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Scientists are turning plastic pollution into vanilla flavouring

There's a plastic pollution crisis in the UK, and recycling doesn't go far enough to curb the issue. But researchers discovered a novel way to turn the most common plastics into a sought-after chemical
Around 50 million tonnes of the strong, lightweight plastic used for water bottles is produced around the world each year. Image: Pexels

The UK produces up to 1.5 million tonnes of plastic waste every year, choking rivers and blighting the ocean. But researchers have discovered a new way of cutting the country’s plastic pollution. Rather than burning it or putting it through lengthy and inefficient recycling processes they have a simpler suggestion: we should simply eat it.

Scientists from the University of Edinburgh have found a way to convert the plastic used for food packaging and water bottles into vanillin, the main component which gives vanilla beans their taste and smell.

The discovery “challenges the perception of plastic being a problematic waste” and instead shows it can be a valuable resource for creating some of the nation’s favourite products, according to Stephen Wallace, senior lecturer in biotechnology and co-author of the study.

Around 50 million tonnes of polyethylene terephthalate (PET) – the strong, lightweight plastic commonly used in everyday items – are generated around the world each year, and current methods for recycling it create products which still add to plastic pollution.

Scientists used lab-engineered E. coli bacteria to set off a series of chemical reactions which transformed PET into vanillin, which is widely used in food and cosmetics as well as in herbicides and household cleaning products.

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Global demand for vanillin outstrips the amount currently obtainable from nature by 37,000 tonnes. The use of one kilogram of vanilla beans requires more than 126,000 litres of water, meaning cutting reliance on them would benefit the planet beyond just cutting plastic pollution. 

This “really interesting use of microbial science” can boost sustainability efforts and help create a circular economy – in which we find ways to continually use the same finite resources instead of creating new waste – said Dr Ellis Crawford, publishing editor at the Royal Society of Chemistry.

Using microbes to turn waste plastics, which are harmful to the environment, into an important commodity which is needed in cosmetics and food is “a beautiful demonstration of green chemistry”, they said. 

The researchers believe the vanillin produced in this way would be safe for people to consume but that more tests are required to confirm it.

This is the first time scientists have used biology to upcycle plastic waste into a valuable chemical, said Joanna Sadler – a biochemist at the University of Edinburgh and co-author of the study – and has “very exciting implications for the circular economy”.

“The results from our research have major implications for the field of plastic sustainability and demonstrate the power of synthetic biology to address real-world challenges,” she added.

“To me, this is only the beginning. I think we are in a really exciting place now that we are realising we can do all sorts of things with waste plastic.”