Cytochrome P450 monooxygenases involved in anthracene metabolism by the white-rot basidiomycete Phanerochaete chrysosporium
ABSTRACT Cytochrome P450 monooxygenases (P450s) involved in anthracene metabolism by the white-rot basidiomycete Phanerochaete chrysosporium were identified by comprehensive screening of both catalytic potentials and transcriptomic profiling. Functional screening of P. chrysosporium P450s (PcCYPs) revealed that 14 PcCYP species catalyze stepwise conversion of anthracene to anthraquinone via intermediate formation of anthrone. Moreover, transcriptomic profiling explored using a complementary DNA microarray system demonstrated that 12 PcCYPs are up-regulated in response to exogenous addition of anthracene. Among the up-regulated PcCYPs, five species showed catalytic activity against anthracene. Based upon both catalytic and transcriptional properties, these five species are most likely to play major roles in anthracene metabolic processes in vivo. Thus, the combination of functional screening and a microarray system may provide a novel strategy for obtaining a thorough understanding of the catalytic functions and biological impacts of PcCYPs.
SourceAvailable from: Panan Rerngsamran[Show abstract] [Hide abstract]
ABSTRACT: Three chromogenic substances with structures resembling those of polycyclic aromatic hydrocarbons (PAHs) were incorporated in culture medium in order to screen for fungi capable of degrading PAHs. Curvularia sp. F18, Lentinus sp. S5, and Phanerochaete sp. T20 were isolated and shown to have the ability to degrade both low- and highmolecular weight PAHs, with the most prominent degradation being observed with Phanerochaete sp. T20. Preliminary metabolite analysis of fluorene degradation by Phanerochaete sp. T20 using HPLC and GC-MS revealed that one of the early metabolites was 9-fluorenol, which is a less toxic substance. This fungus survived in 500 mg/l of PAH for at least 30 days. The fungus could degrade a mixture of four PAHs (25 mg/l each), resulting in the reduction of 97, 59, 39, and 47% of fluorene, phenanthrene, fluoranthene, and pyrene, respectively. This work demonstrates that Phanerochaete sp. T20 could be used to bioremediate environments contaminated with high concentrations and/or mixtures of PAHs.ScienceAsia 06/2012; 38:147–156. DOI:10.2306/scienceasia1513-1874.2012.38.147 · 0.35 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: The first steps of wood degradation by fungi lead to the release of toxic compounds known as extractives. To better understand how lignolytic fungi cope with the toxicity of these molecules, a transcriptomic analysis of Phanerochaete chrysosporium genes was performed in presence of oak acetonic extracts. It reveals that in complement to the extracellular machinery of degradation, intracellular antioxidant and detoxification systems contribute to the lignolytic capabilities of fungi presumably by preventing cellular damages and maintaining fungal health. Focusing on these systems, a glutathione transferase (PcGTT2.1) has been selected for functional characterization. This enzyme, not characterized so far in basidiomycetes, has been first classified as a GTT2 in comparison to the Saccharomyces cerevisiae isoform. However, a deeper analysis shows that GTT2.1 isoform has functionally evolved to reduce lipid peroxidation by recognizing high-molecular weight peroxides as substrates. Moreover, the GTT2.1 gene has been lost in some non-wood decay fungi. This example suggests that the intracellular detoxification system could have evolved concomitantly with the extracellular ligninolytic machinery in relation to the capacity of fungi to degrade wood.Applied and Environmental Microbiology 08/2014; 80(20). DOI:10.1128/AEM.02103-14 · 3.95 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: The white-rot fungus Phanerochaete chrysosporium was investigated for its capacity to degrade the herbicide diuron in liquid stationary cultures. The presence of diuron increased the production of lignin peroxidase in relation to control cultures but only barely affected the production of manganese peroxidase. The herbicide at the concentration of 7 μ g/mL did not cause any reduction in the biomass production and it was almost completely removed after 10 days. Concomitantly with the removal of diuron, two metabolites, DCPMU [1-(3,4-dichlorophenyl)-3-methylurea] and DCPU [(3,4-dichlorophenyl)urea], were detected in the culture medium at the concentrations of 0.74 μ g/mL and 0.06 μ g/mL, respectively. Crude extracellular ligninolytic enzymes were not efficient in the in vitro degradation of diuron. In addition, 1-aminobenzotriazole (ABT), a cytochrome P450 inhibitor, significantly inhibited both diuron degradation and metabolites production. Significant reduction in the toxicity evaluated by the Lactuca sativa L. bioassay was observed in the cultures after 10 days of cultivation. In conclusion, P. chrysosporium can efficiently metabolize diuron without the accumulation of toxic products.12/2013; 2013:251354. DOI:10.1155/2013/251354