Production of lignocellulolytic enzymes from three white-rot fungi by solid-state fermentation and mathematical modeling

Abstract

Three species of white rot-fungi (Pleurotus ostreatus, Coriolus versicolor, and Lentinula edodes) were grown on 12 solid media based on several  lignocellulosic materials (oak sawdust, coconut husks, coffee husks and corn bran) during 49 days. The media had varied carbon/nitrogen ratios and CuSO4 content. The objective of the work was to evaluate the effect of the media formulation on the production of lignocellulolytic enzymes and degradation of lignocellulosic components by the three fungal species. C. versicolor exhibited the highest ability to degrade the three main polymers of the lignocellulosic waste materials employed and to produce ligninases with titers as high as 107 U/g solid substrate in the case of laccase. In addition, a mathematical model describing the fermentation kinetics of the cell biomass growth, degradation of lignocellulosic components, and lignocellulolytic enzyme production for the fungal species/medium combination exhibiting the best performance under solid-state   fermentation conditions was proposed and validated in the case of C. versicolor. The mathematical model could be used to provide valuable information on the process itself as well as to contribute to the  development of a future commercial process for lignocellulolytic enzyme production.
 
Key words: White-rot fungi, cellulases, ligninases, degradation of lignocellulosic materials, fermentation kinetics.