A drug to treat Parkinson’s disease can be made from waste plastic bottles using a pioneering method, a study shows. 

The approach harnesses bacteria to transform post-consumer plastic into L-DOPA, a frontline medication for the neurological disorder. 

It is the first time a natural, biological process has been engineered to turn plastic waste into a therapeutic for a neurological disease, researchers say. 

Scientists at the University of Edinburgh engineered E. coli bacteria to turn a type of plastic used widely in food and drink packaging – polyethylene terephthalate, or PET – into L-DOPA. 

The process involves first breaking down PET waste – some 50 million tonnes of which are produced annually – into chemical building blocks of terephthalic acid. Molecules of terephthalic acid are then transformed into L-DOPA by the engineered bacteria through a series of biological reactions. 

It could pave the way for growth of a bio-upcycling industry for producing not only pharmaceuticals but a wide range of products including flavourings, fragrances, cosmetics, and industrial chemicals, they add. 

The team will next focus on advancing the technology towards industrial application. This will involve further optimising the process, improving its scalability, and further assessing its environmental and economic performance, the team says. 

Professor Stephen Wallace, of the University of Edinburgh’s School of Biological Sciences, who led the study, said: “This feels like just the beginning. If we can create medicines for neurological disease from a waste plastic bottle, it’s exciting to imagine what else this technology could achieve. Plastic waste is often seen as an environmental problem, but it also represents a vast, untapped source of carbon. By engineering biology to transform plastic into an essential medicine, we show how waste materials can be reimagined as valuable resources that support human health.”

Image: Professor Stephen Wallace harvesting engineered bacteria for analysis. Credit: Edinburgh Innovations