investigated,respectively,and the results revealed that a medium volume of 30 mL/250 ml shake-flask,an inoculum volume of 5-20 % and an initial pH of 7.0 were the optimal fermentation conditions for M.purpureus JR;Furthermore,the modes of shake-flask fed-batch cultivation and batch cultivation were compared.As a result,the final dry cell weight and monascus pigment content under shake-flask fed-batch cultivation reached to 44.57 g/L and 350.76 U/mL,respectively,which were significantly higher than that obtained under shake-flask batch cultivation(25.59 g/L and 160.83 U/mL).