title: Transformation of 2,4,6-trichlorophenol by free and immobilized fungal laccase.
abstract: Laccase from the white rot fungus Coriolus versicolor was immobilized on Celite R-637 by covalent binding with glutaraldehyde. After a sharp primary decline in activity (up to 50%), the retained enzyme activity was stable over a storage period of 33 days at 4 degrees C. A comparative study of soluble and immobilized laccases revealed the increased resistance of immobilized enzyme to the unfavourable effects of alkaline pH, high temperature and the action of inhibitors. A combination of these properties of immobilized laccase resulted in the ability to oxidize 2,4,6-trichlorophenol (2,4,6-TCP) at 50 degrees C at pH 7.0. The reactions of soluble and immobilized laccase with 2,4,6-TCP were examined in the presence and absence of redox mediators. 3,5-Dichlorocatechol, 2,6-dichloro-1,4-benzoquinone and 2,6-dichloro-1,4-hydroquinone were found to be the primary products of 2,4,6-TCP oxidation by laccase; oligo- and polymeric compounds were also found.
authors.affiliation: Institute of Biochemistry and Physiology of Microorganisms of Russian Academy of Sciences, Pushchino Moscow region. leont@ibpm.serpukhov.su
authors.forename: A A
authors.initials: AA
authors.lastname: Leontievsky
authors.forename: N M
authors.initials: NM
authors.lastname: Myasoedova
authors.forename: B P
authors.initials: BP
authors.lastname: Baskunov
authors.forename: L A
authors.initials: LA
authors.lastname: Golovleva
authors.forename: C
authors.initials: C
authors.lastname: Bucke
authors.forename: C S
authors.initials: CS
authors.lastname: Evans
mesh_terms: D001487:Basidiomycota / Q000201:enzymology*; D001711:Biotransformation; D002733:Chlorophenols / Q000493:pharmacokinetics*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D042845:Laccase; D010088:Oxidoreductases / Q000378:metabolism*; D012995:Solubility
chemical_list: D002733:Chlorophenols; D004800:Enzymes, Immobilized; D010088:Oxidoreductases; D042845:Laccase; C024564:2,4,6-trichlorophenol