Americans throw out about 2.5 billion styrofoam cups per year which we had no way to degrade so, yeah, yeah, kind of a big deal, guys. The remainder ends up in landfills or the environment, presenting challenges ranging from water contamination to toxicity in wildlife.
In a lab setting, the mealworms ate between 34 and 39 milligrams of Styrofoam per day, about the weight of a small pill.
Into this disaster ride Wu, of Stanford’s Department of Civil and Environmental Engineering, and his team, beared hundreds of common mealworms that were raised from birth on a diet of nothing but styrofoam.
The development is significant due to the belief that Styrofoam is non-biodegradable. In addition, they want to find out how the mealworms’ Styrofoam-based diet affects animals further up the food chain.
Wu and Criddler are now collaborating with scientists at Beihang University in China to identify other types of insects capable of biodegrading plastic waste, and to see if mealworms can digest other types of plastics besides polystyrene.
Researchers show that the mealworm can live on a plastic diet. Not only do the worms happily feed on the non-biodegradable plastic, but they also convert it into carbon dioxide and nutrient-rich waste for plants to use.
“Our findings have opened a new door to solve the global plastic pollution problem”, said Wu.
Within 24 hours, they excreted the bulk of the remaining plastic as biodegraded fragments that look similar to tiny rabbit droppings.
But even if mealworms can help with plastic waste management, Wu said it’s not a substitution for recycling.
In fact, worms that dined regularly on plastic appeared to be as healthy as their non-plastic-eating companions, and researchers think that the waste they produce could be safely repurposed in agriculture. Plastic waste is a particular concern in the ocean, where it fouls habitat and kills countless seabirds, fish, turtles and other marine life.
More work is needed, researchers say, to identify the microbes essential to the digestion of plastics. Learning more about the enzymes responsible for plastic degradation may lead to scientists developing more powerful enzymes.
“There’s a possibility of really important research coming out of weird places”, said Criddle, a senior fellow at the Stanford Woods Institute for the Environment. Craig Criddle, of Stanford Univ. “Sometimes science surprises us. This is a shock”.