Plastic-eating worms to ease pollution problems

PALO ALTO, Calif., Sept. 30 (UPI) -- Can worms eat a way out of our plastic pollution problems? Probably not all on their own, but new research suggests they can help.

A new study out of Stanford University proves mealworms can subsist entirely on a diet of Styrofoam and other types of polystyrene, the most common form of plastic.

In lab experiments, 100 mealworms were able to put away 34 to 39 milligrams of Styrofoam per day. Half the plastic was converted to CO2, while the other half was excreted as a biodegraded pellets resembling rabbit droppings.

"Our findings have opened a new door to solve the global plastic pollution problem," Wei-Min Wu, co-author of the new study and senior research engineer at Stanford, said in a press release.

Mealworms -- the larvae form of the darkling beetle -- are the second type of worm Wu and his colleagues have found to possess intestinal microorganisms capable of breaking down polystyrene. Waxworms, the larvae of Indian mealmoths, can also digest the foamed plastic.

Testing shows the plastic-eating worms are just as healthy as worms eating a more traditional diet of grains.

The latest findings by Wu and co-author Craig Criddler were detailed this week in the journal Environmental Science and Technology.

"There's a possibility of really important research coming out of bizarre places," said Criddle, a senior fellow at the Stanford Woods Institute for the Environment. "Sometimes, science surprises us. This is a shock."

Wu and Criddler are currently 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. A marine equivalent of the mealworm could help rid ocean waters of mounting plastic pollution.

More work is needed, researchers say, to identify the microbes essential to the digestion of plastics. Scientists also want to test what happens when plastic-eating worms are then eaten by other animals.