These Very Hungry Caterpillars May Help With Plastic After All!
Caterpillars are cute, they star in some of the world’s most popular children’s books, and turn into pretty butterflies and moths. And it turns out that they may offer the solution to our planet’s plastic challenge!
In 2017, a Spanish scientist and amateur beekeeper, Federica Bertocchini, accidently made an amazing discovery: the tiny, half-inch-long wax worms that she had gathered in a plastic bag because they were dining on the honeycomb in one of her beehives, had eaten their way out of it! Could this tiny caterpillar help solve one of the world’s most pressing environmental problems, that of plastic waste? Together with colleagues at the Institute of Biomedicine and Biotechnology of Cantabria, she was able to replicate this event in a lab, finding that wax worms broke down commonly used polyethylene plastic bags faster than other methods.
Now scientists from Brandon University in Canada, have just released research on how these caterpillars are able to do this, and it’s all down to their gut bacteria or microbiome. These findings may now guide efforts to find an effective biodegradation system to tackle plastic waste.
How to deal with the excess of plastic pollution in the world, particularly as it is famously slow in disintegrating on its own, remains a hot topic. In the half-century since plastic exploded into our lives, tiny bits of it have spread through our oceans, ecosystems and even our bodies. To date, humanity has struggled to get rid of it. It is estimated that eight million tons of plastic ends up in Earth’s oceans every year. According to the United Nations, over 8.3 billion tons of plastic has been produced since the early 1950s, with about 60 percent ending up in landfills or the natural environment reports Newsweek.
This is why these new findings are so exciting. “We found that waxworm caterpillars are endowed with gut microbes that are essential in the plastic biodegradation process, ” said Christophe LeMoine, an associate professor and chair of biology at Brandon University in Canada, to CNN.
Significantly, these researchers found that certain gut bacteria found in these tiny caterpillars could survive on plastic for over a year outside these tiny creatures, but that it took longer for it to be broken down this way than when the larvae ate it. This suggests that the caterpillar is instrumental to the process. LeMoine puts it like this: “This process seems reliant on a synergy between the caterpillars and their gut bacteria to accelerate polyethylene degradation.”
These Canadian researchers are the first to admit that their findings aren’t a quick fix, however, and emphasize that everyone still needs to continue working on reducing plastic waste. Team leader, Bryan Cassone, shares that “The problem of plastic pollution is too large to simply throw worms [at it], and there is still a lot to do before we can parlay this work into making a meaningful contribution.” He also admits that the larvae tend to eat less plastic with longer times on that type of diet. But “By understanding the process – why the breakdown of plastic occurs so rapidly in the waxworm—we can then begin to develop ways to really make a meaningful impact to plastic pollution.”
In the discussion that concludes their research findings, the Brandon University team are also careful to clarify the need to further test this plastic-degrading ability across different insect populations, and using other polymer formulations. They also emphasize the need for more research to explore the plastic breakdown process in vivo, “specifically how the caterpillar’s physiology, fitness and genetic underpinnings are directly affected by polyethylene breakdown.”
