Researchers find caterpillars that can chew and break down plastic
Tiny insects may someday be enlisted to break down plastic in landfills.
— -- Since plastic was invented, figuring out how to get rid of the stuff quickly without harming the environment has been a puzzle. This week researchers found one unlikely but possible solution: caterpillars.
Specifically a type of caterpillar called a Galleria mellonella or "wax worm" which has been found to be able to break down common plastic material, according to a study published yesterday in the Current Biology journal. The "wax worms" turn into greater wax moth or honeycomb moth, which often eat honeycombs by breaking down the wax structure.
"We have found that the larva of a common insect, Galleria mellonella, is able to biodegrade one of the toughest, most resilient, and most used plastics: polyethylene," co-author Federica Bertocchini of the Institute of Biomedicine and Biotechnology of Cantabria in Spain, said in a statement Monday.
Plastics, created from fossil fuel oils, remain a staple of modern life. While some recycling initiatives have helped keep the material from ending up in nature, every year an estimated 8 million tons of plastic end up in our oceans alone, according to the United Nations Regional Information Center of Western Europe.
The researchers used a plastic bags made from polyethylene (PE) a common plastic substance, according to the study. They found that with a common shopping bag made of polyethylene, the insects were able to eat their way through after approximately 40 minutes. It took about 14 hours for 100 caterpillars to break down about 13 percent of the bag, according to the study. The insects were able to break the PE down to an organic compound called ethylene glycol.
Prior attempts at biodegrading PE with bacteria, fungus and nitric acid led the plastic to slowly disintegrate over weeks to months but not hours, according to the study authors.
While the researchers are still trying to understand the chemical reaction that allows the worm to break down the plastic, they say these insects are likely primed to break down the plastic because of their normal diet of wax honeycombs, which contains similar chemical bonds to the ones found in PE.
"Wax is a polymer, a sort of natural plastic, and has a chemical structure not dissimilar to polyethylene," Bertocchini said in the statement.
