Scientists have developed a new biotechnological approach that makes it possible to convert plastic waste into a drug used to treat Parkinson’s disease — levodopa (L-DOPA), one of the main therapies for this neurodegenerative condition. The study, published in Nature Sustainability, demonstrates the potential of genetically engineered bacteria to transform plastic components into pharmaceutically valuable substances.

The method is based on recycling polyethylene terephthalate (PET), a common plastic used in food and beverage packaging. First, the plastic is broken down into terephthalic acid. Then, specially modified strains of the bacterium Escherichia coli convert this compound into levodopa through a series of biochemical reactions.

The system consists of two interacting microbial strains, which helped overcome key biochemical limitations. One strain converts the initial substance into intermediate compounds, while the second completes the synthesis of levodopa. This division of labor prevents enzyme inhibition and improves overall efficiency. Under optimized conditions, researchers achieved product concentrations of about 5 grams per liter, indicating high experimental efficiency.

Additional experiments showed that the technology works not only with pure chemical inputs but also with real-world waste, including used plastic bottles. In some cases, the conversion efficiency reached nearly 50%, producing enough levodopa for several therapeutic doses at early stages of the disease.

The researchers note that traditional levodopa production relies on petrochemical raw materials and involves energy-intensive processes that generate waste. The new method offers a more sustainable alternative, potentially addressing both plastic pollution and the pharmaceutical industry’s dependence on fossil resources.