A common insect larva that eats beeswax has been found to break down chemical bonds in the plastic used for packaging and shopping bags at uniquely high speeds. Scientists say the discovery could lead to a biotechnological approach to the polyethylene waste that chokes ocean ecosystems听and landfill sites.
A common insect larva that eats beeswax has been found to break down chemical bonds in the plastic used for packaging and shopping bags at uniquely high speeds. Scientists say the discovery could lead to a biotechnological approach to the polyethylene waste that chokes ocean ecosystems听and landfill sites.
探花直播caterpillar produces something that breaks the chemical bond, perhaps in its salivary glands or a symbiotic bacteria in its gut
Paolo Bombelli
Scientists have found that a caterpillar commercially bred for fishing bait has the ability to biodegrade polyethylene: one of the toughest and most used plastics, frequently found clogging up landfill sites in the form of plastic shopping bags.
探花直播wax worm, the larvae of the common insect Galleria mellonella, or greater wax moth, is a scourge of beehives across Europe. In the wild, the worms live as parasites in bee colonies. Wax moths lay their eggs inside hives where the worms hatch and grow on beeswax 鈥 hence the name.
A chance discovery occurred when one of the scientific team, Federica Bertocchini, an amateur beekeeper, was removing the parasitic pests from the honeycombs in her hives. 探花直播worms were temporarily kept in a typical plastic shopping bag that became riddled with holes.
Bertocchini, from the Spanish National Research Council (CSIC), collaborated with colleagues Paolo Bombelli and Christopher Howe at the 探花直播 of Cambridge鈥檚 Department of Biochemistry to conduct a timed experiment.
Around a hundred wax worms were exposed to a plastic bag from a UK supermarket. Holes started to appear after just 40 minutes, and after 12 hours there was a reduction in plastic mass of 92mg from the bag.
Scientists say that the degradation rate is extremely fast compared to other recent discoveries, such as bacteria reported last year to biodegrade some plastics at a rate of just 0.13mg a day. Polyethylene takes between 100 and 400 years to degrade in landfill sites.听
"If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable," said Cambridge's Paolo Bombelli, first author of the study published today in the journal .
"This discovery could be an important tool for helping to get rid of the polyethylene plastic waste accumulated in landfill sites and oceans."
Polyethylene is largely used in packaging, and accounts for 40% of total demand for plastic products across Europe 鈥 where up to 38% of plastic is discarded in landfills. People around the world use around a trillion plastic bags every single year.
Generally speaking, plastic is highly resistant to breaking down, and even when it does the smaller pieces choke up ecosystems without degrading. 探花直播environmental toll is a heavy one.
Yet nature may provide an answer. 探花直播beeswax on which wax worms grow is composed of a highly diverse mixture of lipid compounds: building block molecules of living cells, including fats, oils and some hormones.
探花直播researchers say it is likely that digesting beeswax and polyethylene involves breaking similar types of chemical bonds, although they add that the molecular detail of wax biodegradation requires further investigation.
鈥淲ax is a polymer, a sort of 鈥榥atural plastic,鈥 and has a chemical structure not dissimilar to polyethylene,鈥 said CSIC鈥檚 Bertocchini, the study鈥檚 lead author.
探花直播researchers conducted spectroscopic analysis to show the chemical bonds in the plastic were breaking. 探花直播analysis showed the worms transformed the polyethylene into ethylene glycol, representing un-bonded 鈥榤onomer鈥 molecules.听
To confirm it wasn鈥檛 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.
鈥 探花直播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,鈥 said Bombelli.
鈥 探花直播caterpillar produces something that breaks the chemical bond, perhaps in its salivary glands or a symbiotic bacteria in its gut. 探花直播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.鈥
As the molecular details of the process become known, the researchers say it could be used to devise a biotechnological solution on an industrial scale for managing polyethylene waste.听
Added Bertocchini: 鈥淲e are planning to implement this finding into a viable way to get rid of plastic waste, working towards a solution to save our oceans, rivers, and all the environment from the unavoidable consequences of plastic accumulation.鈥
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