Goodbye to plastic waste? A bacteria converts it into paracetamol.

BarcelonaThe problem of plastic waste is growing: more and more are dumped into the world every year. more than 52 million tons. Therefore, it is urgent to develop sustainable ways to recycle this material, which has a huge impact on ecosystems, because plastics poison the oceans, kill birds and marine animals, and contaminate the food and water we consume. Now, researchers from the University of Edinburgh have made an unprecedented discovery that opens the door to a strategy for reusing this waste and transforming it into a useful product. Specifically, they have discovered in a study that a bacterium called Escherichia coli can convert a molecule from a plastic bottle into paracetamol. Despite the potential of the findings published in the journal Nature Chemistry On Monday, the authors clarify that more research is needed to determine whether it is a valid strategy in the fight against pollution.

Chemistry is everywhere. In plants and animals, the biochemical activity of cells is essential for life, but it is also present in synthetic compounds and materials that humans have created from chemical reactions, such as plastics. Historically, synthetic and biological chemistry have been considered separate fields, but in recent years, this trend has broken and there has been a delving into a field known as biocompatible chemistry, which involves introducing mutations into small organisms such as microbes to go beyond their biology and expand them. The authors of the research have done exactly this: they have discovered that a chemical reaction allows a modified bacterium to convert plastic waste into valuable compounds, such as a medicine.

This chemical reaction is known as the Lossen rearrangement: it can occur inside the cells of living beings and, in the case of the bacteria they used for the research, it occurs inside them thanks to the phosphate they have inside. The reaction produces an organic compound containing nitrogen that is essential for cellular metabolism. The authors used chemical methods to degrade a polyethylene terephthalate (PET) plastic bottle, obtained the molecule prior to the chemical reaction from the plastic, and demonstrated that the bacteria's cellular metabolism can transform it. They also found that this molecule can serve as a starting material to produce paracetamol, with 92% effectiveness. According to the authors, this is the first known case of this bacteria producing paracetamol from waste.

Limitations

However, although the results are very promising, the authors acknowledge that there are limitations that need further study. For example, there are practical challenges, such as potential toxic effects resulting from the chemical reaction, and the fact that the ability to convert plastics into other compounds can vary under industrial conditions. They also admit that the use of other microorganisms more suitable for industrial-scale production should be explored. From an economic perspective, they believe a full life-cycle assessment would be useful to compare this approach with other biocompatible chemistry strategies. And, looking to the future, they argue that similar chemical reactions should be investigated for recycling other types of plastics, as they could generate useful products beyond medicines.