Eggshell membrane as feedstock in enzyme immobilization

Area of Science:

• Biotechnology
• Environmental Science
• Enzyme Engineering

Background:

• Eggshell membrane is an abundant, low-cost byproduct suitable for enzyme immobilization.
• Laccase enzyme from Trametes versicolor is a powerful biocatalyst for degrading phenolic compounds like syringic acid.
• Efficient enzyme immobilization is crucial for industrial applications and waste treatment.

Purpose of the Study:

• To investigate and optimize eggshell membrane as a carrier for immobilizing Trametes versicolor laccase.
• To evaluate different immobilization methods (solution incubation vs. enzyme-dropping) and chemical treatments (covalent vs. physical) for laccase.
• To determine the most effective protocol for syringic acid degradation using immobilized laccase.

Main Methods:

• Eggshell membrane was pre-treated using periodate oxidation and NiCl2.
• Laccase was immobilized via incubation in solution or enzyme-dropping.
• Covalent and physical immobilization techniques were tested with native and oxidized laccase.
• Syringic acid degradation efficiency and enzyme reusability were assessed.

Main Results:

• Immobilization of periodate-oxidized laccase on NiCl2-pretreated eggshell membrane via solution incubation achieved 1300 U/Kg activity with 30% residual activity after 6 reuses.
• Enzyme-dropping protocol using covalent immobilization with glutaraldehyde resulted in higher activity (3500 U/Kg) and 45% residual activity after 6 reuses.
• Both methods demonstrated the potential of eggshell membrane for effective laccase immobilization.

Conclusions:

• Eggshell membrane is a viable and cost-effective carrier for laccase immobilization.
• The enzyme-dropping method with covalent cross-linking using glutaraldehyde offers superior performance for syringic acid degradation.
• Optimized immobilized laccase systems can be applied in bioremediation and industrial processes.