title: Degradation of Bunker C Fuel Oil by White-Rot Fungi in Sawdust Cultures Suggests Potential Applications in Bioremediation.
abstract: Fungal lignocellulolytic enzymes are promising agents for oxidizing pollutants. This study investigated degradation of Number 6 "Bunker C" fuel oil compounds by the white-rot fungi Irpex lacteus, Trichaptum biforme, Phlebia radiata, Trametes versicolor, and Pleurotus ostreatus (Basidiomycota, Agaricomycetes). Averaging across all studied species, 98.1%, 48.6%, and 76.4% of the initial Bunker C C10 alkane, C14 alkane, and phenanthrene, respectively were degraded after 180 days of fungal growth on pine media. This study also investigated whether Bunker C oil induces changes in gene expression in the white-rot fungus Punctularia strigosozonata, for which a complete reference genome is available. After 20 days of growth, a monokaryon P. strigosozonata strain degraded 99% of the initial C10 alkane in both pine and aspen media but did not affect the amounts of the C14 alkane or phenanthrene. Differential gene expression analysis identified 119 genes with ≥ log2(2-fold) greater expression in one or more treatment comparisons. Six genes were significantly upregulated in media containing oil; these genes included three enzymes with potential roles in xenobiotic biotransformation. Carbohydrate metabolism genes showing differential expression significantly accumulated transcripts on aspen vs. pine substrates, perhaps reflecting white-rot adaptations to growth on hardwood substrates. The mechanisms by which P. strigosozonata may degrade complex oil compounds remain obscure, but degradation results of the 180-day cultures suggest that diverse white-rot fungi have promise for bioremediation of petroleum fuels.
authors.affiliation: Biology Department, Clark University, Worcester, MA, United States of America.
authors.forename: Darcy
authors.initials: D
authors.lastname: Young
authors.affiliation: School of Engineering, Brown University, Providence, RI, United States of America.
authors.forename: James
authors.initials: J
authors.lastname: Rice
authors.affiliation: Biology Department, Clark University, Worcester, MA, United States of America.
authors.forename: Rachael
authors.initials: R
authors.lastname: Martin
authors.affiliation: Joint Genome Institute, Walnut Creek, CA, United States of America.
authors.forename: Erika
authors.initials: E
authors.lastname: Lindquist
authors.affiliation: Joint Genome Institute, Walnut Creek, CA, United States of America.
authors.forename: Anna
authors.initials: A
authors.lastname: Lipzen
authors.affiliation: Joint Genome Institute, Walnut Creek, CA, United States of America.
authors.forename: Igor
authors.initials: I
authors.lastname: Grigoriev
authors.affiliation: Biology Department, Clark University, Worcester, MA, United States of America.
authors.forename: David
authors.initials: D
authors.lastname: Hibbett
mesh_terms: D001487:Basidiomycota / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D050260:Carbohydrate Metabolism / Q000235:genetics; D004785:Environmental Pollutants / Q000737:chemistry; D005648:Fuel Oils / Q000633:toxicity*; D005658:Fungi / Q000737:chemistry* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D006801:Humans; D016877:Oxidants
chemical_list: D004785:Environmental Pollutants; D005648:Fuel Oils; D016877:Oxidants