title: Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by fungal enzymes: A review.
abstract: Polycyclic aromatic hydrocarbons (PAHs) are a large group of chemicals. They represent an important concern due to their widespread distribution in the environment, their resistance to biodegradation, their potential to bioaccumulate and their harmful effects. Several pilot treatments have been implemented to prevent economic consequences and deterioration of soil and water quality. As a promising option, fungal enzymes are regarded as a powerful choice for degradation of PAHs. Phanerochaete chrysosporium, Pleurotus ostreatus and Bjerkandera adusta are most commonly used for the degradation of such compounds due to their production of ligninolytic enzymes such as lignin peroxidase, manganese peroxidase and laccase. The rate of biodegradation depends on many culture conditions, such as temperature, oxygen, accessibility of nutrients and agitated or shallow culture. Moreover, the addition of biosurfactants can strongly modify the enzyme activity. The removal of PAHs is dependent on the ionization potential. The study of the kinetics is not completely comprehended, and it becomes more challenging when fungi are applied for bioremediation. Degradation studies in soil are much more complicated than liquid cultures because of the heterogeneity of soil, thus, many factors should be considered when studying soil bioremediation, such as desorption and bioavailability of PAHs. Different degradation pathways can be suggested. The peroxidases are heme-containing enzymes having common catalytic cycles. One molecule of hydrogen peroxide oxidizes the resting enzyme withdrawing two electrons. Subsequently, the peroxidase is reduced back in two steps of one electron oxidation. Laccases are copper-containing oxidases. They reduce molecular oxygen to water and oxidize phenolic compounds.
authors.affiliation: INRS-ETE, Université du Québec, 490 Rue de la Couronne, Québec, QC G1K 9A9, Canada.
authors.forename: Tayssir
authors.initials: T
authors.lastname: Kadri
authors.affiliation: INRS-ETE, Université du Québec, 490 Rue de la Couronne, Québec, QC G1K 9A9, Canada.
authors.forename: Tarek
authors.initials: T
authors.lastname: Rouissi
authors.affiliation: INRS-ETE, Université du Québec, 490 Rue de la Couronne, Québec, QC G1K 9A9, Canada. Electronic address: satinder.brar@ete.inrs.ca.
authors.forename: Satinder
authors.initials: S
authors.lastname: Kaur Brar
authors.affiliation: INRS-ETE, Université du Québec, 490 Rue de la Couronne, Québec, QC G1K 9A9, Canada.
authors.forename: Maximiliano
authors.initials: M
authors.lastname: Cledon
authors.affiliation: INRS-ETE, Université du Québec, 490 Rue de la Couronne, Québec, QC G1K 9A9, Canada.
authors.forename: Saurabhjyoti
authors.initials: S
authors.lastname: Sarma
authors.affiliation: CO(2) Solutions Inc., 2300, rue Jean-Perrin, Québec, QC G2C 1T9, Canada.
authors.forename: Mausam
authors.initials: M
authors.lastname: Verma
mesh_terms: D001673:Biodegradation, Environmental; D005658:Fungi / Q000201:enzymology*; D042845:Laccase / Q000378:metabolism; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000378:metabolism; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants; D042845:Laccase; D010544:Peroxidases; C042858:lignin peroxidase; C051129:manganese peroxidase
keywords: Biodegradation; Enzymes; Fungi; Polycyclic aromatic hydrocarbons (PAHs)