As we all know, plastic waste is a growing problem. Around 80 million tons of polyethylene is produced each year around the world, and it takes more than a hundred years for this substance to degrade completely. Researchers are therefore looking to nature to find ways of boosting the speed at which we can degrade this material.
A research team from Europe has accidentally found out that a common caterpillar is capable of breaking down the plastic found in shopping bags and other polyethylene-based products. Call it a happy accident, now researchers want to use the bugs to develop a quick way of breaking down the polyethylene material that is found in many non-biodegradable plastics.
“Our study is the first scientific work to show that this species eats plastic with the chemical depolymerisation of polyethylene,” one of the researchers, Federica Bertocchini of the Spanish National Research Council, said.
These creatures might be digesting polyethylene in the same way as they digest beeswax, the scientists suggest, using special enzymes in their gut and breaking down similar types of chemical bonds along the way.
To find out what was going on, Federica Bertocchini decided to investigate further and recruited biochemist Paolo Bombelli from the University of Cambridge to help her out. The researchers first exposed 100 caterpillars to a plastic polyethylene supermarket bag. After just 40 minutes, holes began to appear in the bag, and after 12 hours the larvae had managed to reduce the amount of plastic by as much as 92 milligrams.
In subsequent tests, the team ground some of the caterpillars into a paste and spread a thin layer of it onto a polyethylene film. Within 14 hours, the substance had broken down 13 percent of the plastic.
“This discovery could be an important tool for helping to get rid of the polyethylene plastic waste accumulated in landfill sites and oceans.”, said biochemist Paolo Bombelli.
Nature may have provided us with an answer to our plastic problem, but we still need to figure out how these creatures would do it if we had to use them on an industrial scale.“The caterpillar produces something that breaks the chemical bond,” said Bombelli. “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.”