Co-immobilization of lipase from Thermomyces lanuginosus (TLL) and lipase B from Candida antarctica (CALB) on functionalized epoxy resin for enhanced stability, reusability, and biocatalytic efficiency.

Epoxy resin, a durable synthetic polymer with a surface rich in ligand groups, was functionalized with branched polyethyleneimine and activated with glutaraldehyde to serve as a support for the co-immobilization of lipases CALB and TLL. RE/TLL-CALB was characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetry (TGA), and Scanning Electron Microscopy (SEM). The Taguchi L9 method identified the ideal conditions for the co-immobilization of lipases CALB and TLL in the functionalized epoxy resin (RE): 12 h of reaction, pH 9, 100 mM buffer, and an enzyme load of 6 mg/g of support. The biocatalyst RE/TLL-CALB showed a significant increase in immobilization parameters, reflecting greater efficiency in enzyme fixation. Furthermore, it demonstrated superior thermal stability, with a prolonged half-life in the range of 50-80 °C, as well as high resistance to pH variations and the presence of organic solvents. The system maintained its catalytic activity above 80 % even after 180 days of storage, demonstrating that immobilization conferred improved operational stability, extending the biocatalyst's useful life and robustness under adverse conditions.