Study on the liquid fermentation conditions of glucoamylase by Monascus purpureus

The production conditions of glucoamylase through liquid-state fermentation by Monascus purpureus G6 were optimized.Based on results of single factor tests, the optimal conditions for glucoamylase production were 8% rice powder, 1%peptone, 0.1% KCl, 0.01% ZnSO₄, 0.005% Fe SO4, 0.015% MnSO₄, 50 m L/250 m L loading medium volume ( v/v) , 12%inoculation amount ( v/v) and rotation speed of shaking incubator was 150 r/min, initial p H value of culture medium was 4.0, fermentation temperature was 32 ℃.The fermentation was carried out under these conditions for 10 days to obtain the maximum glucoamylase activity of 1652.36 U/m L, which was 14.08 times higher than that without optimization of fermentation condition.