Evaluation of toxicity and degradation of a chlorophenol mixture by the laccase produced by Trametes pubescens.
In this study, the biodegradation of a mixture of 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP) using the laccase produced by the white-rot fungus Trametes pubescens CBS 696.94 was evaluated. Two laccase isoenzymes with molecular weights of about 60 and 120 kDa were identified in the enzymatic crude extract. The highest laccase activity with syringaldazine was observed with pH 6.0 and 60°C, while with 2,2-azino-bis(3-ethylbenzothiazoline-6) sulphonic acid the highest activity was observed between 50 and 60°C and 3.0-4.0 pH. A biodegradation of 100%, 99%, 82.1% and 41.1% for 2-CP, 2,4-DCP, 2,4,6-TCP and PCP, respectively, was observed after 4h of reaction. The reduction in chlorophenols concentration allowed 90% reduction in mixture toxicity. In summary, these results show the feasibility of a laccase enzymatic crude extract from T. pubescens for the reduction of concentration and toxicity of chlorophenols.
Chemical Engineering Department, Universidad de Los Andes, Bogotá, Colombia.
Ingrid J
IJ
Gaitan
Sandra C
SC
Medina
Juan C
JC
González
Alexander
A
Rodríguez
Angela J
AJ
Espejo
Johann F
JF
Osma
Víctor
V
Sarria
Carlos J
CJ
Alméciga-Díaz
Oscar F
OF
Sánchez
D001673:Biodegradation, Environmental; D002470:Cell Survival / Q000187:drug effects*; D002733:Chlorophenols / Q000737:chemistry* / Q000633:toxicity*; D042845:Laccase / Q000737:chemistry* / Q000378:metabolism*; D055454:Trametes / Q000201:enzymology*
D002733:Chlorophenols; D042845:Laccase