A vanilla-scented solution to the world’s plastic crisis? Yes, please! A novel way of handling the problem might just have been discovered, and it smells (and tastes) like vanilla.

Research recently published in the journal Green Chemistry proposes a way of using bacteria to transform post-consumer plastic into vanillin, the compound which gives vanilla its delicious taste and smell. Not only does this present a sustainable way to reduce plastic waste, but it could also be a tasty opportunity to produce (and eat) more ice cream – win-win!

In the new research, conducted by a team at the University of Edinburgh, E. coli was genetically engineered to allow it to convert terephthalic acid – a molecule derived from polyethylene terephthalate (PET) – into vanillin. PET is a type of plastic, commonly used to make single-use plastic water bottles and clamshell packaging. It is derived from non-renewable materials, and current recycling methods only break it down into its constituent parts, one of which is terephthalic acid. These are then used to make either more PET, or second-generation plastic, therefore still contributing to plastic pollution. With around 50 million tonnes of PET waste being produced every year, it is imperative we find a more effective and sustainable method.

Enter, E. coli. They haven’t always had good press, but it seems the time has come for them to redeem themselves. The team put them to use and were able to achieve a 79 percent conversion of terephthalic acid to vanillin. They also demonstrated the process by converting an old plastic bottle into vanillin, by adding E. coli to the degraded plastic waste.

"This is the first example of using a biological system to upcycle plastic waste into a valuable industrial chemical and this has very exciting implications for the circular economy,” said Joanna Sadler, first author of the paper, in a statement. "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."

While the researchers claim the vanillin yielded is fit for human consumption, this is yet to be verified and further tests are required. However, there are more uses for vanillin than simply making ice cream or milkshakes. It is also used in the cosmetics industry and is an important bulk chemical, used in herbicides and cleaning products.

So we might not be making an ice cream sundae from a plastic bottle just yet, but this ingenious way to reduce PET waste could massively benefit the environment and address our current plastic problem. The promise of more ice cream is just the cherry on top.

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