METABOLISM OF XENOBIOTICS BY BEAUVERIA-BASSIANA

1. Diazepam, warfarin and testosterone were metabolized by whole resting cells of the fungus Beauveria bassiana IMI 12939 via oxidative reactions such as hydroxylation and N-demethylation. 2. Metabolism of each substrate was inhibited by the cytochrome P450 inhibitors SKF-525A and metyrapone, consistent with the involvement of this enzyme system in the metabolism of these drugs by B. bassiana. 3. Substrate concentration-dependent inhibition was observed during diazepam metabolism by this organism, as has been observed in some mammalian systems. 4. Unlike most mammalian P450 systems, the warfarin-metabolizing activity of B. bassiana could not be induced by growing the organism in the presence of phenobarbitone, beta-naphthoflavone, 3-methylcholanthrene, 1-benzylimidazole or warfarin. 5. Overall findings indicate that B. bassiana possesses an oxidative metabolizing system capable of producing metabolites found in mammalian systems.