How wax worms could help reduce plastic pollution

The moth larvae could one day help clean the planet.

by Joseph Guzman | Oct. 05, 2022

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Two enzymes found in wax worm saliva are capable of degrading the durable material polyethylene.

Polyethylene is used in a range of diverse products worldwide.

Researchers said the two enzymes are the first and only known enzymes that can degrade polyethylene plastic rapidly without it first being treated.

The saliva of wax worms, which are moth larvae that infest beehives, may be a key to breaking down one of the most commonly produced plastics and could ultimately aid in the fight to reduce plastic pollution.

A new study published by Spanish researchers in Nature Communications demonstrates that two enzymes found in wax worm saliva are capable of degrading the durable material polyethylene. Polyethylene is used in a range of diverse products worldwide, including clear food wrap and shopping bags, as well as detergent bottles and vehicle fuel tanks, and total production volume of polyethylene in the U.S. surpassed 22 million metric tons in 2019.

Researchers from the Spanish National Research Council identified two enzymes, Demetra and Ceres, that can break down polyethylene into smaller molecules in just a few hours at room temperature. Previously, only a handful of microorganisms were known to break down the plastic polymers making up polyethylene, and those processes required pretreatments such as using heat or radiation.

Researchers said the two enzymes are the first and only known enzymes that can degrade polyethylene plastic rapidly without it first being treated.

“For plastic to degrade, oxygen must penetrate the polymer (the plastic molecule). This is the first step in oxidation, which is usually a result of exposure to sunlight or high temperatures, and represents a bottleneck that slows down the degradation of plastics like polyethylene, one of the most resistant polymers,” Federica Bertocchini, a lead author of the study, said in a statement.

“That’s why, under normal environmental conditions, plastic takes months or even years to degrade.”

The research team first discovered that wax worms could eat through common types of plastic in 2017 but were unsure just how that process took place.

Researchers note the mechanisms by which these enzymes are able to degrade plastic are still unknown, but they say the findings could open the door to new solutions to deal with the problem of plastic waste.

The amount of plastic pollution has proliferated over the last several decades, with an estimated 10 million tons of plastic making its way into the oceans each year. Polyethylene makes up about 30 percent of synthetic plastic production worldwide.