Recyclable biocatalytic composites of lipase-linked magnetic macro-/nano-particles for glycerol carbonate synthesis Original Research Article

Lipase immobilized biocatalysts were prepared via enzyme binding onto functionalized surface of magnetic micro-/nano-particles. In order to achieve an efficient biocatalytic composite the immobilization parameters (e.g. lipase concentration, pH of the immobilization phase, activation reagent) were correlated with support morphology and type of the functional group on the support surface. The characterization of the lipase-particle composites was made using FTIR and UV–Vis techniques. The biocatalyst activity was evaluated in the transesterification reaction of glycerol with DMC (dimethyl carbonate). Under solvent-free conditions the conversion of glycerol was of 48.6% with the selectivity in glycerol carbonate (GlyC) of 85%. The biocatalyst composites were easily recycled using the magnetic properties of the support. Compared to free enzyme, recycling experiments demonstrated that the operational stability of the heterogeneous biocatalyst was improved (fifteen cycles for bio-composites vs. four cycles for free enzyme).