Magnetically responsive PA6 microparticles with immobilized laccase show high catalytic efficiency in the enzymatic treatment of catechol

• Published in: Catalysts 2021-02, Vol.11 (2), p.1-26
• Main Authors: Dencheva, Nadya Vasileva, Oliveira, Sandra Cristina Gomes, Braz, Joana Filipa Barros, Getya, Dariya, Malfois, Marc, Denchev, Z., Gitsov, Ivan
• Format: Article
• Language: English
• Subjects: Catechol oxidation; Enzyme immobilization; Laccase; Magnetic enzyme supports; Polyamide 6; Science & Technology
• ISSN: 2073-4344; 2073-4344
• DOI: 10.3390/catal11020239

Herewith we report the first attempt towards non-covalent immobilization of Trametes versicolor laccase on neat and magnetically responsive highly porous polyamide 6 (PA6) microparticles and their application for catechol oxidation. Four polyamide supports, namely neat PA6 and such carrying Fe, phosphate-coated Fe and Fe 3 O 4 cores were synthesized in suspension by activated anionic ring-opening polymerization (AAROP) of ε-caprolactam (ECL). Enzyme adsorption efficiency up to 92% was achieved in the immobilization process. All empty supports and PA6 laccase complexes were characterized by spectral and synchrotron WAXS/SAXS analyses. The activity of the immobilized laccase was evaluated using 2,2’-Azino-bis-(3- ethylbenzothiazoline-6-sulfonic acid (ABTS) and compared to the native enzyme. The PA6 laccase conjugates displayed up to 105% relative activity at room temperature, pH 4, 40 °C and 20 mM ionic strength (citrate buffer). The kinetic parameters of the ABTS oxidation were also determined. The reusability of the immobilized laccase-conjugates was proven for five consecutive oxidation cycles of catechol. The authors gratefully acknowledge the financial support of the project TSSiPRO NORTE01-0145-FEDER-000015, supported by the regional operation program NORTE2020, under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund, as well as the support by National Funds through Fundação para a Ciência e Tecnologia (FCT), project UID/CTM/50025/2019. D.G. and I.G. wish to thank the Research Foundation of the State of New York—Networks of Excellence and the McIntyre-Stennis program of the US Department of Agriculture for partial funding. N.D. is also grateful for the personal program-contract CTTI-51/18-IPC.