title: Morphological changes and growth of filamentous fungi in the presence of high concentrations of PAHs.
abstract: In this study, we evaluated the effect of low and high molecular weight polycyclic aromatic hydrocarbons (PAHs), i.e., Phenanthrene, Pyrene and Benzo[a]pyrene, on the radial growth and morphology of the PAH-degrading fungal strains Aspergillus nomius H7 and Trichoderma asperellum H15. The presence of PAHs in solid medium produced significant detrimental effects on the radial growth of A. nomius H7 at 4,000 and 6,000 mg L(-1) and changes in mycelium pigmentation, abundance and sporulation ability at 1,000-6,000 mg L(-1). In contrast, the radial growth of T. asperellum H15 was not affected at any of the doses tested, although sporulation was observed only up to 4,000 mg L(-1) and as with the H7 strain, some visible changes in sporulation patterns and mycelium pigmentation were observed. Our results suggest that fungal strains exposed to high doses of PAHs significantly vary in their growth rates and sporulation characteristics in response to the physiological and defense mechanisms that affect both pigment production and conidiation processes. This finding is relevant for obtaining a better understanding of fungal adaptation in PAH-polluted environments and for developing and implementing adequate strategies for the remediation of contaminated soils.
authors.affiliation: Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Tlaxcala, México.
authors.forename: German
authors.initials: G
authors.lastname: Zafra
authors.affiliation: Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Tlaxcala, México.
authors.forename: Angel E
authors.initials: AE
authors.lastname: Absalón
authors.affiliation: Instituto Politécnico Nacional, Centro de Investigación en Biotecnología Aplicada, Tlaxcala, México.
authors.forename: Diana V
authors.initials: DV
authors.lastname: Cortés-Espinosa
mesh_terms: D001230:Aspergillus / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D001564:Benzo(a)pyrene / Q000494:pharmacology*; D001673:Biodegradation, Environmental; D025282:Mycelium / Q000187:drug effects*; D010616:Phenanthrenes / Q000494:pharmacology*; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism / Q000494:pharmacology*; D011721:Pyrenes / Q000494:pharmacology*; D012988:Soil Microbiology; D012989:Soil Pollutants; D013172:Spores, Fungal / Q000187:drug effects*; D014242:Trichoderma / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism
chemical_list: D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D012989:Soil Pollutants; D001564:Benzo(a)pyrene; C031181:phenanthrene; C030984:pyrene
keywords: bioremediation; fungal physiology; polycyclic aromatic hydrocarbons (PAHs); radial growth; sporulation