Role of P450 Monooxygenases in the Degradation of the Endocrine-Disrupting Chemical Nonylphenol by the White Rot Fungus Phanerochaete chrysosporium

Abstract

The white rot fungus Phanerochaete chrysosporium extensively degraded the endocrine disruptor chemical nonylphenol (NP; 100% of 100 ppm) in both nutrient-limited cultures and nutrient-sufficient cultures. The P450 enzyme inhibitor piperonyl butoxide caused significant inhibition (ϳ75%) of the degradation activity in nutrient-rich malt extract (ME) cultures but no inhibition in defined low-nitrogen (LN) cultures, indicating an essential role of P450 monooxygenase(s) in NP degradation under nutrient-rich conditions. A genome-wide analysis using our custom-designed P450 microarray revealed significant induction of multiple P450 monooxygenase genes by NP: 18 genes were induced (2-to 195-fold) under nutrient-rich conditions, 17 genes were induced (2-to 6-fold) in LN cultures, and 3 were induced under both nutrient-rich and LN conditions. The P450 genes Pff 311b (corresponding to protein identification number [ID] 5852) and Pff 4a (protein ID 5001) showed extraordinarily high levels of induction (195-and 167-fold, respectively) in ME cultures. The P450 oxidoreductase (POR), glutathione S-transferase (gst), and cellulose metabolism genes were also induced in ME cultures. In contrast, certain metabolic genes, such as five of the peroxidase genes, showed partial downregulation by NP. This study provides the first evidence for the involvement of P450 enzymes in NP degradation by a white rot fungus and the first genome-wide identification of specific P450 genes responsive to an environmentally significant toxicant.

Transcriptomic Responses of Phanerochaete chrysosporium to Oak Acetonic Extracts: Focus on a New Glutathione Transferase

“…Members from CYP5144 and CYP63 exhibit catalytic activities toward environmentally persistent and toxic high-molecular-weight polycyclic aromatic compounds, such as phenanthrene, pyrene or benzo(a)pyrene, alkylphenols, and alkane (40,41). Evidence of the involvement of ProtID 131921 in the degradation of the endocrine disruptor chemical nonylphenol also has been demonstrated (42). Transcriptomic experiments showed that ProtID 139146 and 132579 gene expression is induced after anthracen and anthrone treatments (43).…”

Transcriptomic Profile of Lignocellulose Degradation from Trametes versicolor on Poplar Wood

“…Based on this result, it was deduced that the induction of P450 was important for lignin degradation. Overall, the expression patterns observed in T. versicolor grown on a complex lignocellulose substrate suggested that there were diverse strategies for lignin degradation, and thus provided clues about different mechanisms of delignification (Subramanian and Yadav 2009;Syed et al 2010;Ichinose 2013).…”

Atypical features of a Ure2p glutathione transferase from Phanerochaete chrysosporium

“…The bacterial strain deleted for EcYfcG exhibits an increasing sensitivity toward hydrogen peroxide [19]. In Aspergillus nidulans, the GSTA mutant is sensitive to xenobiotics and heavy metals [20] and in P. chrysosporium, the expression of PcUre2pB1 is upregulated in presence of nonylphenol [21]. In bacteria, EcYfcG might interact with glutathionylspermidin and perhaps utilizes it as a substrate or a regulatory molecule [3,4].…”