Quite by chance, researchers recently discovered that the greater wax moth caterpillar – known as a pest in Europe that eats beeswax from honeycombs – is able to biodegrade polyethylene, the material used in plastic shopping bags.
This fortunate discovery came about after scientist and amateur beekeeper Federica Bertocchini of Spain’s IBBTEC institute picked some of the parasitic caterpillars out of her beehives and out them into a plastic bag. She later saw that the bag was hole-ridden because the critters had eaten their way out, and decided to study the wax worms further, with the help of researchers from the University of Cambridge’s biochemistry department.
The team placed a hundred of the bugs near a plastic bag and found that holes began appearing after just 40 minutes. After 12 hours, plastic mass was reduced by 92 milligrams. They further tested whether it was the chewing mechanism of the caterpillars that was degrading the plastic by mashing up some of the worms and smearing the paste onto the bags. However, the bags broke down with similar results, implying that the body of the wax moth caterpillar itself contains chemicals responsible for degrading polyethylene.
“The caterpillar produces something that breaks the chemical bond, perhaps in its salivary glands or a symbiotic bacteria in its gut,” Cambridge researcher and study author Paolo Bombelli said. “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. If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable.”
Polyethylene makes up around 40% of plastic products being made today, including the trillion plastic bags used every year around the world. Bombelli noted: “This discovery could be an important tool for helping to get rid of the polyethylene plastic waste accumulated in landfill sites and oceans.”
The team published their study in Current Biology.
Source: Chow, Lorraine. “This Tiny Caterpillar Could Help Solve the World’s Plastic Crisis.” EcoWatch. 25 April 2017.