One-Pot Method of a Recyclable Lipase-Nanocatalyst Based on Chitosan for Ethyl Levulinate Synthesis

Abstract

As a natural basic polysaccharide, chitosan has been widely used for the immobilization of enzymes. In this study, chitosan magnetic nanoparticles were successfully prepared and characterized. Lipase was immobilized by electrostatic interactions and covalent crosslinking via a one-pot method, and the optimal conditions were explored. The hydrated particle size of the lipase-nanocatalyst was 189.12 nm. The properties of the lipase-nanocatalyst were studied in detail. Compared with free lipase, the catalytic activity was increased by 2.78 times, and it had broadened pH, thermal, organic solvents and storage. It showed good repeatability; the residual activity was approximately 92.26% after the 10 th recycle, and the cumulative catalytic activity was 13.42 times that of free lipase. Finally, lipase-nanocatalyst was used to synthesize ethyl levulinate, with a production ratio of 68.6%. Thus, our findings provide a foundation for lipase-nanocatalyst showing several attractive features, such as easy preparation, excellent catalytic activity, good stability and reusability.

Keywords: Magnetic nanoparticles, Chitosan, Lipase nanocatalyst, One-pot method, Ethyl levulinate