Abstract:This study aimed to optimize the fermentation process for high monacolin K（MK）production by Monascus pilosus engineering strain TI-25.The strain TI-25 was taken as the research object，and the MK yield was taken as the evaluation index.The solid-state fermentation method was used to explore the optimal fermentation process for high MK production by Monascus pilosus engineering strain TI-25 on the basis of a single factor experiment and response surface optimization design.The results showed that the amount of fermented bottled rice，initial water addition，and temperature change time of fermentation would significantly affect the MK yield of fermentation products.The fermentation days，initial pH value of culture medium with seed solution，and inoculation amount of seed solution had little effect on the MK yield of fermentation products；therefore，the response surface optimization design was carried out by selecting three factors: the amount of fermented bottled rice，the initial water addition，and the fermentation days.The optimization results showed that the optimal fermentation conditions for MK production by solid-state fermentation of engineering strain TI-25 were as follows:The amount of fermented bottled rice was 20 g/350 mL；the initial water addition was 32.38 mL；the temperature was changed from 30 ℃for curing of 3 d to 28 ℃for curing of 12 d；the inoculation amount of seed solution was 10%，and the initial pH value of culture medium with seed solution was 4.5.In these conditions，the content of MK in Monascus rice could reach 635.12 mg/kg.