Waste Plastic Turned into Parkinson's Drug Thanks to Helpful Bacteria

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

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

It’s the first time a biological process has achieved this, and the scientists behind the breakthrough said it would be a more sustainable method of making pharmaceuticals, which normally rely on the use of finite fossil fuels.

The story comes from the University of Edinburgh, where the team led by Dr. Stephen Wallace engineered E. coli bacteria to turn a type of plastic used widely in food and drink packaging—polyethylene terephthalate, or PET—into L-DOPA.

Some 50 million metric tons of PET are produced annually, and the process involves first breaking the plastic down 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.

“This feels like just the beginning,” said Wallace, who works as a professor at the University’s School of Biological Sciences.

“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.”

There is an urgent need for new methods to recycle PET , the team says. Existing recycling processes are not completely efficient and still contribute to plastic pollution worldwide.

L-DOPA is the precursor to the neurotransmitters dopamine, norepinephrine, and epinephrine, and in addition to Parkinson’s, is sold over the counter as a supplement and for treatment of Restless Leg Syndrome.

“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,” said Wallace.

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Having now demonstrated the production and isolation of L-DOPA at preparative scale, the team will next focus on advancing the technology towards industrial application which will involve further optimizing the process, improving its scalability, and further assessing its environmental and economic performance, the team says.