Worms able to break down polyethylene plastic bags

Scientists believe the worm has enzymes in its saliva or gut that attack plastic's chemical bonds, in the same way they digest the wax found in hives. Study co-author Federica Bertocchini of the Spanish National Research Council happens to be an amateur beekeeper.

Placed in a plastic bag the grubs quickly leave it riddled with holes, in much the same way that a woollen jumper is attacked by clothes moth caterpillars.

Dr Paolo Bombelli, a member of the worldwide 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". But a colony of wax worms living in a landfill might cut down on the plastic bags that would otherwise sit there for who knows how long.

Bertocchini, from the Institute of Biomedicine and Biotechnology of Cantabria (CSIC), Spain, collaborated with colleagues Paolo Bombelli and Christopher Howe at the University of Cambridge's Department of Biochemistry to conduct a timed experiment.

Now, when a polyethylene film was left in direct contact with wax worms, in just 40 minutes, the worms had already made some holes in it.

Scientists say that the degradation rate is extremely fast compared to other recent discoveries, such as bacteria reported a year ago to biodegrade some plastics at a rate of just 0.13mg a day.

Polyethylene is largely used in packaging and accounts for 40% of the total demand for plastic products across Europe. But researchers reporting in Current Biology on April 24 may be on track to find a solution to plastic waste.

Each year, some eight million tonnes of waste plastic from around the world ends up in the sea.

The global plastic bag crisis could be solved by a waxworm capable of eating through the material at "uniquely high speeds", scientists have announced. Nowadays waste can be found everywhere, including in rivers and oceans.

The answer? Very. The team found the wax worms broke down polyethylene plastic bags faster than other recently-tested methods. They feed on beeswax, and their natural niche is the honeycomb; the moth lays its eggs inside the beehive, where the worms grow to their pupa stage, eating beeswax. After closer inspection, it became clear that the holes weren't just the result of the caterpillars attempting to chew their way to freedom.

Instead of breeding horse-sized caterpillars to digest plastic, though, researchers plan to figure out just what exactly in the caterpillar - be it the salivary glands or a symbiotic bacteria - is breaking down the plastic.

"We showed that the polymer chains in polyethylene plastic are actually broken by the wax worms, ".

The next step in their research is to figure out what kind of enzyme or enzymes the caterpillar is producing to break down the plastic.

"We're excited by what we've seen so far, but the precise molecular mechanism remains a mystery".

  • Leroy Wright