| 【Objective】Monascus produces a variety of enzyme substances in the process of growth and metabolism. The study is aimed to optimize the production process of digestive enzymes fermented by Monascus.【Method】The activities of liquefaction enzymes, glucoamylases and proteases in 7 strains of Monascus solid-state fermentation products were studied, and the strain Monascus purpureus ZH6 with high enzyme activities was screened. The effects of fermentation time, substrate water addition, inoculation amount and culture temperature on the activities of glucoamylase, liquefaction enzyme and protease produced by solid-state fermentation of Monascus purpureus ZH6 were explored. On the basis of single factor experiment, response surface optimization was carried out with water addition, inoculation amount and culture temperature as independent variables, and the activities of glucoamylase, liquefaction enzyme and protease in solid-state fermentation products of Monascus purpureus ZH6 as dependent variables.【Result】The production process was optimized by response surface methodology. When the culture time of solid-state fermentation of Monascus purpureus ZH6 was 6 days with the conditions of water addition 42 mL, inoculation amount 20% and the culture temperature 33 ℃ , the liquefaction enzyme activity reached 119.27 U/g; When the fermentation culture time was 10 days with the conditions of water addition 38 mL, inoculation amount 20% and the culture temperature 30 ℃ , the glucoamylase activity reached 614.32 U/g; When the fermentation culture time was 7 days with the conditions of water addition 35 mL, inoculation amount 20% and the culture temperature 31 ℃ , the protease activity reached 1 194.21 U/g.【Conclusion】The production process optimized by response surface methodology could improve the digestive enzyme production capacity of Monascus purpureus ZH6 effectively. |
