Biocatalytic transformation of Ganoderma lucidum by porcine pancreatic lipase in hydrophobic deep eutectic solvents.

Enzyme applications in industry are often limited by low stability, poor reusability and challenging recovery. This study presents a sustainable strategy for enhancing enzyme performance by immobilizing porcine pancreatic lipase (PPL) onto Ganoderma lucidum using a hydrophobic deep eutectic solvent (HDES) as a reaction medium to facilitate enzyme immobilization. Among several HDESs tested, menthol:decanoic acid (HDES 1) showed the highest lipase activity (198.38%) and was selected for immobilization. Under optimized conditions (3 h, 40 °C, pH 7.0), the immobilized PPL achieved 212.41% catalytic efficiency, a 13 day half-life and retained activity over two reuse cycles. FTIR analysis revealed a shift in the secondary amide band from 3312 to 3306 cm-1, indicating modifications in protein hydrogen bonding. BET and EDX analyses confirmed enzyme adsorption and successful loading, while GC-MS identified fatty acid derivatives, demonstrating effective catalysis. Notably, HDES 1 enabled the immobilized enzyme to replace hexane in esterification reactions, achieving ∼90% fatty acid conversion surpassing the free enzyme. Molecular docking further highlighted strong interactions between HDES 1 and PPL's catalytic residues, validating its stabilizing role. Overall, the G. lucidum-HDES 1 platform provides a green, efficient and versatile biocatalytic system with significant potential for bioenergy production and sustainable applications in the oil industry.