For centuries, we have been trying to find a solution to the ever growing problem of plastic pollution. It is estimated that more than 100 billion plastic bags are used in the U.S. every year. And in order to create such large quantities of plastic, more than 12 million barrels of oil is required. Scientists estimate that more than 300 million tons of plastic are produced worldwide every year. So, how are we going to get rid of all these plastic materials that take centuries to decompose? European scientists may have found a unique solution to this problem. The discovery that tiny worms can eat away plastic was made in 2017 and since then, scientists have been working to create enzymes that can digest plastic.
In 2017, they discovered that a common insect was capable of chewing sizable holes in a plastic shopping bag within 40 minutes.
The discovery was led by Federica Bertocchini, a developmental biologist at the University of Cantabria in Spain. Federica Bertocchini discovered the unusual characterists by accident. The biologist was cleaning out her backyard beehives one day, when she removed some wax worms (Galleria mellonella) living in the hive and placed them in a plastic bag. After cleaning the hive, Bertocchini went to get the worms and discovered that the plastic bag containing the worms were riddled with tiny holes.
Bertocchini immediately understood what was going on. The little creatures are called wax worms because they live on the wax in bee hives.
While there are organisms capable of eating plastic materials, they do take a considerable amount of time to break them down. However, the waxworms can eat their way through the plastic bags in a far shorter period of time. The worms occupy bee colonies and eat wax, which is also a polymer like plastic; consisting of a long string of carbon atoms held together. Bertocchini discovered that both the plastic bag and wax had a similar carbon backbone.
In order to put her finding to the test, Bertocchini teamed up with fellow scientists Paolo Bombelli and Christopher to determine if they are really capable of eating plastic.
Bertocchini and her team placed 1oo waxworms inside a polyethylene plastic bag and recorded the activity. The study found that each of them worms were capable of creating an average of 2.2 holes per hour. However, overnight, the worms managed to degrade 92 milligrams of the plastic bag. After calculating their breakdown rate, the team discovered that the same 100 worms would take nearly a month to completely break down an average, 5.5 gram plastic bag.
The team also discovered that an enzyme within the worms or the bacteria living in and on their bodies was also capable of dissolving plastic.
After discovering that their bodies also contained enzymes that can break down plastic, scientists tested their theory. Bertocchini’s team spread some wax worm guts on a piece of plastic and discovered that they too were capable of eating through plastic. These worms were breaking down plastic into ethylene glycol, which can be used to make polyester or antifreeze. This is a crucial scientific discovery and the next step to progress is to isolate that chemical.
Although the waxworms themselves cannot make much of a difference in reducing plastic pollution in our planet, the enzymes produced can surely help scientists discover new methods to breakdown plastic.
Munching on plastic isn’t that big of a change in diet for wax worms. However, the rate of which they breakdown plastic isn’t sufficient enough to reduce the plastic that our planet is filled with. Bertocchini said in a press release that “hopefully the wax worm’s special skills can help us do something about the billions of plastic bags thrown away every year”.
A 2016 study identified the enzymes in a species of bacteria that was also capable of breaking down a type of plastic called poly(ethylene terephthalate). Scientists believe that there are probably lots of other worm species and bacteria out there that are capable of doing the same thing. At the same time, scientists explain that the solution to reducing plastic is to focus on producing less and recycling more. The worms and their enzymes should be used to discover methods to reduce the already present plastic.
“What we are hoping to do is use this enzyme to turn this plastic back into its original components, so we can literally recycle it back to plastic. It means we won’t need to dig up any more oil and, fundamentally, it should reduce the amount of plastic in the environment.”