Scientists use bacteria to convert plastic into paracetamol

A bacterium eats a plastic bottle and, once the waste is inside its structure, the cell ferments it as if it were beer and turns it into paracetamol. That’s a simplified summary of a scientific study — published Monday in the journal Nature — in which classical chemistry is used in a “completely new” way for the first time, according to lead author Stephen Wallace. He explains the breakthrough: “By using living microbes, we performed sophisticated chemical transformations, which could open up new, greener, and more sustainable ways to produce valuable materials, such as medicines, from waste.”

Wallace and his research team at the University of Edinburgh managed to trigger a natural process within a living Escherichia coli bacterium — a chemical reaction that until now had only been observed in test tubes. Specifically, they achieved the transformation of acid-derived molecules into key compounds used in drug production — such as paracetamol — through a process known as the Lossen rearrangement. The team succeeded in reproducing this reaction inside bacteria using only the microbes themselves, without relying on complex laboratory catalysts.

“The interesting thing is that we didn’t have to teach the bacteria how to do the reaction: the trick was realizing they already had the tools and just had to be guided,” Wallace explains.

Within their cells, bacteria naturally contain phosphate, which can activate the chemical catalysis the researchers were targeting. “What we did was use synthetic biology to build new biological pathways inside the bacteria,” says Wallace. “These pathways guide the cell’s chemistry toward producing the specific compound we wanted. In this case, a drug.”

So, instead of forcing bacteria to do something entirely new, the scientists simply gave them the right blueprint and let their internal chemistry do the rest.

Plastic comes into play at the very start of the process. PET — widely used in beverage containers — is broken down into one of its basic components, which is then converted into a molecule capable of triggering the chemical reaction inside the bacteria. From there, the microorganisms transform that molecule into a key ingredient, and finally into paracetamol.

“Based on what we’ve seen, it’s highly likely that many — or even most — bacteria can perform these kinds of transmutations. This opens up a whole new way of thinking about how we might use microbes as tiny chemical factories,” says Wallace.

Emission-free factories

These miniature factories, moreover, operate at room temperature and produce no carbon emissions — a crucial difference from traditional paracetamol production. As Wallace points out: “It’s fascinating that very few people know that the paracetamol they take begins its life as petroleum.” He adds: “What excites me most about our work is that we’ve demonstrated a new, greener way to manufacture this global medicine, using bacterial fermentation instead of fossil fuels.”

Although it’s still early days, this could mark part of a broader shift toward more sustainable, biology-based manufacturing practices, both in the pharmaceutical industry and in plastic recycling. “After all, waste is just carbon, and microbes love carbon. Instead of releasing waste into the atmosphere through incineration or landfilling it, we can put it to work,” says Wallace.

So far, the team has only managed to produce and extract small quantities of paracetamol. The next step is to scale up production — and eventually, the product would need to undergo rigorous testing: “Human trials are a completely different step, and rightly so. Any drug intended for commercial use must go through rigorous safety and regulatory testing, which takes time and close oversight,” explains Wallace.

So, although the scientists believe their work shows “exciting potential,” there is still a long way to go before this microbe-made paracetamol is ready for medical use.

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