Hungry caterpillar the new sidekick for plastics recyclers?

Spain – Polyethylene (PE) and polypropylene (PP) represent around 92% of total plastic production, while more than a trillion plastic bags are used every single year. Recycling this incredible volume of materials is quite a challenge, researchers have acknowledged. They propose a most unlikely solution to the growing waste problem; caterpillars.

It is a fact that plastics are largely resistant to biodegradation. However, a happy accident showed that moth caterpillars can quite easily eat themselves out of a plastic bag, so Paolo Bombelli, Christopher J. Howe and Federica Bertocchini (University of Cambridge & Spanish National Research Council) have discovered.

Lab tests showed that leaving a PE film in direct contact with a group of the larvae, also called wax worms, resulted in notable holes appearing after only 40 minutes. The results for similar when exposing the wax worms to a commercial PE shopping bag; after around 12 hours, there was a mass loss of 92 mg, and a 13% mass loss after 14 hours.

‘This is markedly higher than the rate of PET biodegradation by a microbial consortium recently reported,’ the researchers note. They add that the Galleria Mellonella usually feed on beeswax.

Further investigation is required to determine if related species have the capacity for PE degradation, it is argued. ‘Nevertheless, given the fast rate of biodegradation reported, these findings have potential for significant biotechnological applications,’ the researchers assert.

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