Manganese-enhanced biotransformation of atrazine by the white rot fungus Pleurotus pulmonarius and its correlation with oxidation activity

Abstract

Manganese enhanced atrazine transformation by the fungus Pleurotus pulmonarius when added to a liquid culture medium at concentrations of up to 300 microM. Both N-dealkylated and propylhydroxylated metabolites accumulated in the culture medium, with the former accumulating to a greater extent than did the latter. Lipid peroxidation, oxygenase and peroxidase activities, and the cytochrome P-450 concentration increased. In addition, an increase in the spectral interactions between atrazine and components in the cell extract was observed. Antioxidants, mainly nordihydroguaiaretic acid, which inhibits lipoxygenase, peroxidase, and P-450 activities, and piperonyl butoxide, which inhibits P-450 activity, inhibited atrazine transformation by the mycelium. It is suggested that the stimulation of oxidative activity by Mn might be responsible for increasing the biotransformation of atrazine and for nonspecific transformations of other xenobiotic compounds.