Biomimetic mineralization of lipase@MOF biocatalyst for ease of biodiesel synthesis: Structural insights into the catalytic behavior

• Lipase@ZIF-8 biocomposites registered a superior enzyme-substrate affinity. • Conformational rearrangement of lipase occurred in porous zeolite-like topologies. • Lipase@ZIF-8 biocatalysts exhibited certain substrate-selectivity. • ZIF-8 served as protective coating for improved stability and reusability of lipase. • Lipase@ZIF-8 remained approximate 60% of biodiesel yield even after five consecutive cycles. A hybrid lipase@ZIF-8 biocatalyst was fabricated via a facile one-pot approach and coordination-driven self-assembly strategy. Entrapment immobilization of lipase in metal–organic frameworks (MOFs) was meticulously validated. The reduced K m value and apparent activation energy confirmed that the lipase@ZIF-8 registered a superior enzyme-substrate affinity than free ones. A concomitant conformational rearrangement occurred as lipase was encapsulated into the porous zeolite-like topologies, wherein lipase architectures presented more flexibility in character. An approximate 75% biodiesel yield was achieved when the biocomposites-catalyzed transesterification was conducted at given conditions. Notably, the lipase@ZIF-8 exhibited certain substrate-selectivity by deciphering the discrepancy in fatty acid profiles of the resulting biodiesel. Besides, the lipase@ZIF-8 biocomposites showed reasonable reusability and remained around 80% of initial activity after five cycles of transesterification. Consequently, the encapsulation of lipase into MOFs is a viable and sustainable avenue to address free lipase's intrinsic limitation, and underscores the immense potential in biodiesel production.