Selective Adsorption of Lignin Peroxidase on Lignin for Biocatalytic Conversion of Poplar Wood Biomass to Value-Added Chemicals

Lignin-first biorefineries aim to maximize the valorization of lignin by prioritizing its conversion over other biomass components. This study investigates the selective adsorption of lignin peroxidase (LiP) isozymes from white rot fungi Phanerochaete chrysosporium on lignin, aiming to enhance the biocatalytic conversion of poplar wood biomass into value-added chemicals. The research focuses on the adsorption characteristics of ten recombinant LiP isozymes, particularly PcLiP03, which exhibited the highest adsorption capacity on lignin and negligible adsorption on cellulose. Adsorption isotherms and structural analyses revealed that hydrophobic interactions significantly contribute to the selective adsorption of PcLiP03. Applying PcLiP03 in a continuous stirring cell system effectively converted lignin in unpretreated poplar wood to 2,6-dimethoxy-1,4-benzoquinone under ambient and mild conditions, highlighting its potential for selective lignin depolymerization in integrated biorefineries. This work underscores the importance of enzyme–substrate interactions and offers a promising approach for more efficient and sustainable biomass utilization.