Transformation of 2,4,6-trichlorophenol by free and immobilized fungal laccase.
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.
Leontievsky
A A
AA
Institute of Biochemistry and Physiology of Microorganisms of Russian Academy of Sciences, Pushchino Moscow region. leont@ibpm.serpukhov.su
Myasoedova
N M
NM
Baskunov
B P
BP
Golovleva
L A
LA
Bucke
C
C
Evans
C S
CS
D001487:Basidiomycota / Q000201:enzymology*; D001711:Biotransformation; D002733:Chlorophenols / Q000493:pharmacokinetics*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D042845:Laccase; D010088:Oxidoreductases / Q000378:metabolism*; D012995:Solubility
D002733:Chlorophenols; D004800:Enzymes, Immobilized; D010088:Oxidoreductases; D042845:Laccase; C024564:2,4,6-trichlorophenol