Improved Catalytic Properties of Thermomyces lanuginosus Lipase Immobilized onto Newly Fabricated Polydopamine-Functionalized Magnetic Fe3O4 Nanoparticles

In this study, magnetic Fe3O4 nanoparticles coated with polydopamine possessing abundant amino groups (Fe3O4@PDA) were conveniently prepared, detailed, and characterized, and then firstly used as a supporting matrix for immobilizing Thermomyces lanuginosus lipase (Fe3O4@PDA@TLL). The effects of some crucial factors on the immobilization efficiency were investigated and the optimal protein loading and activity recovery were found to be 156.4 mg/g and 90.9%, respectively. Characterization studies revealed that Fe3O4@PDA@TLL displayed a broader pH and temperature adaptability as compared to the free TLL, which allows its use at wider ranges of reaction conditions. With regard to the stabilities, the immobilized TLL clearly displayed improved pH, thermal, and solvent tolerance stabilities compared to the free enzyme, suggesting that the biocompatible Fe3O4@PDA might be an outstanding material for immobilizing TLL and acting as alternative support for different enzymes.