A differential evolution approach to estimate parameters in a temperature-dependent kinetic model for second generation ethanol production under high cell density with Spathaspora passalidarum

Abstract

An unstructured–unsegregated temperature-dependent kinetic model was developed and validated to describe ethanol fermentation in a mixture of xylose and glucose for the nonconventional yeast Spathaspora passalidarum NRRL Y-27907 under high cell density in the temperature range of 26–32 °C. The kinetic model consisted of 13 equations and 16 kinetic parameters, describing cell growth, individual xylose and glucose uptake and product formation. Global parametric estimation was executed through a differential evolution algorithm. Temperature-dependent parameters were identified and adjusted to Arrhenius-type equations as a function of temperature. The overall r2 of the process calibration and validation were 0.972 and 0.959, respectively, indicating that the model satisfactorily described the process in the temperature range investigated. Furthermore, using a 3D projection of the model to simulate ethanol production, it was concluded that temperatures between 30 and 32 °C resulted in the highest productivities.