Hungry, plastic-eating caterpillars could aid fight against pollution

26 Apr 2017

Plastic biodegraded by 10 worms in 30 minutes. Image: César Hernández/CSIC

The pollution created by non-biodegradable plastic bags is already a massive problem globally, but a newly discovered trait in a species of hungry caterpillar could change that.

The abundance of plastic pollution is causing a real problem, not only for the creatures we see around us, but throughout the entire ecosystem, to the point that many of us are unknowingly eating it, too.

While science has suggested a few answers as to how we could reverse situations such as the giant garbage patch of the Pacific Ocean, one possible solution to plastic bag pollution could be a species of hungry caterpillar.

According to Wired, this discovery was made by a researcher and amateur beekeeper from the Institute of Biomedicine and Biotechnology of Cantabria in Spain.

Typically, the wax worm is the bane of a beekeeper’s existence. When they enter a hive, they lay their eggs, creating wax moths that in turn lay more eggs within the beeswax.

When researcher Federica Bertocchini was removing wax worms from her own hive, she unknowingly unleashed the creatures throughout her home, revealing their hidden ability.

“I removed the worms, and put them in a plastic bag while I cleaned the panels,” she said.

“After finishing, I went back to the room where I had left the worms and I found they were everywhere. They had escaped from the bag even though it had been closed and when I checked, I saw the bag was full of holes.

“There was only one explanation: the worms had made the holes and escaped. This project began there and then.”

Wax worm eating plastic bag

A close-up of a wax worm next to biodegraded holes in a polyethylene plastic shopping bag from a UK supermarket, as used in the experiment. Image: Paolo Bombelli

Harnessing the enzyme

With this new knowledge, Bertocchini collaborated with the University of Cambridge to gather 100 wax worms together and place them on a plastic shopping bag.

Within a matter of 40 minutes, the worms had created holes in the bag and, after 12 hours, the weight of the plastic bag had reduced by 92g.

By comparison, plastic-eating bacteria previously studied as a potential natural solution to pollution could only eat 0.13g a day.

One interesting thing to note is that the worms aren’t physically eating the bags. In fact, they have an enzyme within their composition that offers enormous potential to be harnessed artificially.

“The caterpillar produces something that breaks the chemical bond, perhaps in its salivary glands or a symbiotic bacteria in its gut,” Bertocchini explained.

“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.”

Colm Gorey was a senior journalist with Silicon Republic