Plastic may have finally met its match in a caterpillar. Scientists have found that wax moth larvae easily chew through plastic material called polyethylene, changing it back into a compound that can be made useful for other products.
Research shows that the wax moth, an insect that lives in bee hives and other places, can happily eat plastic, The Los Angeles Times reports. This could posit a solution to the growing problem of plastic waste.
The discovery was accidentally made by Federica Bertocchini, a developmental biologist at Institute of Biomedicine and Biotechnology of Cantabria in Spain and a beekeeper. He noticed that when the hives were wrapped in plastic, the moth larvae appeared to break the material down.
To find out, Bertocchini and a team set wax worms on a polyethylene film, and were surprised to discover that holes appeared after just 40 minutes. That’s an estimated rate of 2.2 holes per worm per hour. When the researchers placed the caterpillars in a plastic shopping bag, the worms ate 92 milligrams in just 12 hours.
The researchers thought that the wax worms could simply be eating rather than digesting the plastic material, so they made a slurry of some worms and smeared them on polyethylene films. In 14 hours, 13% of the polyethylene was gone, which equates to 0.23 milligrams per square centimeter.
Upon examining the remains of the plastic film, the researchers found indications of ethylene glycol, which means the caterpillar slurry had broken the plastic material down.
Christopher J. Howe, a biochemist at Cambridge University and co-author on the study, says the answer to why this is possible lies in the worms’ natural diet. He said it’s “probably because the beeswax in the hives is similar chemically to the plastic.”
The larvae have evolved to be able to break down the beeswax, and can break down plastic as well, given the chemical similarity.
The next step is to conduct further research to see if the worms can really be used to break down waste polyethylene. “In the long term we’d like to use this as a basis for breaking down waste polyethylene — but there are many hurdles to be overcome in scaling the process up,” Howe said. “We would probably try to find the gene(s) for the enzyme(s) that are responsible, and use the gene to make lots of the enzyme in a biotechnological process rather than growing large numbers of the caterpillars.”
The study was published in Current Biology.