It has been discovered that enzymes in the wax worm’s saliva accelerate the degradation of polyethylene from decades to mere hours.
A worm may be the solution to the dilemma of what to do about one of the most prevalent forms of plastic pollution.
Spanish researchers have discovered that compounds in the wax worm’s saliva can degrade polyethylene, a particularly durable material.
Their investigation revealed that one hour of exposure to the creature’s saliva caused the plastic to degrade as much as several years of regular exposure to the outdoors.
Wax worms, the larvae of the wax moth, feed on the thick wax used by bees to construct honeycombs and are seen as a problem by beekeepers.
The study, which was published in the journal Nature Communications, found that two enzymes in the worm’s saliva that it employs to degrade wax also degrade plastic.
For plastic to decompose, oxygen must permeate its molecules, known as polymers, in a process known as oxidation.
The enzymes in the saliva caused this process to proceed in a couple of hours, without the need to expose the plastic to heat or radiation beforehand.
Polyethylene is the most frequently used plastic in the world and a major contributor to environmental degradation.
It was invented in 1933 and is affordable, durable, and nonreactive to food, resulting in its widespread use.
It is specifically engineered to be difficult to degrade and can remain intact for decades.
Synthetic enzymes have been developed.
Molecular biologist Federica Bertocchini of the Spanish National Research Council (CSIC), who conducted the study, remarked that this discovery “changes the paradigm of plastic biodegradation.”
She went on to explain that not only had they discovered which enzymes break down the plastic, but they had also managed to synthesize them, eliminating the need for billions of wax worms.
As the worms metabolize the polyethylene, a substantial amount of carbon dioxide would be produced. There would also be several practical disadvantages.
In the previous three decades, plastic consumption has surged, with hundreds of millions of tonnes ending up as waste annually and less than ten percent being recycled.
In March of this year, the United Nations passed a historic agreement to develop the world’s first global plastic pollution convention, with a legally binding accord expected to be finalized by 2024.
