Degradation of 2-chlorophenol and formation of 2-chloro-1,4-benzoquinone by mycelia and cell-free crude culture liquids ofTrametes versicolor in relation to extracellular laccase activity

Abstract

The white-rot fungus Trametes versicolor was used to study the influence of extracellular laccase activity on the degradation of 2-chlorophenol (2-CP) and the formation of metabolites under conditions, characterized by the absence of other phenol-oxidizing enzymes. 2-CP enhanced the production of extracellular laccase by fungal mycelia. The formation of the metabolite 2-chloro-1,4-benzoquinone (2-CIBQ) was found to be correlated with extracellular laccase activity. In cell-free crude culture liquids laccase was responsible for the oxidation of 2-CP. In contrast to this, the disappearance of 2-CP caused by the entire organism did not correlate with extracellular laccase activity. The primary oxidative step during the degradation of this compound can thus only partially be attributed to extracellular laccase; indicating the involvement of cell-bound processes.