Cytochrome P450 monooxygenase-mediated metabolic utilization of benzo[a]pyrene by Aspergillus species

Abstract

Soil-dwelling fungal species possess the versatile metabolic capability to degrade complex organic compounds that are toxic to humans, yet the mechanisms they employ remain largely unknown. Benzo[a]pyrene (BaP) is a pervasive carcinogenic contaminant, posing a significant concern for human health. Here, we report that several Aspergillus species are capable of degrading BaP. Exposing Aspergillus nidulans cells to BaP results in transcriptomic and metabolic changes associated with cellular growth and energy generation, implying that the fungus utilizes BaP as a growth substrate. Importantly, we identify and characterize the conserved bapA gene encoding a cytochrome P450 monooxygenase that is necessary for the metabolic utilization of BaP in Aspergillus. We further demonstrate that the fungal NF- Btype velvet regulators VeA and VelB are required for proper expression of bapA in response to nutrient limitation and BaP degradation in A. nidulans. Our study illuminates fundamental knowledge of fungal BaP metabolism and provides novel insights into enhancing bioremediation potential.