Less than 10 percent of the 33 million tons of plastic Americans throw away every year gets recycled, but new research suggests plastic-munching worms could help get rid of the waste.
Scientists determined the mealworm, which is the larvae form of the darkling beetle, can live off a diet of Styrofoam and other forms of polystyrene, Stanford University reported.
"Our findings have opened a new door to solve the global plastic pollution problem," said Wei-Min Wu, a senior research engineer in the Department of Civil and Environmental Engineering at Stanford and one of the authors of the paper published in the journal Environmental Science and Technology.
The researchers observed 100 mealworms ate between 34 and 39 milligrams of Styrofoam (about the weight of a pill) within one day in a lab setting. Within a period of 24 hours, the worms converted about half the Styrofoam into carbon dioxide, and excreted the bulk of the remaining plastic as biodegraded fragment. The findings showed the mealworms that were fed a diet of Styrofoam were as healthy as those eating a normal diet, and their waste is believed to be safe to use as soil for crops. In the past researchers have shown waxworms possess gut microorganisms that allow them to biodegrade polyethylene, but it was widely believed that Styrofoam was non-biodegradable.
In the future, the researchers plan to study whether microorganisms within mealworms and other insects have the ability to biodegrade polypropylene, bioplastics, and microbeads. The discovery that insects could help biodegrade these materials would be extremely significant, especially because a recent study found a staggering eight tillion microbeads enter waterways in the United States on a daily basis.
"Microbeads are just one of many types of microplastic found in aquatic habitats and in the gut content of wildlife," said Chelsea Rochman, the David H. Smith Conservation Research Postdoctoral Fellow at the University of California/Davis, and lead author on the Oregon State University study.
