Enhanced Biocatalytic Activity of Lipase Immobilized on Biodegradable Copolymer of Chitosan and Polyvinyl Alcohol Support for Synthesis of Propionate Ester: Kinetic Approach

The objective of this work was to investigate a kinetic and mechanistic analysis for the synthesis of benzyl propionate which has diverse applications. Furthermore this study illustrates the synthesis and beneficial uses of an ecofriendly support that is made up of chitosan (CHI) and polyvinyl alcohol (PVA) to immobilize lipase Pseudomonas cepacia (PCL), and it showed remarkable enhancement of biocatalytic activity over free lipase. Among various biocatalysts prepared, CHI:PVA:PCL (5:5:2) was found as a robust biocatalyst composition. The lower activation energy (Ea) of immobilized lipase (12.8 ± 0.11 kcal/mol) than that of free lipase (16.6 ± 0.65 kcal/mol) showed better catalytic activity of immobilized lipase. Kinetic parameters were determined which showed that benzyl propionate synthesis catalyzed by immobilized PCL followed the order bi–bi mechanism with benzyl alcohol inhibition. CHI/PVA immobilized lipase biocatalyst showed enhanced (3.5 fold) catalytic activity and efficient recyclability over those of free lipase. Finally, developed protocol was applied for practical biocatalytic applications to synthesize various industrially important propionate esters.