RII Track-4: Elucidating Enzyme-Ionic Liquid Interactions to Enable Effective Lignin Valorization

Lignin is one of the three main building blocks of lignocellulosic biomass and the second most abundant terrestrial biopolymer. Despite its great potential to a wide range of chemicals, lignin is yet an underutilized substrate under the current bio-refinery concept. The successful conversion of lignin to high value-added chemicals brings in economic viability and success of a bio-refinery, and thus enabling cost-competitive biofuel/chemical production. Two key problems are to improve the contact of the bulky poorly soluble lignin polymer to the catalyst and the selective/controlled breakdown of inter-unit linkages. The PI’s lab has developed a novel biocatalytic process to upgrade biomass-derived lignin into aromatic reactive intermediates in aqueous phase ionic liquid (IL). By designing new interfaces for biocatalyst and solvent systems, the interactions of the catalyst with lignin can be optimized to enhance selective depolymerization and enable economical production of renewable aromatic chemicals. However, our preliminary results do not provide enough explanation for these effects at a molecular level. Elucidating the interactions of enzyme with IL will allow a more rational approach to synthesize better ILs and the ability to reengineer better enzymes to optimize their activity in aqueous IL solution.