title: Synthesis and characterization of combined cross-linked laccase and tyrosinase aggregates transforming acetaminophen as a model phenolic compound in wastewaters.
abstract: Laccase (EC 1.10.3.2) and tyrosinases (EC 1.14.18.1) are ubiquitous enzymes present in nature as they are known to originate from bacteria, fungi, plants, etc. Both laccase and tyrosinase are copper-containing phenoloxidases requiring readily available O2 without auxiliary cofactor for their catalytic transformation of numerous phenolic substrates. In the present study, laccase and tyrosinase have been insolubilized as combined crosslinked enzyme aggregates (combi-CLEA) using chitosan, a renewable and biodegradable polymer, as crosslinker. The combi-CLEA, with specific activity of 12.3 U/g for laccase and 167.4 U/g for tyrosinase, exhibited high enzymatic activity at pH5-8 and temperature at 5-30°C, significant resistance to denaturation and no diffusional restriction to its active site based upon the Michaelis-Menten kinetic parameters. Subsequently, the combi-CLEA was applied to the transformation of acetaminophen as a model phenolic compound in samples of real wastewaters in order to evaluate the potential efficiency of the biocatalyst. In batch mode the combi-CLEA transformed more than 80% to nearly 100% of acetaminophen from the municipal wastewater and more than 90% from the hospital wastewater. UPLC-MS analysis of acetaminophen metabolites showed the formation of its oligomers as dimers, trimers and tetramers due to the laccase and 3-hydroxyacetaminophen due to the tyrosinase.
authors.affiliation: Department of Chemical Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, Québec, Canada.
authors.forename: Sidy
authors.initials: S
authors.lastname: Ba
authors.affiliation: Department of Chemistry, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, Québec, Canada.
authors.forename: Lounes
authors.initials: L
authors.lastname: Haroune
authors.affiliation: Department of Chemical Engineering, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain.
authors.forename: Carles
authors.initials: C
authors.lastname: Cruz-Morató
authors.affiliation: Department of Chemical Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, Québec, Canada.
authors.forename: Chloé
authors.initials: C
authors.lastname: Jacquet
authors.affiliation: Department of Civil Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, Québec, Canada.
authors.forename: Imad E
authors.initials: IE
authors.lastname: Touahar
authors.affiliation: Department of Chemistry, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, Québec, Canada.
authors.forename: Jean-Phillipe
authors.initials: JP
authors.lastname: Bellenger
authors.affiliation: Department of Chemistry, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, Québec, Canada.
authors.forename: Claude Y
authors.initials: CY
authors.lastname: Legault
authors.affiliation: Department of Chemical Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, Québec, Canada.
authors.forename: J Peter
authors.initials: JP
authors.lastname: Jones
authors.affiliation: Department of Civil Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke J1K 2R1, Québec, Canada; Etienne-Le Bel Centre de Recherche Clinique, Centre Hospitalier Universitaire de Sherbrooke, 3001, 12(e) Avenue Nord, Sherbrooke J1K 2R1, Québec, Canada. Electronic address: Hubert.Cabana@USherbrooke.ca.
authors.forename: Hubert
authors.initials: H
authors.lastname: Cabana
mesh_terms: D000082:Acetaminophen / Q000737:chemistry*; D007700:Kinetics; D042845:Laccase / Q000737:chemistry*; D008956:Models, Chemical; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*; D013696:Temperature; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000082:Acetaminophen; D042845:Laccase; D014442:Monophenol Monooxygenase; D010636:Phenols; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Acetaminophen; Characterization; Combi-CLEA; Laccase; Tyrosinase; Wastewaters