Scientists convert used plastic bottles into vanilla flavouring

Researchers have found a way to turn plastic bottles into valuable vanilla flavoring using genetically engineered bacteria. This is the first time a useful chemical has been made from waste plastic. By converting plastic bottles into more valuable materials, recycling can become more efficient and appealing.

Plastic typically loses about 95% of its value after just one use, making it important to find better ways to collect and reuse waste plastic. Scientists have already created mutant enzymes to break down polyethylene terephthalate (PET), the plastic used in drink bottles, into its basic components. Now, they have used bacteria to turn one of those components, terephthalic acid (TA), into vanillin.

Vanillin is widely used in food and cosmetics, and it’s also an important ingredient in pharmaceuticals, cleaning products, and herbicides. Global demand for vanillin has been growing, with 37,000 tonnes used in 2018. This demand is much higher than the supply from natural vanilla beans, and about 85% of vanillin today is made from chemicals derived from fossil fuels.

Joanna Sadler from the University of Edinburgh, who led the research, said, “This is the first time a biological system has been used to turn plastic waste into a valuable industrial chemical. It has exciting potential for the circular economy.” Stephen Wallace, also from the University of Edinburgh, added, “This work challenges the view of plastic as waste and shows that it can be used to make high-value products.”

Every minute, about one million plastic bottles are sold worldwide, but only 14% are recycled. Even recycled bottles are usually turned into fibers for clothing or carpets. In their study, published in Green Chemistry, scientists used engineered E. coli bacteria to convert TA into vanillin, achieving a conversion rate of 79%.

Next, the scientists plan to improve the bacteria to increase the conversion rate and scale up the process to handle larger amounts of plastic. Other valuable chemicals, like those used in perfumes, could also be made from TA.