Improved bioconversion of poplar by synergistic treatments with white-rot fungus Trametes velutina D10149 pretreatment and alkaline fractionation

► The subsequence alkaline fractionation further reduced the biomass recalcitrance. ► Biopretreatment showed little effect on the molecular weights of carbohydrates. ► White-rot fungal pretreatment altered the structure of lignin. ► The depolymerization of cellulose occurred at the C1, C4 and C6 groups.