Affiliation: | 1. Department of Pharmacology & Pharmaceutical Sciences, University of Southern California, 1985 Zonal Ave, Los Angeles, CA 90033 USA;2. Donald P. and Katherine B. Loker Hydrocarbon Institute and Department of Chemistry, University of Southern California, 837 Bloom Walk, Los Angeles, CA 90089 USA Wrigley Institute for Environmental Studies, University of Southern California, 3454 Trousdale Parkway, Los Angeles, CA 90089 USA These authors contributed equally to this work. Contribution: Data curation (lead), Formal analysis (lead), Investigation (lead), Methodology (lead), Writing - original draft (lead), Writing - review & editing (lead);3. Department of Pharmacology & Pharmaceutical Sciences, University of Southern California, 1985 Zonal Ave, Los Angeles, CA 90033 USA Contribution: Investigation (supporting), Methodology (supporting);4. Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045 USA;5. Donald P. and Katherine B. Loker Hydrocarbon Institute and Department of Chemistry, University of Southern California, 837 Bloom Walk, Los Angeles, CA 90089 USA |
Abstract: | Waste plastics represent major environmental and economic burdens due to their ubiquity, slow breakdown rates, and inadequacy of current recycling routes. Polyethylenes are particularly problematic, because they lack robust recycling approaches despite being the most abundant plastics in use today. We report a novel chemical and biological approach for the rapid conversion of polyethylenes into structurally complex and pharmacologically active compounds. We present conditions for aerobic, catalytic digestion of polyethylenes collected from post-consumer and oceanic waste streams, creating carboxylic diacids that can then be used as a carbon source by the fungus Aspergillus nidulans. As a proof of principle, we have engineered strains of A. nidulans to synthesize the fungal secondary metabolites asperbenzaldehyde, citreoviridin, and mutilin when grown on these digestion products. This hybrid approach considerably expands the range of products to which polyethylenes can be upcycled. |