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Biology

What a relief! Microbes transform plastic waste into paracetamol

By ScientifiCult 23 June 2025

What a relief! Microbes transform plastic waste into paracetamol

Paracetamol production could be revolutionised by the discovery that a common bacterium can turn everyday plastic waste into the painkiller, a study reveals.

The new method leaves virtually no carbon emissions and is more sustainable than the current production of the medicine, researchers say.

Paracetamol is traditionally made from dwindling supplies of fossil fuels including crude oil.

Thousands of tons of fossil fuels are used annually to power the factories that produce the painkiller, alongside other medicines and chemicals – making a significant contribution to climate change, experts say.

The breakthrough addresses the urgent need to recycle a widely used plastic known as polyethylene terephthalate (PET), which ultimately ends up in landfill or polluting oceans.

The strong, lightweight plastic is used for water bottles and food packaging, and creates more than 350 million tons of waste annually, causing serious environmental damage worldwide.

PET recycling is possible, but existing processes create products that continue to contribute to plastic pollution worldwide, researchers say.

plastic into paracetamol: A PhD student checks the growth of a culture of Escherichia coli in the Wallace Lab. Photo Credits: University of Edinburgh. — A PhD student checks the growth of a culture of Escherichia coli in the Wallace Lab. Photo Credits: University of Edinburgh.

A team of scientists from the University of Edinburgh’s Wallace Lab used genetically reprogrammed E. coli, a harmless bacterium, to transform a molecule derived from PET known as terephthalic acid into the active ingredient of paracetamol.

Researchers used a fermentation process, similar to the one used in brewing beer, to accelerate the conversion from industrial PET waste into paracetamol in less than 24 hours.

The new technique was carried out at room temperature and created virtually no carbon emissions, proving that paracetamol can be produced sustainably.

Further development is needed before it can be produced at commercial levels, the team says.

Some 90 per cent of the product made from reacting terephthalic acid with genetically reprogrammed E. coli was paracetamol.

The University of Edinburgh is a world-leader in engineering biology, which uses engineering principles to harness biological processes to create new products and services. The University hosts the largest and most comprehensive group of researchers in the country.

Experts say this new 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 research, published in Nature Chemistry, was funded by an EPSRC CASE award and biopharmaceutical company AstraZeneca, supported by Edinburgh Innovations (EI), the University’s commercialisation service.

Professor Stephen Wallace, lead author, UKRI Future Leaders Fellow and Chair of Chemical Biotechnology, School of Biological Sciences, University of Edinburgh, said:

“This work demonstrates that PET plastic isn’t just waste or a material destined to become more plastic – it can be transformed by microorganisms into valuable new products, including those with potential for treating disease.”

Professor Stephen Wallace. Photo Credits: Edinburgh Innovations and Maverick Photography

Ian Hatch, Head of Consultancy at EI, said: “We are bringing in exceptional companies like AstraZeneca to work with Stephen and others at the University to translate these cutting-edge discoveries into world-changing innovations.

“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.”

Bibliographic information:

Johnson, N.W., Valenzuela-Ortega, M., Thorpe, T.W. et al., A biocompatible Lossen rearrangement in Escherichia coli, Nat. Chem. (2025), DOI: https://doi.org/10.1038/s41557-025-01845-5

Press release from the University of Edinburgh

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Astronomy

Hubble finds that ageing brown dwarfs grow lonely

By ScientifiCult 21 March 2024

Hubble finds that ageing brown dwarfs grow lonely: for the ones that were once paired, that’s a relationship that doesn’t last long

It takes two to tango, but in the case of brown dwarfs that were once paired as binary systems, that relationship doesn’t last for very long, according to a recent survey using the NASA/ESA Hubble Space Telescope.

