Plastic is choking our environment. About 400 million tons of plastic waste is thrown out every year with between 75 to 199 million tons floating in oceans and endangering aquatic ecosystems, according to the UN. The problem is so dire that there are five literal garbage patches strewn across the world’s oceans. The largest, in the Pacific Ocean, is twice the size of Texas and affects the health of millions of birds and marine animals every year.
Cleaning up plastic waste is a doable but extremely difficult task. The fundamental issue is that plastic isn’t biodegradable. It takes an ungodly amount of time to break down—and when it does, it releases microplastics that can find its way into our bodies through drinking water and food.
However, in recent years, worms and other insects have emerged as unlikely heroes in our fight against plastic waste. Scientists have discovered that these little creepy crawlers contain microbes in their gut that can digest polyethylene—the kind of plastic used in shopping bags, shampoo bottles, and containers. And now, in a study published Thursday in the journal Microbial Genomics, researchers at the University of Queensland in Australia have discovered that larva of the darkling beetle—commonly called superworms—have the ability to dine on polystyrene, a plastic used in styrofoam, plastic plates, cups, and elsewhere.
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“There are few reports out there that insect larvae are actually pretty good at damaging plastic and eating it,” Chris Rinke, a microbiologist at the University of Queensland and co-author of the study, told The Daily Beast. “That’s why we started with superworms because they are quite larger than other insect larvae and we thought they would be more efficient in breaking down plastics.”
To test this idea out, Rinke and his team fed three groups of superworms either polystyrene, bran, or nothing over a three-week period. Within 24 hours, the polystyrene-fed superworms were going to town on the plastic; by the end of the experiment, much to the researchers' surprise, these nearly two-inch long larvae were positively thriving and even gained some weight.
Superworms eating on plastic.
Hung VuMuch like a human gut, insects have their own unique microbiome that plays a critical role in nutrition, physiology, and even behavior. When the superworms break down the polystyrene, bacteria in their gut digest the small chunks even further with specialized plastic-degrading enzymes, Rinke explained.
The team is still in the process of trying to figure out exactly which enzymes are facilitating the plastic lunch session. That information, Rinke said, could revolutionize the way we dispose of certain types of plastics, incentivizing recycling efforts, and reducing the presence of plastics in landfills.
“You could have a big bioreactor, have the enzymes in there,” said Rinke. “So you would first shred the polystyrene and the enzymes could chemically break [it] down. That scale is way better than having large batches of superworms.”
