论文部分内容阅读
In order to improve the yield of β-mannase and to investigate the rules of fermentation production, a high-yield β-mannase producing strain, Bacil us licheni-formis HDYM-04, was used to investigate the kinetics models based on the optimal fermentation conditions: HDYM-04 strain was fermented at 37℃ for 30 h with agita-tion speed at 300 r/min and aeration rate at 3 L/min in a 5 L fermenter, the initial addition amount of konjac flour was 2%(w/v), the initial pH of medium was 8.0, and the inoculum concentration was 6.7%(v/v). Three batch fermentation kinetic models were established (cellgrowth kinetic model, substrate consumption kinetic model, product formation kinetic model) bases on Logistic and Luedeking-Piret equations. To be specific, cellgrowth kinetic model was dXdt =0.431X (1-15 X.522 ), substrate consumption kinetic model was -dSdt =1.11 dXdt +0.000 2 dPdt +0.000 8X, and product formation kinetic model was dPdt =133.1 dXdt +222.87X. The correlation coefficients R2 of the three equations were 0.990 21, 0.989 08 and 0.988 12, respectively, which indicated a good correlation between experimental values and models. Therefore, the three equations could be used to describe the processes of cellgrowth, enzyme synthesis and substrate consumption during batch fermentation using B. licheniformis strain HDYM-04. The establishment of batch fermentation kinetic models (cellgrowth kinetic model, substrate depletion kinetic model, product formation kinetic model) could lay the theoretical foundation and provide practical reference for the applica-tion of HDYM-04 in fermentation industry.