Dive Brief:
- Wei-Min Wu, a senior research engineer in the Department of Civil and Environmental Engineering at Stanford, has co-authored two companion studies that suggest mealworms can subsist on a diet of Styrofoam and other types of polystyrene.
- Researchers found that in the lab, 100 mealworms — the larvae form of the darkling beetle — ate between 34 and 39 milligrams of Styrofoam each day. The worms converted half of the Styrofoam into carbon dioxide, and the excreted, biodegraded waste from the worms appeared safe to use as crop soil. Mealworms that were fed a plastic diet were as healthy as those eating a regular diet, according to Wu.
- The development is significant due to the belief that Styrofoam is non-biodegradable. Researchers will continue to study mealworms and other insects to see if they can biodegrade other materials such as polypropylene, microbeads, and bioplastics.
Dive Insight:
This research development comes at a crucial time, as waste industry professionals have had increasingly heated debates regarding the recyclability of Styrofoam. The decision to ban or recycle Styrofoam has been left up to the discretion of individual municipalities, and each side of the argument has shown strong support. Recently in New York City, a judge overturned the city's ban on polystyrene packaging calling it "arbitrary and capricious," however many opponents have argued that the products "cause real environmental harm" and are not recyclable.
Plastic-eating mealworms may open a new door to solve the rapidly growing problem of plastic waste, while maintaining an eco-friendly practice. The Stanford studies, published in Environmental Science and Technology, "are the first to provide in-depth evidence of bacterial degradation of plastic in an animal's gut," according to Stanford News Service.
"There's a possibility of really important research coming out of bizarre places," Craig Criddle, a professor of civil and environmental engineering who supervises plastics research by Wu and others at Stanford, said in the report. "Sometimes, science surprises us. This is a shock."
The scientists also note that continued research will involve searching for the "marine equivalent" of the mealworm to digest marine debris. The research will require scientists to look into the enzymes that break down polymers, in order to determine how to best degrade the plastics — and maybe guide manufacturers in designing polymers that break down more easily.