Identification of the cytochrome P450 involved in the degradation of neonicotinoid insecticide acetamiprid in Phanerochaete chrysosporium.

We previously reported that cytochrome P450 s play critical roles in neonicotinoid insecticide biodegradation by white-rot fungi. Here, we investigated the biodegradation of acetamiprid (ACET) by Phanerochaete chrysosporium to identify the cytochrome P450 involved in this degradation process. During a 20-day incubation period, P. chrysosporium degraded 21% and 51% of ACET in ligninolytic and nonligninolytic media, respectively. The degradation rate of ACET was markedly decreased by the addition of cytochrome P450 inhibitors. Recombinant cytochrome P450s in P. chrysosporium (PcCYP) were heterologously expressed in Saccharomyces cerevisiae strain AH22, and the PcCYP involved in ACET degradation was identified. The results showed that CYP5147A3 can degrade ACET, and two ACET metabolites, N'-cyano-N-methyl acetamidine and 6-chloro-3-pyridinemethanol, were identified. To the best of our knowledge, this study provides the first characterization of the fungal cytochrome P450 that is responsible for the degradation and detoxification of ACET.