The ubiquity and myriad applications of plastics make them integral to modern life. About 400 million tons of plastic are produced annually, and this amount increases every year. Unfortunately, most plastics are eventually released into the environment. This pollution can persist for hundreds of years and is detrimental to land use efficiency, aquatic infrastructure, ecosystems, and public health. Diminishing plastic pollution would greatly benefit environmental preservation and global sustainability. Biodegradation is emerging as a promising solution to the plastic crisis. However, a key bottleneck to achieving large-scale plastic-biodegrading systems is a poor understanding of how plastic biodegradation happens at the molecular level. We are investigating the biodegradation of two of the most common plastics, polystyrene and polyamide 66, by the white-rot fungus Phanerodontia chrysosporium and microbial isolates from the Dane County Landfill. We are using P. chrysosporium as a model to develop methods for assessing plastic degradation. Specifically, we are using gel permeation chromatography, Fourier transform infrared spectroscopy, nuclear magnetic resonance (NMR), liquid/gas chromatography mass spectrometry, and scanning electron microscopy to validate and characterize plastic degradation by P. chrysosporium. Conversely, we are culturing isolates from the Dane County Landfill and enriching them for growth on plastics as the sole carbon source. We will culture these isolates on isotopically labeled polymers and evaluate the enrichment of isotopes into biomass using NMR and sensitive mass spectrometry techniques. Then, we will use genomics, transcriptomics, and proteomics to pinpoint the enzymes and metabolic pathways involved in plastic biodegradation by landfill isolates. Finally, we will express candidate plastic-degrading enzymes in Pichia pastoris and use in vivo assays followed by physiochemical analyses to determine whether these enzymes can act on plastics. This research will establish standardized methods for molecular-level characterization of plastic degradation, fill critical knowledge gaps about how plastics are biodegraded, and deliver enzymes, metabolic pathways, and organisms that can be exploited for large-scale plastic degradation efforts.

Molecular mechanisms of plastic biodegradation

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.