It looks like we might finally have a solution to break down incredibly resistant plastic. There are trillion of polyethylene plastic bags used every year throughout the world. But scientists have reported in Current Biology that a caterpillar commonly known as a wax worm might be our hero here.
Federica Bertocchini of the Institute of Biomedicine and Biotechnology of Cantabria in Spain said that the larva of Galleria mellonella was able to biodegrade one of the toughest, most resilient, and most used plastics-polyethylene. A previous study also shows that Plodia interpunctella wax worms, the larvae of Indian meal moths, can also digest plastic.
Bertocchini and her colleagues discovered by accident, after noticing that plastic bags containing wax worms became riddled with holes. When it was further studied, it showed that the worms might do damage to a plastic bag in less than an hour.
After 12 hours, all that munching of plastic leads to an obvious reduction in plastic mass. Researchers showed that the wax worms were not only ingesting the plastic. They were also chemically transforming the polyethylene into ethylene glycol.
Even though plastic is not one of their regular diets, it is suspected that their ability is a byproduct of their natural habits. Wax moths usually lay their eggs inside beehives. The worms hatch and grow on beeswax, which is composed of a highly diverse mixture of lipid compounds. The researchers say the molecular details of wax biodegradation requires further investigation, but digesting beeswax and polyethylene likely involves breaking down similar types of chemical bonds.
“Wax is a polymer, a sort of ‘natural plastic,’ and has a chemical structure not dissimilar to polyethylene,” Bertocchini says.
As we know the molecular basis, the researchers say it might be used to devise a biotechnological solution for managing polyethylene waste. They will continue to explore the process in search of such a strategy.
“We are planning to implement this finding into a viable way to get rid of plastic waste, working towards a solution to save our oceans, rivers, and all the environment from the unavoidable consequences of plastic accumulation,” Bertocchini says. “However,” she adds, “we should not feel justified to dump polyethylene deliberately in our environment just because we now know how to bio-degrade it.”