Could worms help provide a solution to plastic pollution?
According to Canadian researchers waxworms can survive purely on a diet of polyethylene – commonly used in plastic shopping bags – meaning we could soon have far better plastic biodegradation systems.
Waxworms, the caterpillar larvae of the greater wax moth, normally live in beehives and, as their name suggests, feast on the wax inside. But Dr Christophe LeMoine and Dr Bryan Cassone – who led the research at Brandon University, in Manitoba – were able to isolate a species of intestinal bacteria in the worms that was able to survive on the plastic for more than a year as its only source of nutrients.
Both the intestinal bacteria and the waxworms themselves can degrade the plastic independently if isolated from each other but were found to be much more effective when working together. Feeding the waxworms a 100 per cent polyethylene diet was shown to actually increase the microbes in their guts, as opposed to feeding them a normal diet or starving them.
“It seems there is a synergy between the bacteria and their waxworm hosts that accelerates plastic degradation,” said Dr LeMoine.
In the study, 60 waxworms – dubbed “plastivores” by the researchers – ate more than 30cm2 of a plastic bag in a week, producing glycol, a type of alcohol, as a by-product.
And while it may not be practical to assume that worms can eat away the problem of plastic pollution, gaining a better understanding of the conditions that lead the bacteria to thrive, as well as its synergistic relationship with the invertebrates, could make a significant impact. Researchers hope that further study will yield valuable insights that can be used to develop better plastic biodegradation systems.
“The problem of plastic pollution is too large to simply throw worms at,” said Dr Cassone. “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.”