| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 34310 | Process Biochemistry | 2015 | 13 Pages |
•Synthesis and characterization of biocompatible immobilized biocatalyst.•4-folds higher catalytic activity of immobilized lipase compared to free in SC-CO2.•Optimized synthesis of citronellyl laurate in SC-CO2, provided 94% yield in 3.5 h.•Protocol extended to synthesize industrially important 12 laurate esters (99–93% yield).•Biocatalyst showed better activity–stability in SC-CO2 media upto studied five cycles.
Biocompatible co-polymer matrix has great importance for enzyme immobilization and subsequent biocatalytic applications to synthesize important organic moieties. Citronellyl laurate is a fatty-acid-ester having pleasant fruity aroma and widely used as/in emulsifier, lubricant in textile, paint or ink-additives, surfactants, perfumery and food-flavouring ingredient. In present study, Burkholderia cepacia lipase (BCL) was immobilized on biodegradable co-polymer of chitosan (CHI) and polyvinyl alcohol (PVA). The synthesized bio-catalyst {PVA:CHI:BCL (6:4:2.5)} was characterized by SEM, TGA, lipase assay and protein-content analysis. This biocatalyst was applied to synthesize citronellyl laurate in supercritical carbon-dioxide (SC-CO2) using response surface methodology with five-factor-three-level Box–Behnken-design to optimize reaction parameters (citronellol: 8.5 mmol; vinyl laurate: 19.87 mmol; biocatalyst: 175.6 mg; temperature: 46.02 °C; pressure: 8.81 MPa) which provided 94 ± 1.52% yield. The protocol is extended to synthesize various important 12 laurate compounds with excellent yield (90–98%) and noteworthy recyclability (upto studied 5 recycles). Interestingly, immobilized PVA/CHI/lipase biocatalyst showed 4-fold higher bio-catalytic activity than free lipase in SC-CO2. Moreover, the biocatalyst activity assessment study showed remarkable activity–stability of immobilized biocatalyst in SC-CO2 media as compared to free enzyme. Thus, present protocol demonstrated potential biocatalytic applications for synthesis of important laurate compounds with excellent recyclability in SC-CO2 as greener biocatalyst and reaction medium.
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