Microbial bioethanol production from Agave tequilana leaves juice sugars: Process variable optimization and kinetic modeling

Abstract

This study focuses on the valorization of Agave tequilana leaves through bioethanol production from juice sugars. Optimal cultivation conditions were determined using a Taguchi orthogonal array design to maximize bioethanol production by Saccharomyces cerevisiae BEL6 61003. The optimal conditions included reducing sugars at 120 g/L, air flow at 0.5 vvm; agitation at 300 rpm, and pH at 4.5. Under these conditions, the maximum bioethanol concentration reached 43.26 ± 2.20 g/L, with a productivity (rP) of 2.4 ± 0.12 g/L·h and a yield of 43 %. A mathematical model was developed to describe the dynamics of the fermentation process under optimal conditions, comparing the kinetic equations of Moser-Boulton and Moser-Loung. The simulations strongly fit the experimental data, with coefficient of determination (R2) values reaching 0.96 for both models. The selection of the best model was assessed using the Akaike Information Criterion (AIC), favoring the Moser-Boulton equation as the more effective model.