Chemical modification and immobilization of cellulase for simultaneous pretreatment and saccharification of lignocellulosic biomass in ternary deep eutectic solvent

In this study, chemical modification coupled with immobilization of cellulase was developed for simultaneous pretreatment and saccharification (SPS) of lignocellulosic biomass in ternary deep eutectic solvent (DES). Cellulase was firstly modified with acid anhydrides to form citraconic anhydride modified cellulase (CA-Ce) and phthalic anhydride modified cellulase (PA-Ce), respectively. Then the modified cellulases were immobilized on amino-functionalized mesoporous silica nanoparticles (MSN-NH 2 ) to fabricate CA-Ce@MSN-NH 2 and PA-Ce@MSN-NH 2 . A series of physiochemical characterizations were employed to characterize modified cellulases or immobilization carriers. Thermodynamic analysis and deactivation kinetics in ternary DES (NMMO/Bet/OA) revealed that CA-Ce@MSN-NH 2 had desired thermal stability and solvent tolerance, which maintained 80.5 % initial activity at 70 °C and 77.8 % initial activity in 50 % NMMO/Bet/OA. The SPS of bagasse in NMMO/Bet/OA via CA-Ce@MSN-NH 2 resulted in 84.1 % total reducing sugar (TRS) yield at optimal condition.