Scientists Can Now Turn Used Soda Bottles Into Vanilla Flavoring

Yes, it’s weird—but possible with mutant enzymes and genetically engineered bacteria.

Laborers sort through polyethylene terephthalate (PET) bottles at a recycling factory in BangladeshKazi Salahuddin Razu/NurPhoto/Getty Images

This story was originally published by the Guardian and is reproduced here as part of the Climate Desk collaboration. 

Plastic bottles have been converted into vanilla flavoring using genetically engineered bacteria, the first time a valuable chemical has been brewed from waste plastic.

Upcycling plastic bottles into more lucrative materials could make the recycling process far more attractive and effective. Currently plastics lose about 95 percent of their value as a material after a single use. Encouraging better collection and use of such waste is key to tackling the global plastic pollution problem.

Researchers have already developed mutant enzymes to break down the polyethylene terephthalate polymer used for drinks bottles into its basic units, terephthalic acid (TA). Scientists have now used bugs to convert TA into vanillin.

Vanillin is used widely in the food and cosmetics industries and is an important bulk chemical used to make pharmaceuticals, cleaning products and herbicides. Global demand is growing and in 2018 was 37,000 metric tons, far exceeding the supply from natural vanilla beans. About 85 percent of vanillin is currently synthesized from chemicals derived from fossil fuels.

Joanna Sadler, of the University of Edinburgh, who conducted the new work, said: “This is the first example of using a biological system to upcycle plastic waste into a valuable industrial chemical and it has very exciting implications for the circular economy.”

Stephen Wallace, also of the University of Edinburgh, said: “Our work challenges the perception of plastic being a problematic waste and instead demonstrates its use as a new carbon resource from which high value products can be made.”

About 1 million plastic bottles are sold every minute around the world and just 14 percent are recycled. Currently even those bottles that are recycled can only be turned into opaque fibres for clothing or carpets.

The research, published in the journal Green Chemistry, used engineered E coli bacteria to transform TA into vanillin. The scientists warmed a microbial broth to 37 Celsius for a day, the same conditions as for brewing beer, Wallace said. This converted 79 percent of the TA into vanillin.

Next the scientists will further tweak the bacteria to increase the conversion rate further, he said: “We think we can do that pretty quickly. We have an amazing roboticised DNA assembly facility here.” They will also work on scaling up the process to convert larger amounts of plastic. Other valuable molecules could also be brewed from TA, such as some used in perfumes.

Ellis Crawford, of the Royal Society of Chemistry, said: “This is a really interesting use of microbial science to improve sustainability. Using microbes to turn waste plastics, which are harmful to the environment, into an important commodity is a beautiful demonstration of green chemistry.”

Recent research showed bottles are the second most common type of plastic pollution in the oceans, after plastic bags. In 2018, scientists accidentally created a mutant enzyme that breaks down plastic bottles, and subsequent work produced a super-enzyme that eats plastic bottles even faster.

More Mother Jones reporting on Climate Desk

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with the Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with the Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate