Summary: Scientists have developed a bio-upcycling method that converts plastic waste into L-DOPA, the primary medication used to treat Parkinson’s disease.
Researchers engineered strains of E. coli to transform polyethylene terephthalate (PET) — the plastic commonly found in beverage bottles and food packaging — into a high-value therapeutic compound. This work demonstrates the first engineered biological route that repurposes plastic pollution into an active pharmaceutical ingredient for a neurological disorder.
Key Facts
- The process: Waste PET is depolymerized to its monomer terephthalic acid, which is then used by engineered E. coli to carry out a sequence of biotransformations that yield L-DOPA.
- Scale of waste: Approximately 50 million tonnes of PET are produced each year; this technique offers a route to valorize that carbon rather than allow it to accumulate in landfills or the environment.
- Sustainability: Conventional pharmaceutical production depends heavily on finite fossil feedstocks and energy-intensive chemistry. Converting plastic waste into drug precursors uses an abundant, underutilized carbon source and biological fermentation, reducing reliance on fossil inputs.
- Broader potential: The same Carbon-Loop approach could be adapted to produce fragrances, flavorings, cosmetics and a range of industrial chemicals from plastic-derived carbon.
- Next steps: After demonstrating production and isolation of L-DOPA at preparative scale, the team will optimize process efficiency, improve scalability, and evaluate environmental and economic performance for industrial deployment.
Source: University of Edinburgh
A frontline Parkinson’s drug produced from waste plastic bottles
A team at the University of Edinburgh has engineered bacteria to convert post-consumer PET into L-DOPA, a key medicine used to manage Parkinson’s disease. The approach combines plastic depolymerization with synthetic biology to reimagine plastic waste as a feedstock for high-value biomanufacturing.
The process begins by breaking PET into terephthalic acid, its chemical building block. Engineered E. coli strains then convert terephthalic acid through a tailored sequence of enzymatic reactions into L-DOPA. According to the researchers, the final product is chemically identical to L-DOPA made by conventional manufacturing methods.
Producing pharmaceuticals from plastic waste could offer environmental advantages over standard methods that rely on finite oil- and gas-derived feedstocks. The team emphasizes the urgent need for improved PET recycling: current mechanical and chemical recycling routes are incomplete and still contribute to pollution. This bio-upcycling route captures the carbon in plastic and redirects it into valuable products rather than losing it to landfill, incineration or the natural environment.
Beyond pharmaceuticals, the researchers envision a broader Carbon-Loop industry. By using engineered microbes and tailored bioprocesses, the same principle could be applied to create fragrances, flavorings, cosmetics and various industrial chemicals from plastic-derived carbon, opening new markets for waste-derived materials.
Having validated the concept at preparative laboratory scale, the team is now focused on scaling the technology. Future work will target process optimization, scale-up, and detailed assessments of environmental footprint and economic viability to support industrial adoption.
The study is published in the journal Nature Sustainability. The research received funding from UK Research and Innovation (UKRI) and the Industrial Biotechnology Innovation Centre (IBioIC), with Impact Solutions as an industry partner. The work was undertaken within the Carbon-Loop Sustainable Biomanufacturing Hub (C-Loop), supported by the Engineering and Physical Sciences Research Council (EPSRC), and supported by Edinburgh Innovations for commercial development.
Professor Stephen Wallace, who led the study in the School of Biological Sciences, said the result opens new possibilities: turning a waste plastic bottle into a medicine demonstrates how engineered biology can transform waste carbon into resources that support human health. Other project leaders and partners highlighted the potential for engineered biological systems to redesign waste streams and support sustainable manufacturing at scale.
Key Questions Answered:
A: In a technical sense, yes — the microbes use carbon from plastic as the raw material. However, the plastic is broken down and fully transformed at the molecular level. The resulting L-DOPA is the same chemical compound as that produced by standard methods.
A: Traditional recycling often downcycles plastics into lower-value products. This approach is upcycling: it converts low-value waste into a high-value pharmaceutical, increasing the resource value of the original material.
A: Potentially. Using an abundant, low-cost waste feedstock and biological manufacturing could lower production costs as the technology matures and scales, but further work is needed to demonstrate commercial cost advantages.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by staff.
About this Parkinson’s disease research news
Author: Corin Campbell
Source: University of Edinburgh
Contact: Corin Campbell – University of Edinburgh
Image: Image credited to Neuroscience News
Original Research: Findings published in Nature Sustainability