Fungal Pretreatment of Albizia Chips for Enhanced Biogas Production by Solid-State Anaerobic Digestion

Albizia biomass is a forestry waste that has recently been studied for biogas production by solid-state anaerobic digestion (SS-AD). However, albizia chips showed low methane yields because of their recalcitrant structure. In this study, albizia chips were pretreated by Ceriporiopsis subvermispora, a white-rot fungus, for enhanced biogas production by SS-AD. After 48 days of fungal pretreatment, degradation of lignin in albizia chips was found to be around 24%, which was about 2 times that of cellulose and hemicellulose. Fungal pretreatment of albizia chips resulted in more than 4-fold increases in glucose and xylose yields during 72 h of enzymatic hydrolysis and a 3.7-fold increase in the cumulative methane yield during 58 days of SS-AD. Degradation of volatile solids, cellulose, and hemicellulose in pretreated albizia chips was more than 4 times as high as that in raw albizia chips during SS-AD. These experimental results indicated that fungal pretreatment of albizia chips with C. subvermispora is a highly effective strategy to improve the methane yield from this tropical wood waste via SS-AD.