Tuning structural change on lipase for covalently immobilization on S-decorated dendrimer: Efficient and reusable biocatalysts for biodiesel production

Abstract

Two new biocatalysts have been synthesized by immobilizing lipase on the magnetic nanoparticles S-decorated dendrimer, through physisorption (TDMNP@CRL) and S–S covalent bonds (TDMNP@tuned CRL) (CRL: Candida rugosa lipase). The Ugi four-component reaction as a promising strategy was used for tuning lipase and decoration of enzyme with SH to form S–S bonds in TDMNP@tuned CRL. The synthesized biocatalysts illustrated better performance in various ranges of temperature and pH compared to free enzyme and storage stability for 60 days. The excellent stability of the synthesized biocatalyst in different conditions and the presence of magnetic nanoparticles in the structure which provides a very convenient strategy for separation have made it a very distinguished candidate for biodiesel production. The effective factors on biodiesel production including temperature, time, the mole ratio of alcohol to oil, w/w of water to oil, and amount of catalyst were explored and under the optimized conditions, the yield of biodiesel production was 78 % in the presence of TDMNP@tuned CRL which confirmed by 1H NMR spectroscopy. Furthermore, the biocatalyst was easily separated by an external magnet and successfully reused four times without loss of its activity. © 2024 Elsevier Ltd