Scientists have found that the caterpillars of wax moths have the ability to eat plastic shopping bags, suggesting a biodegradable solution to plastic pollution.
The wax worm, usually bred as fish bait, is a scourge of beehives across Europe, as the worms consume beeswax as their main diet and live as parasites in bee colonies.
A chance discovery occurred when Federica Bertocchini, a researcher at the Spanish National Research Council and an amateur beekeeper, was removing wax worms from the honeycombs in her hives. She put the worms in a plastic shopping bag that later became riddled with holes.
The discovery led Bertocchini and other scientists at Cambridge University to conduct further research.
Polyethylene, one of the toughest and most commonly used plastics for making plastic bags and packaging, takes between 100 and 400 years to degrade in landfill sites.
By contrast, scientists in this study put 100 wax worms on a plastic shopping bag from a British supermarket. Holes started to appear after just 40 minutes, according to the study published in the journal Current Biology on Monday.
And after 12 hours, these wax worms devoured 92 milligrams of plastic mass from the bag.
The degradation rate using wax worms is more than 1,400 times faster than previous tests involving bacteria. The microbes could only biodegrade plastics at a rate of 0.13 milligram in a day, according to a separate study last year.
To confirm that the plastic bag was digested by some enzymes produced by the wax worm rather than it biting through the plastic bag, scientists smashed some of the wax worms and smeared them on polyethylene bags. Holes appeared again.
"The caterpillar produces something that breaks the chemical bond, perhaps in its salivary grands or a symbiotic bacteria in its gut," said Paolo Bombelli, a biochemist at Cambridge University and the first author of the study.
"If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable," Bombelli added.
The study provides new hope for scientists to work for a solution to plastic waste that chokes oceans and landfills.
"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 noted.
