title: Preparation and characterization of cross-linked laccase aggregates and their application to the elimination of endocrine disrupting chemicals.
abstract: Laccase from the white rot fungus Coriolopsis polyzona was immobilized for the first time through the formation of cross-linked enzyme aggregates (CLEAs). Laccase CLEAs were produced by using 1000g of polyethylene glycol per liter of enzyme solution as precipitant and 200muM of glutaraldehyde as a cross-linking agent. These CLEAs had a laccase activity of 148Ug(-1) and an activity recovery of 60.2% when using 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) as substrate. CLEAs formed by co-aggregation with bovine serum albumin (BSA) as a stabilizer showed lower laccase activity and affinity for ABTS than those without BSA. The CLEAs co-aggregated with BSA showed higher residual activity against a protease, NaN(3), EDTA, methanol and acetone. The thermoresistance was higher for CLEAs than for free laccase and also higher for CLEAs co-aggregated with BSA than for simple CLEAs when tested at a pH of 3 and a temperature of 40 degrees C. Finally, laccase CLEAs were tested for their capacity to eliminate the known or suspected endocrine disrupting chemicals (EDCs) nonylphenol, bisphenol A and triclosan in a fluidized bed reactor. A 100-ml reactor with 0.5mg of laccase CLEAs operated continuously at a hydraulic retention time of 150min at room temperature and pH 5 could remove all three EDCs from a 5mgl(-1) solution.
authors: Department of Chemical Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Quebec, Canada J1K 2R1.
authors: Hubert
authors: H
authors: Cabana
authors: J Peter
authors: JP
authors: Jones
authors: Spiros N
authors: SN
authors: Agathos
mesh_terms: D000818:Animals; D001559:Benzhydryl Compounds; D019149:Bioreactors; D001709:Biotechnology; D002417:Cattle; D003432:Cross-Linking Reagents; D052244:Endocrine Disruptors / Q000302:isolation & purification*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D042845:Laccase / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010636:Phenols / Q000302:isolation & purification; D020072:Polyporales / Q000201:enzymology; D012710:Serum Albumin, Bovine; D013696:Temperature; D014260:Triclosan / Q000302:isolation & purification; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D003432:Cross-Linking Reagents; D052244:Endocrine Disruptors; D004800:Enzymes, Immobilized; D042845:Laccase; D010636:Phenols; D012710:Serum Albumin, Bovine; D014260:Triclosan; C025256:nonylphenol; C006780:bisphenol A; D000098826:Bisphenol A Compounds