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Laccase-Based CLEAs: Chitosan as a Novel Cross-Linking Agent
Alexandre Arsenault1, Hubert Cabana, J Peter Jones
1Environmental Engineering Laboratory, Department of Civil Engineering, University of Sherbrooke, 2 500 Boulevard de l'Université, Sherbrooke, QC, Canada J1K 2R1.
Enzyme Research
|August 4, 2011
Summary
Researchers developed cross-linked enzyme aggregates (CLEAs) from Coriolopsis polyzona laccase using chitosan. These novel biocatalysts show enhanced thermal stability and activity, offering improved performance over free laccase.
Area of Science:
- Biocatalysis and Enzyme Engineering
- Biotechnology
- Protein Immobilization
Background:
- Laccase enzymes are valuable biocatalysts with broad applications.
- Immobilization of enzymes, such as laccase, can enhance their stability and reusability.
- Cross-linked enzyme aggregates (CLEAs) offer a promising approach for enzyme immobilization.
Purpose of the Study:
- To develop and characterize chitosan-based cross-linked enzyme aggregates (CLEAs) of laccase from Coriolopsis polyzona.
- To evaluate the specific activity and thermal stability of the novel laccase CLEAs.
- To optimize the formation conditions for efficient laccase-based CLEAs.
Main Methods:
- Enzyme precipitation using ammonium sulfate followed by simultaneous cross-linking with chitosan and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride.
- Measurement of specific activity using 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) as a substrate.
- Assessment of thermal and chemical stability under various denaturing conditions.
- Optimization of CLEA formation using response surface methodology.
Main Results:
- Laccase CLEAs were successfully prepared using chitosan as a cross-linking agent.
- Specific activities of up to 737 U/g were achieved with ABTS as substrate.
- The laccase CLEAs exhibited improved thermal stability compared to free laccase, with enhanced substrate oxidation capacity under thermal stress.
- Optimal formation conditions involved 24 hours of incubation at pH 3 and 4°C without agitation.
Conclusions:
- Chitosan-based laccase CLEAs represent an efficient and stabilized biocatalyst.
- The developed CLEAs demonstrate superior thermal stability and activity, making them suitable for industrial applications.
- Optimization of formation conditions is crucial for maximizing the performance of laccase CLEAs.
