The Press and Journal (Aberdeen and Aberdeenshire)
Moth larvae could eat into world’s plastic waste pile
Science: Researcher’s chance discovery could offer answer to pollution
A moth that prefers plastic to pullovers could help solve the problem of discarded shopping bags and packaging, researchers believe.
The larvae of the greater wax moth normally thrive on beeswax, making them a hated enemy of bee keepers across Europe. But a chance discovery has shown that they will also happily munch on plastic.
Placed in a plastic bag the grubs quickly leave it riddled with holes, in much the same way a woollen jumper is attacked by clothes moth caterpillars.
Understanding how the larvae eat plastic could provide a biotechnological method of disposing of bags and packaging, a major source of land and sea pollution, say scientists.
“Nowadays waste can be found everywhere”
Dr Paolo Bombelli, a member of the international team from Cambridge University, said: “If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable.
“This discovery could be an important tool for helping to get rid of the polyethylene plastic waste accumulated in landfill sites and oceans.”
The caterpillars, known as “wax worms”, are commercially bred for fishing bait and in the wild live as parasites in bee colonies.
A member of the research team from Spain, who happens to keeps bees, spotted their penchant for plastic while removing the pests from her hives.
Dr Federica Bertocchini, from the Institute of Biomedicine and Biotechnology of Cantabria in Santander, placed the larvae in a plastic shopping bag and later found it was full of holes.
In a follow-up test conducted in Cambridge, 100 wax worms were let loose on a plastic bag from the British supermarket. Holes began to appear after just 40 minutes, and over a period of 12 hours 92mg of plastic was consumed.
The caterpillars worked much faster than bacteria, which in previous experiments took a day to biodegrade just 0.13mg of plastic.
Polyethylene is largely used in packaging and accounts for 40% of the total demand for plastic products across Europe.
Up to 38% of discarded plastic in Europe is buried in landfill sites. In the oceans, plastic waste breaks down into small particles which pose a serious health risk to the fish that ingest them. Each year, some eight million tonnes of waste plastic from around the world ends up in the sea.
Dr Bertocchini said: “Plastic is a global problem. Nowadays waste can be found everywhere, including in rivers and oceans.”
Beeswax consists of fatty compounds with a chainlike chemical structure similar to that of polyethylene, said the scientists.
The wax worm larvae are thought to digest beeswax and plastic in much the same way, by breaking down their chemical bonds.