Activated Carbon Functionalization for Lipase Immobilization: Characterization, Hydrolytic Activity, and Ethyl...

Area of Science:

• Biotechnology
• Enzyme Immobilization
• Green Chemistry

Background:

• Enzyme immobilization is crucial for developing reusable biocatalysts.
• Activated carbon modifications offer promising supports for enzyme immobilization.
• Developing sustainable methods for ester synthesis is an industrial priority.

Purpose of the Study:

• To evaluate genipin (GAC), metal-associated (MAC), and genipin-metal (GMAC) activated carbon modifications for lipase immobilization.
• To assess the performance of immobilized lipases (porcine pancreatic lipase - PPL and Candida rugosa lipase - CRL) in ethyl lactate synthesis.
• To investigate the reusability and stability of the synthesized biocatalysts.

Main Methods:

• Surface modification of activated carbon with genipin and/or metal particles.
• Immobilization of PPL and CRL onto modified activated carbon supports.
• Enzyme activity assays and esterification reaction monitoring (ethyl lactate synthesis).
• Evaluation of biocatalyst stability over multiple reaction cycles.

Main Results:

• Immobilization yields exceeded 87% for all adsorbents.
• Metalized activated carbons (MAC and GMAC) showed the highest hydrolytic activities (48.1 U for PPL, 51.6 U for CRL).
• Immobilized enzymes achieved >90% ethyl lactate conversion, with PPL GMAC reaching 94.2%.
• Biocatalysts maintained >80% conversion after five cycles, demonstrating excellent reusability and stability.

Conclusions:

• Genipin and metal particle modifications enhance activated carbon's suitability for lipase immobilization.
• The synthesized biocatalysts exhibit high catalytic activity and stability for ester synthesis.
• These reusable biocatalysts offer a sustainable approach for producing industrially relevant ester compounds.