Scientists from the University of Edinburgh have engineered genetically modified Escherichia coli bacteria to convert terephthalic acid, derived from PET plastic waste, into paracetamol. This technique marks an advancement in sustainable recycling methods and the production of medicines.
The research team, led by Professor Stephen Wallace, utilized components from used PET plastic bottles to induce a chemical reaction in a strain of E. coli bacteria. "This study shows that PET plastic is not just waste or a material doomed to become more plastic. Microorganisms can convert it into new, valuable products, including some with potential to treat diseases," said Professor Stephen Wallace, according to Phys.org.
The researchers employed a fermentation process, similar to brewing beer, to accelerate the conversion of industrial PET waste into paracetamol in less than 24 hours. The process was carried out at room temperature and produced virtually no carbon emissions, proving that paracetamol can be produced sustainably.
Paracetamol is traditionally made from dwindling supplies of fossil fuels, including crude oil, and the production involves techniques that are low-cost but quite polluting. The new method not only helps reduce plastic pollution but also curbs reliance on fossil fuels currently used to produce paracetamol, making it a more sustainable strategy.
Plastic waste is becoming an increasingly serious problem, with over 350 million tons generated annually, much of it from PET, which harms the environment and human health. Although PET recycling is possible, existing processes often produce new plastics or low-value materials that continue to contribute to plastic pollution, with high energy and environmental costs.
In their study, the team employed a chemical reaction known as the Lossen rearrangement, which had until now only been observed in test tubes and had not been induced in living cells. The reaction occurred spontaneously in the presence of E. coli, with phosphate within the bacterial cells catalyzing the process without the need for harsh laboratory conditions.
"By merging chemistry and biology in this way for the first time, we can make paracetamol more sustainably and clean up plastic waste from the environment at the same time," said Wallace, as reported by Phys.org.
The research was funded by the British agency EPSRC and the biopharmaceutical company AstraZeneca, with support from Edinburgh Innovations, the university's technology transfer center. "Engineering biology offers immense potential to disrupt our reliance on fossil fuels, build a circular economy, and create sustainable chemicals and materials, and we would invite potential collaborators to get in touch," said Ian Hatch, director of consultancy at Edinburgh Innovations, according to Phys.org.
While the scientists acknowledge that much development is necessary before the process can be used in industries, they believe this finding represents a milestone in the integration of synthetic chemistry into living organisms and marks the beginning of a new era in the production of sustainable drugs.
"Although it's still early days, this could mark part of a broader shift toward more sustainable, biology-based manufacturing practices," Wallace noted.
The study published in Nature Chemistry demonstrates the potential of metabolic engineering in plastic recycling and shows the production of paracetamol from plastic waste using a more sustainable strategy, leaving virtually no carbon emissions.
This approach demonstrates how traditional chemistry can work with engineering biology to create living microbial factories capable of producing sustainable chemicals while also reducing waste, greenhouse gas emissions, and reliance on fossil fuels.
The researchers enhanced and reproduced the Lossen rearrangement capability within bacteria using only the microbial cells themselves and without resorting to complex laboratory catalysts. All of this occurred without the need for heavy metals, extreme heat, or artificial catalysts; phosphate alone was sufficient to make the reaction happen inside the living cells.
The team modified the common bacterium in the laboratory to degrade PET plastic bottles to obtain terephthalic acid, which is in turn converted into paracetamol. The conversion was achieved with an efficiency of 90%, which increased to 92% under optimized conditions.
The researchers believe that developing new methods to recycle plastic waste, such as using metabolic engineering to exploit chemical reactions in cells, is a priority for the future.
"What excites me most about our work is that we have shown a new and more ecological way to manufacture this global medicine, using bacterial fermentation instead of fossil fuels," Wallace stated.
Produced with the assistance of a news-analysis system.