Kinetic modeling of ethanol production by Scheffersomyces stipitis from xylose.
This work focuses on the kinetics of ethanol production by Scheffersomyces stipitis on xylose with the development of a mathematical model considering the effect of substrate and product concentrations on growth rate. Experiments were carried out in batch and continuous modes, with substrate concentration varying from 7.2 to 145 g L(-1). Inhibitory effects on cell growth, substrate uptake, and ethanol production rates were found to be considerable. Kinetic parameters were obtained through linear and non-linear regression methods. Experiments in continuous mode were performed at different dilution rates to evaluate the inhibitory effect of ethanol. A mixed mathematical model which combined Andrews and Levenspiel's models, combining substrate and product inhibition, was used. A quasi-Newton routine was applied to obtain a more accurate fitting of kinetic parameters. The parameters such as cell to product factor (YP/X) and limiting cell yield (YX) were shown to be dependent on substrate concentration. The kinetic model fitted satisfactorily the experimental data.
Daniele
D
Farias
Rafael
R
R de Andrade
Francisco
F
Maugeri-Filho
D001709:Biotechnology; D005285:Fermentation; D007700:Kinetics; D008954:Models, Biological; D010843:Pichia / Q000254:growth & development / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism*
D014994:Xylose