Establishment And Verification Of The Kinetic Models For The Solid State Fermentation By Compound Yeasts

In this study, we have studied the dynamic changes of fermentated material dry weight, β-glucan, mannan and total sugar content during the solid-state fermentation of the compound yeast through recording and determining some parameters, such as the change of the number of living bacteria, temperature and the value of pH of solid state fermentation material and the yield of the production in the industry production, then using the Logistic equation,Luedeking-Piret equation and Luedeking-Piret/like equation to describe the process of the solid state fermentation by compound yeasts. The kinetics of the biomass growth kinetic, the kinetics of the product generation and the kinetics of substrate consumption were nonlinear fitted by the mathematics software of Origin 8.0 and 1stOpt15PRO. Then we obtained the biomass growth kinetic model,β-glucan generation kinetic model, mannan generation kinetic model, and substrate consumption model kinetic, and they were B=16.99/[1+(16.99/4-1)e-0.17941], P=80.79+4.09{16.99/[1+3.2477e-0.1794]-4}, P=47.73+1.27{16.99/[1+3.2477e-0.1794t]-4},and St=128.12-8.93{16.99/[1+3.2477e-0.1794t]-4} respectively. The R2 of the four models were 0.9598,0.9130,0.9065 and 0.9496 respectively, and the equations were highly significant (P<0.000\).Under the same fermentation condition, we conducted the experiment three times to verify the accuracy of the models, and analyzed the result of fitting degree and standardized residuals. The results indicated that our established dynamics models of the solid-state fermentation of the compound yeast could have very good illustration on the yeast growth, product generation and substrate consumption in the process of the solid state fermentation process. Moreover, our established dynamic models can also provide the scientific foundation for the prediction of product generation and optimization of the fermentation process.