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An Accidental Discovery Could Solve Earth's Plastic Waste Problem
Scientists find a surprising way to biodegrade plastic at an impressively fast rate.
Scientists might have stumbled upon an unexpected way to solve pollution from plastics. A caterpillar bred to be fishing bait is apparently able to biodegrade polyethylene - a commonly used plastic found in shopping bags. With people using around a trillion plastic bags every year, and with up to 40% of them ending up in landfills, this could be a very significant discovery.
The wax worm caterpillar that eats plastic is the larvae of the common insect Galleria mellonella, aka greater wax moth.
The team working on the study, published in the journal Current Biology, included Federica Bertocchini from the Spanish Institute of Biomedicine and Biotechnology of Cantabria, and biochemists Paolo Bombelli and Christopher Howe from the University of Cambridge in the UK.
The discovery was made by sheer chance when Bertocchini, who is an amateur beekeeper, removed the worms living in a beehive as parasites - a common problem across Europe. She collected them in a plastic bag and soon noticed holes throughout the bag. The worms ate their way out!
This prompted a timed experiment by her team, who placed about a hundred such worms in a plastic bag from a UK supermarket. They realized that the holes started to materialize just after 40 minutes, continuing to develop at a very fast rate compared to other attempts to biodegrade plastics. The worms reduced the plastic mass by 92 mg in 12 hours, in contrast to the rate of 0.13 mg per day maintained by bacteria, recently utilized in a similar effort.
Here's a video of the worms in action:
After digesting the plastic, the worms left behind ethylene glycol, the key ingredient in antifreeze.
Plastic is hard to break down, taking from 100 to 400 years to degrade naturally, and has been blamed for adversely affecting the environment. The scientists propose that digesting beeswax requires the worms to break down chemical bonds in a process similar to breaking down polyethylene.
"The caterpillars are not just eating the plastic without modifying its chemical make-up. We showed that the polymer chains in polyethylene plastic are actually broken by the wax worms,“ said the study’s first author Paolo Bombelli. "The caterpillar produces something that breaks the chemical bond, perhaps in its salivary glands or a symbiotic bacteria in its gut. The next steps for us will be to try and identify the molecular processes in this reaction and see if we can isolate the enzyme responsible," he added.
If the scientists can isolate the enzyme used by the worms to break down plastic, they will look to turn their findings into an industrial-scale solution for polyethylene waste.
"If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable,” said Bombelli. “This discovery could be an important tool for helping to get rid of the polyethylene plastic waste accumulated in landfill sites and oceans.”
"You dream about these kinds of moments when you're a kid," said lead paleontologist David Schmidt.
- The triceratops skull was first discovered in 2019, but was excavated over the summer of 2020.
- It was discovered in the South Dakota Badlands, an area where the Triceratops roamed some 66 million years ago.
- Studying dinosaurs helps scientists better understand the evolution of all life on Earth.
Credit: David Schmidt / Westminster College<p style="margin-left: 20px;">"We had to be really careful," Schmidt told St. Louis Public Radio. "We couldn't disturb anything at all, because at that point, it was under law enforcement investigation. They were telling us, 'Don't even make footprints,' and I was thinking, 'How are we supposed to do that?'"</p><p>Another difficulty was the mammoth size of the skull: about 7 feet long and more than 3,000 pounds. (For context, the largest triceratops skull ever unearthed was about <a href="https://www.tandfonline.com/doi/abs/10.1080/02724634.2010.483632" target="_blank">8.2 feet long</a>.) The skull of Schmidt's dinosaur was likely a <em>Triceratops prorsus, </em>one of two species of triceratops that roamed what's now North America about 66 million years ago.</p>
Credit: David Schmidt / Westminster College<p>The triceratops was an herbivore, but it was also a favorite meal of the T<em>yrannosaurus rex</em>. That probably explains why the Dakotas contain many scattered triceratops bone fragments, and, less commonly, complete bones and skulls. In summer 2019, for example, a separate team on a dig in North Dakota made <a href="https://www.nytimes.com/2019/07/26/science/triceratops-skull-65-million-years-old.html" target="_blank">headlines</a> after unearthing a complete triceratops skull that measured five feet in length.</p><p>Michael Kjelland, a biology professor who participated in that excavation, said digging up the dinosaur was like completing a "multi-piece, 3-D jigsaw puzzle" that required "engineering that rivaled SpaceX," he jokingly told the <a href="https://www.nytimes.com/2019/07/26/science/triceratops-skull-65-million-years-old.html" target="_blank">New York Times</a>.</p>
Morrison Formation in Colorado
James St. John via Flickr
|Credit: Nobu Tamura/Wikimedia Commons|
The world's 10 most affected countries are spending up to 59% of their GDP on the effects of violence.
- Conflict and violence cost the world more than $14 trillion a year.
- That's the equivalent of $5 a day for every person on the planet.
- Research shows that peace brings prosperity, lower inflation and more jobs.
- Just a 2% reduction in conflict would free up as much money as the global aid budget.
- Report urges governments to improve peacefulness, especially amid COVID-19.
The lush biodiversity of South America's rainforests is rooted in one of the most cataclysmic events that ever struck Earth.
- One especially mysterious thing about the asteroid impact, which killed the dinosaurs, is how it transformed Earth's tropical rainforests.
- A recent study analyzed ancient fossils collected in modern-day Colombia to determine how tropical rainforests changed after the bolide impact.
- The results highlight how nature is able to recover from cataclysmic events, though it may take millions of years.