Can caterpillars save earth from plastic?

The humble caterpillar can be the answer to dealing with the growing mountains of plastic waste around the world, according to new research that shows it breaks down chemical bonds in plastic used for bags and packaging at unusually high speeds.

Scientists from the University of Cambridge and Spain say the discovery could lead to a biotechnological approach to polyethylene waste that chokes oceans and landfills. Plastic is usually highly resistant to breaking down, but nature may provide the answer.

The researchers found a caterpillar commercially bred for fishing bait has the ability to biodegrade polyethylene, one of the toughest and most used plastics, frequently found clogging landfill sites in the form of shopping bags.

The discovery is based on the wax worm, the larvae of the common insect Galleria mellonella, or greater wax moth, considered a scourge of beehives across Europe. In the wild, the worms live as parasites in bee colonies. Wax moths lay their eggs inside hives, where the worms hatch and grow on beeswax.

The chance discovery occurred when a member of the scientific team, Federica Bertocchini, an amateur bee-keeper, was removing the parasitic pests from honeycombs in her hives. The worms were temporarily kept in a typical plastic shopping bag that became riddled with holes.

Bertocchini, from the Institute of Biomedicine and Biotechnology of Cantabria, Spain, collaborated with colleagues Paolo Bombelli and Christopher Howe at the University of Cambridge’s department of biochemistry to conduct a timed experiment.

Around 100 wax worms were exposed to a plastic bag from a UK supermarket.

Holes started to appear after just 40 minutes, and after 12 hours, there was a reduction in plastic mass of 92 mg from the bag.

Scientists believe the degradation rate is extremely fast, compared to other recent discoveries, such as bacteria reported last year to biodegrade some plastics at a rate of 0.13 mg a day, a release from the University of Cambridge said.

“If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable,” said Bombelli, first author of the study published in the journal Current Biology.