Involvement of 3,4-dichlorophenol hydroxylase in degradation of 3,4- dichlorophenol by the white rot fungus Phanerochaete chrysosporium

C. Deschler , Robert Duran (1) , M. Junqua , C. Landou , J.-C. Salvado , P. Goulas

1 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

Phanerochaete chrysosporium was able to grow in a C-limited medium containing 3,4-dichlorophenol. In comparison with cultures without 3,4- dichlorophenol, we observed about 30% reduction of the biomass together with the lack of lignin peroxidase and manganese peroxidase production. A weak dechlorination was observed but only methylated dichloroaromatic products such as 3,4-dichloroanisole, 4,5-dichloroguaiacol, and 4,5-dichloroveratrole were identified as chlorinated metabolites showing that methylation, but also hydroxylation reactions occurred. To confirm this hydroxylation reaction we have studied the degradation of 3,4-dichlorophenol, and of several chlorinated metabolites by mycelial pellets of P. chrysosporium lacking peroxidase activity. Under these conditions the degradation and the dechlorination of 3,4-dichlorophenol increased strongly and the amount of chloride recovered was 80% of the stoichiometric amount recoverable. We observed similar results with 4,5-dichlorocatechol. An NADPH-dependent 3,4- dichlorophenol hydroxylase was detected in cell free extracts and 4,5- dichlorocatechol was identified as hydroxylation product.

Domaines: Chimie

C. Deschler, Robert Duran, M. Junqua, C. Landou, J.-C. Salvado, et al.. Involvement of 3,4-dichlorophenol hydroxylase in degradation of 3,4- dichlorophenol by the white rot fungus Phanerochaete chrysosporium. Journal of Molecular Catalysis B: Enzymatic, 1998, 5 (1-4), pp.423-428. ⟨10.1016/S1381-1177(98)00056-3⟩. ⟨hal-01841804⟩