Catalytic phenol removal using entrapped cross-linked laccase aggregates

Area of Science:

• Biotechnology
• Environmental Science
• Enzyme Engineering

Background:

• Phenol contamination poses significant environmental risks.
• Enzyme immobilization is crucial for enhancing enzyme stability and reusability in industrial applications.
• Laccase is a versatile enzyme with potential for bioremediation of phenolic pollutants.

Purpose of the Study:

• To develop and characterize novel immobilized laccase species for efficient phenol removal.
• To optimize immobilization parameters for maximum laccase specific activity.
• To evaluate the stability and reusability of immobilized laccase for wastewater treatment.

Main Methods:

• Combinatorial immobilization strategy involving cross-linking and entrapment in mesoporous silica.
• Preparation of entrapped cross-linked enzyme aggregates (E-CLEAs).
• Characterization using FT-IR, SEM, and AFM; optimization of pH, temperature, time, and cross-linker concentration.

Main Results:

• E-CLEAs exhibited enhanced thermal and pH stability compared to free laccase.
• Immobilized laccase retained significant activity in both hydrophobic and hydrophilic solvents.
• E-CLEAs demonstrated good operational stability, maintaining 79% activity after 20 cycles, with improved storage stability (20.88 days half-life).

Conclusions:

• Entrapped cross-linked enzyme aggregates (E-CLEAs) represent a highly stable and reusable biocatalyst for phenol removal.
• The insolubilized laccase offers significant advantages for phenol-contaminated wastewater treatment.
• This immobilization approach provides a promising avenue for developing efficient enzymatic bioremediation systems.