Solution to curb plastic pollution? A caterpillar that feeds on polythene!

New Delhi: Plastic waste is a menace that is the result of industrialization and to an extent, human activities, without realizing that it ends up affecting our health as well.

Plastic is considered inexpensive and durable, which is why it is most commonly used for packaging.

However, due to its slow degradation process, plastics can severely affect living organisms, especially marine life, through entanglement, direct ingestion of plastic waste, or through exposure to chemicals within plastics that cause interruptions in biological functions.

For humans, plastics can cause disruption of the thyroid hormone axis or hormone levels.

Because of this, environmentalists across the world have been promoting and encouraging everyone to do away with plastic use.

Now, scientists have found a way to combat plastic pollution by way of a commercially bred caterpillar that can quickly break down polythene bags and may help get rid of the plastic waste accumulating in landfill sites and oceans.

Researchers, including those from University of Cambridge in the UK, exposed around a hundred wax worms – the larvae of the common insect called greater wax moth – to a plastic bag.

Holes started to appear after just 40 minutes and after 12 hours there was a reduction in plastic mass of 92 milligramme (mg) from the bag, researchers said.

They conducted spectroscopic analysis to show the chemical bonds in the plastic were breaking.

The analysis showed that the worms – commonly used as fishing bait – transformed polyethylene into ethylene glycol.

To confirm it was not just the chewing mechanism of the caterpillars degrading the plastic, the team mashed up some of the worms and smeared them on polyethylene bags, with similar results.

"The caterpillars are not just eating the plastic without modifying its chemical make-up. We showed that the polymer chains in polyethylene plastic are actually broken by the wax worms," said Paolo Bombelli of University of Cambridge.

"The caterpillar produces something that breaks the chemical bond, perhaps in its salivary glands or a symbiotic bacteria in its gut," Bombelli said.

The degradation rate is extremely fast compared to other recent discoveries, such as bacteria reported to biodegrade some plastics at a rate of just 0.13 mg a day, researchers said.

"If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable," Bombelli said.

"This discovery could be an important tool for helping to get rid of the polyethylene plastic waste accumulated in landfill sites and oceans," he said.

The study was published in the journal Current Biology.

(With PTI inputs)