P72: Effects of pH and temperature shift on production of monacolin K in Monascus fermentation

Monascus-fermented rice is a traditional oriental food and has been used as a natural food dietary supplement because of its bioactive compound such as monacolin K, indicated for reducing serum cholesterol level. Production of monacolin K depends on the type of Monascus strain and cultivation conditions. In this study, Monasus ruber KCCM 60394 was used to investigate effects of pH and temperature shift on production of monacolin K. Production process for Monascus-fermented rice consists of 3 steps including a plate culture, liquid culture for seed and solid-state fermentation in rice as final step. Monascus strain was cultivated at variable pH condition such as 5, 6, 7, 8, 9 for 5 days at liquid cultivation step, and then the content of monacolin K was detected after solid state fermentation in rice. Monacolin K content of finally fermented rice was highest at pH 7 in liquid culture state. To study effects of temperature, the strain was cultivated at 25°C and 30°C, at every steps, respectively. The shift of cultivation temperature also enhanced the production of monacolin K. The content of Monacolin K (560ppm) from Monasus strain at the condition of 30°C for liquid cultivation and then 25°C for solid-state fermentation was higher than that (418ppm) at the constant temperature of 25°C or 30°C both for liquid cultivation and solid state fermentation. This result suggests that pH and temperature at liquid cultivation have an influence on monacolin K production and solid state fermentation of Monascus at the next step.