17. Mar 2020
Dr. Christophe LeMoine and Dr. Bryan Cassone of BU’s Department of Biology have found that waxworms, the caterpillar larvae of the greater wax moth, can survive on a diet of polyethylene, a type of plastic used in shopping bags and many other applications.
Working with BU students Sachi Villanueva, Harald Grove and Oluwadara Elebute, the researchers isolated a species of intestinal bacteria in the worms that was able to survive on plastic for more than a year as its only source of nutrients.
“Plastic-eating bacteria are known, but in isolation they degrade plastics at a very slow rate,” Dr. LeMoine said. “Likewise, when we treated the caterpillars with antibiotics to reduce their gut bacteria, they were not able to degrade the plastic as easily. So, it seems that there is a synergy between the bacteria and their waxworm hosts that accelerates plastic degradation.”
In fact, the study showed that feeding the waxworms a 100 percent polyethylene diet increased the microbes in their guts when compared to worms that were fed their normal diet or were starved, suggesting the bacteria thrive on plastics. The researchers have dubbed these worms “plastivores.”
Glycol, a form of alcohol, was created as a byproduct of the plastic degradation. The researchers are still working to identify the exact nature of the end products.
“Worms that eat our plastic waste and turn it into alcohol sounds too good to be true. And in a way it is,” said Dr. Cassone. “The problem of plastic pollution is too large to simply throw worms at. But if we can better understand how the bacteria works together with the worm and what kind of conditions cause it to flourish, perhaps this information can be used to design better tools to eliminate plastics and microplastics from our environment.”
LeMoine and Cassone are continuing to study the waxworms as well as the bacteria to learn more about the characteristics that allow them to work so well together.
“This is intriguing research that is showing promising results as we tackle a worldwide problem,” said Dr. Bernadette Ardelli, Dean of Science at BU. “It’s rewarding to see our faculty taking on important issues like this as well as to see our students gaining valuable experience, while also making their own contributions to an exciting discovery.”
Image: Bryan Cassone (from left to right), Harald Grove, Christophe LeMoine and Sachi Villanueva have been studying the ability of waxworms to eat and biodegrade plastic. Missing from the picture is Oluwadara Elebute.