Over a trillion plastic bags are used every year, most of them eventually ending up in landfills and polluting the environment. Since the synthetic polymers that make up the plastic bags are mostly resistant to biodegradation, it has become necessary to look for efficient ways to get rid of this environmental hazard. Research published in an international journal, Current Biology, may just have found a solution to this problem.
The paper reports the fast biodegradation of polyethylene (PE) by larvae of the wax moth Galleria mellonella, producing ethylene glycol. According to The Economist, Federica Bertocchini, a biologist at Cantabria University in Spain, made this discovery by accident. She was tending to her beehives when she found caterpillars chewing through the wax in order to get to the honey. Bertocchini decided to collect a few specimen of worms in a plastic bag so she could identify the honey thieves later. However, she later found that the worms had made an escape by eating through the bag. Bertocchini and her team have identified the worms as Galleria mellonella, commonly known as wax worms that can digest plastic.
The researchers have found that when a PE film is left in direct contact with the worms, holes start appearing in it after just 40 minutes, with each worm making an average of 2.2 holes. They have determined that it will take about 100 caterpillars roughly 12 hours to eat a small portion of an ordinary plastic shopping bag.
Bertocchini and her colleagues have found that the worm not only ingests the PE but also chemically transforms the plastic into ethylene glycol.
Plastic is not normally a part of these worms’ diet but the researchers speculate that they are able to eat it because the chemical structure of polyethylene is somewhat similar to wax. These worms lay their eggs inside beehives and the hatched worms grow on the beeswax. It is likely that digesting beeswax and PE involves breaking down similar types of chemical bonds.
“We 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,” says Bertocchini in a statement.
“However, we should not feel justified to dump polyethylene deliberately in our environment just because we now know how to biodegrade it,” she adds.
Several questions still remain unaddressed about the effectiveness of using these worms in dealing with garbage disposal. It remains to be seen whether the byproduct formed by the worms eating the plastic is toxic or not. Is this the answer to the large-scale problem of plastic waste disposal? It might be too soon to say.
Recently, researchers in Pakistan and China had discovered a fungus capable of biodegrading plastic. The fungus was discovered in a garbage heap in the city of Islamabad in Pakistan.