Kinetic modeling of pentose fermentation: understanding the synergistic behavior of inhibitors in the yeast metabolism of genetically modified S. cerevisiae

• Grant number: 19/00103-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): April 01, 2019
• Status: Discontinued
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Edvaldo Rodrigo de Morais
• Grantee: Rafael Boni
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovações (Brasil). Campinas , SP, Brazil
• Associated scholarship(s): 22/08001-5 - A hybrid model approach to estimate and predict the behaviour of the lignocellulosic fermentation process facing the synergistic effect of inhibitory compounds and mixed carbon sources, BE.EP.DD

Abstract

In Brazil, the main lignocellulosic materials for the production of second-generation ethanol are bagasse and sugarcane straw. In general, lignocellulosic biomasses, basically composed of cellulose, hemicellulose and lignin, present a complex and compact structure, which requires a pretreatment step (physical and/or chemical), whose main objective is to recover, through the solubilization of the hemicellulosic fraction, the sugars of five carbon or pentoses, and increase the surface area of the biomass, to a greater yield of the enzymatic hydrolysis. However, inhibitory compounds generated during the pretreatment promotes the reduction of yield in the fermentation process. In addition, sugars of five carbons such as xylose are not natively fermented by S. cerevisiae, although they are able to metabolize xylulose, an isomer of xylose. Therefore, the objective of this project is to perform a mathematical and kinetic modeling of the fermentation process of pentose using S. cerevisiae G.M.O. containing the enzyme xylose isomerase to evaluate and understand the influence of synergistic profiles of inhibitors in the production of second-generation ethanol. Experimentally is expected to identify the concentrations of the inhibitors, separately and in combination, which affect the fermentation of pentose, while computationally is expected to have a model that adequately represents the reaction mechanism and the different types of inhibition. (AU)