This artist’s representation shows a brown dwarf, an object more massive than a planet but smaller than a star. The dwarf is a cherry-red sphere. It has horizontal stripes of various shades of red that are cloud bands. In the dark background there are myriad stars that are inside our Milky Way galaxy. — This is an artist’s representation of a brown dwarf. This class of object is too large to be a planet (and did not form in the same way), but is too small to be a star because it cannot sustain nuclear fusion, since it is less massive than even the smallest stars. A brown dwarf is likely to be marked by wind-driven horizontal bands of thick clouds that may alternate with relatively cloud-free bands, giving the object a striped appearance. Whirling storm systems as big as terrestrial continents, or even small planets, might exist.
The name ‘brown dwarf’ is actually a misnomer because the object would typically appear red to the naked eye. It is brightest in infrared light. Many brown dwarfs have binary companions. But as they age, the binary system drifts apart and each dwarf goes its separate way, according to a recent Hubble Space Telescope study.
The background stars in this illustration are a science visualisation assembled from the Gaia spacecraft star catalogue. The synthesised stars are accurate in terms of position, brightness, and colour. Because this is not an image of the Milky Way, missing are glowing nebulae and dark dust clouds.
Credit: NASA, ESA, J. Olmsted (STScI)

Brown dwarfs are interstellar objects larger than Jupiter but smaller than the lowest-mass stars. Like stars, they collapse out of a cloud of gas and dust but do not have enough mass to sustain the fusion of hydrogen like a normal star.

Like stars, brown dwarfs can be born in pairs and orbit about each other. A Hubble Space Telescope survey has found that the older a brown dwarf is, the less likely it is to have a companion dwarf. This implies that a binary pair of dwarfs is so weakly linked by gravity that they drift apart over a few hundred million years as a result of the pull of bypassing stars. Call them the lonely hearts of the cosmos.

Hubble can detect binaries as close to each other as 480 million kilometres — the approximate separation between our Sun and the asteroid belt. But the astronomers who carried out the survey didn’t find any binary pairs in a sample of brown dwarfs in the solar neighbourhood.

“Our survey confirms that widely separated companions are extremely rare among the lowest-mass and coldest isolated brown dwarfs, even though binary brown dwarfs are observed at younger ages. This suggests that such systems do not survive over time,” said lead author Clémence Fontanive of the Trottier Institute for Research on Exoplanets, University of Montreal, Canada.

In a similar survey Fontanive conducted a couple of years ago, Hubble looked at extremely young brown dwarfs and some had binary companions, confirming that star-forming mechanisms do produce binary pairs among low-mass brown dwarfs. The lack of binary companions for older brown dwarfs suggests that some may have started out as binaries, but parted ways over time.

The new Hubble findings further support the theory that brown dwarfs are born the same way as stars, through the gravitational collapse of a cloud of molecular hydrogen. The difference is that they do not have enough mass to sustain nuclear fusion of hydrogen for generating energy, whereas stars do. More than half of the stars in our galaxy have a companion star that resulted from these formation processes, with more massive stars more commonly found in binary systems. “The motivation for the study was really to see how low in mass the trends seen among multiple star systems hold up,” said Fontanive.

“Our Hubble survey offers direct evidence that these binaries that we observe when they’re young are unlikely to survive to old ages, they’re likely going to get disrupted. When they’re young, they’re part of a molecular cloud, and then as they age the cloud disperses. As that happens, things start moving around and stars pass by each other. Because brown dwarfs are so light, the gravitational hold tying wide binary pairs is very weak, and bypassing stars can easily tear these binaries apart,” said Fontanive.

The team selected a sample of brown dwarfs previously identified by NASA’s Wide-Field Infrared Survey Explorer. It sampled some of the coldest and lowest-mass old brown dwarfs in the solar neighbourhood. These old brown dwarfs are so cool (a few hundred degrees warmer than Jupiter in most cases) that their atmospheres contain water vapour that condensed out.

To find the coolest companions, the team used two different near-infrared filters, one in which cold brown dwarfs are bright, and another covering specific wavelengths where they appear very faint as a result of water absorption in their atmospheres.

“Most stars have friends – whether that is a binary companion or exoplanets,” added team member Beth Biller of the University of Edinburgh in the United Kingdom. “This survey really demonstrates that the same is not true for brown dwarfs. After a brief period early in their lifespans, most brown dwarfs remain single for the rest of their very long existence.”

“This is the best observational evidence to date that brown dwarf pairs drift apart over time,” said Fontanive. “We could not have done this kind of survey and confirmed earlier models without Hubble’s sharp vision and sensitivity.”

Press release from ESA Hubble.

