White-Rot Fungi pretreatment of lignocellulosic biomass for anaerobic digestion: Impact of glucose supplementation

Abstract

Anaerobic digestion of lignocellulosic biomass is one of the most efficient ways to produce renewable energy. However, lignin contained in this biomass is difficult to hydrolyse. Pretreatment can help to overcome this limitation. Among them, low-cost fungal pretreatments seem noteworthy. Although widely used in pretreatment for bioethanol production, rot fungi have rarely been applied for improving biogas production during anaerobic digestion of lignocellulosic biomass. The present study investigates the possibility to increase methane production from wheat straw pretreated with several fungal strains. After screening sixty-three strains, twelve preselected strains were used to pretreat straw. Compared to the control straw, up to 43% more methane per gram of pretreated volatile solids were obtained with Polyporus brumalis BRFM 985 strain. Taking into account the dry weight loss measured during pretreatment in non-optimized conditions, up to 21% more methane per gram of initial total solids was observed. Glucose addition during the pretreatment also proved to limit delignification and thus methane production from the substrate.