Mathematical modeling of lignocellulolytic enzyme production from three species of white rot fungi by solid-state fermentation

Abstract

This research was conducted by growing three species of white-rot fungi (Coriolus versicolor, Lentinus edodes and Pleurotus ostreatus) on twelve formulations of solid substrates using mixtures of different lignocellulosic materials, calcium carbonate salts and copper sulphate (II). The objective of this study was to propose a mathematical model to describe the biomass growth, lignocellulolytic enzymes biosynthesis, production and consumption of reducing sugars, consumption of cellulose and hemicellulose, and lignin degradation. The three species of fungi grew well on all substrate formulations. The response obtained was evaluated by the titles of all enzymatic activities for several combinations fungus - substrate. C. versicolor had the highest capacity to degrade lignin, cellulose and hemicellulose for all combinations, with 65% as the maximum lignin degradation for F1 combination, and 43% cellulose degradation for F9 combination. The mathematical model proposed for C. versicolor consisted of eleven differential equations to describe the behavior of the cultivation system from the experimental data of all the resulting combinations in order to obtain the largest capacity degradation of lignocellulosic substrates by the fungus. In this work, we present the modeling results for combination F9 fungus - substrate combination, which showed the best behavior related to the degradation of lignocellulosic materials used. The results obtained demonstrated that the model proposed represents a powerful tool to design solid-substrate fermentation processes. © Springer International Publishing Switzerland 2014.