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Astronomy

Webb spots swirling, gritty clouds on VHS 1256 b, a remote planet

By ScientifiCult 22 March 2023

Webb spots swirling, gritty clouds on VHS 1256 b, a remote planet

Researchers observing with the NASA/ESA/CSA James Webb Space Telescope have pinpointed silicate cloud features in a distant planet’s atmosphere. The atmosphere is constantly rising, mixing, and moving during its 22-hour day, bringing hotter material up and pushing colder material down. The resulting brightness changes are so dramatic that it is the most variable planetary-mass object known to date. The science team also made extraordinarily clear detections of water, methane and carbon monoxide with Webb’s data, and found evidence of carbon dioxide. This is the largest number of molecules ever identified all at once on a planet outside our Solar System.

Exoplanet VHS 1256 b — This illustration conceptualises the swirling clouds identified by the James Webb Space Telescope in the atmosphere of the exoplanet VHS 1256 b. The planet is about 40 light-years away and orbits two stars that are locked in their own tight rotation. Its clouds, which are filled with silicate dust, are constantly rising, mixing, and moving during its 22-hour day.
Credit:
NASA, ESA, CSA, J. Olmsted (STScI)

Catalogued as VHS 1256 b, the planet is about 40 light-years away and orbits not one, but two stars over a 10 000-year period.

“VHS 1256 b is about four times farther from its stars than Pluto is from our Sun, which makes it a great target for Webb,” said science team lead Brittany Miles of the University of Arizona. “That means the planet’s light is not mixed with light from its stars.” Higher up in its atmosphere, where the silicate clouds are churning, temperatures reach a scorching 830 degrees Celsius.

Within those clouds, Webb detected both larger and smaller silicate dust grains, which are shown on a spectrum.

“The finer silicate grains in its atmosphere may be more like tiny particles in smoke,” noted co-author Beth Biller of the University of Edinburgh in the United Kingdom. “The larger grains might be more like very hot, very small sand particles.”

VHS 1256 b has low gravity compared to more massive brown dwarfs [1], which means that its silicate clouds can appear and remain higher in its atmosphere where Webb can detect them. Another reason its skies are so turbulent is the planet’s age. In astronomical terms, it’s quite young. Only 150 million years have passed since it formed — and it will continue to change and cool over billions of years.

In many ways, the team considers these findings to be the first ‘coins’ pulled out of a spectrum that researchers view as a treasure chest of data. In many ways, they’ve only begun identifying its contents.

“We’ve identified silicates, but a better understanding of which grain sizes and shapes match specific types of clouds is going to take a lot of additional work,” Miles said. “This is not the final word on this planet — it is the beginning of a large-scale modelling effort to fit Webb’s complex data.”

Although all of the features the team observed have been spotted on other planets elsewhere in the Milky Way by other telescopes, other research teams typically identified only one at a time.

“No other telescope has identified so many features at once for a single target,” said co-author Andrew Skemer of the University of California, Santa Cruz. “We’re seeing a lot of molecules in a single spectrum from Webb that detail the planet’s dynamic cloud and weather systems.”

The team came to these conclusions by analysing data known as spectra gathered by two instruments aboard Webb, the Near-Infrared Spectrograph (NIRSpec) and the Mid-Infrared Instrument (MIRI). Since the planet orbits at such a great distance from its stars, the researchers were able to observe it directly, rather than using the transit technique [2] or a coronagraph [3] to take this data.

There will be plenty more to learn about VHS 1256 b in the months and years to come as this team — and others — continue to sift through Webb’s high-resolution infrared data. “There’s a huge return on a very modest amount of telescope time,” Biller added. “With only a few hours of observations, we have what feels like unending potential for additional discoveries.”

What might become of this planet billions of years from now? Since it’s so far from its stars, it will become colder over time, and its skies may transition from cloudy to clear.

The researchers observed VHS 1256 b as part of Webb’s Early Release Science program, which is designed to help transform the astronomical community’s ability to characterise planets and the discs from which they form.

The team’s paper, entitled “The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 Micron Spectrum of the Planetary-Mass Companion VHS 1256-1257 b,” will be published in The Astrophysical Journal Letters on 22 March.

Press release from ESA Webb.

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