New Plastic-Eating Enzyme Could Help Save the World! (Maybe)

In 2016, scientists made a revolutionary discovery at a waste center in Japan: bacteria that had evolved by natural selection to eat and break down plastic! These bacteria possess a plastic-eating enzyme that may transform the fight against pollution. Perplexed by this potential environmental lifeline, international research teams at the University of Portsmouth resolved to investigate the capabilities and evolutionary history of the enzyme.

Plastic water bottles gathered at a waste plant

Scientist and X-ray crystallographer John McGeehan from the University of Portsmouth and Gregg Beckham from the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) study the crystal structure of the new enzyme and have determined that it is able to fully break down PET plastic (polyethylene terephthalate), a kind of plastic typically found in bottles, which litter oceans and other marine ecosystems.

Structure of the plastic-eating enzyme

While manipulating the enzyme, McGeehan and Beckham and their research teams accidentally altered it to become even more efficient at plastic degradation. With the alteration, the enzyme can degrade PET plastic within three days.

Plastic degrades in the environment extremely slowly, so when people dispose of plastic bottles, they end up in landfills, bodies of water, or homes to all kinds of organisms. Plastic incineration increases carbon emission, which is known to contribute to climate change. Millions of tons of plastic bottles are produced each year, meaning that the rate of disposal and breakdown of plastic in bottles cannot keep up with the rate of their industrial production. Billions of pounds of plastic currently lie in the world's oceans. Plastic debris is devastating for wildlife, and has resulted in the death of thousands of marine mammals, seabirds, sea turtles, and fish through plastic entanglement and ingestion. The drastic endangerment of many marine species has the potential to devastate the environment and their respective marine species. As we learned this year, a decrease in the population of one species can cause the near-extinction of or over-reproduction in other species. Plastic debris also absorbs harmful pollutants, which can make their way into humans via the food chain after debris is ingested by marine wildlife. These pollutants can severely debilitate the human body by inducing random cancer-causing mutations and limiting hormone regulation, production, and signaling.

Remember to keep in mind that the engineering of the more efficient enzyme occurred coincidentally! Random mutations and alterations can determine the course of humans' lives—often for the worse. However, the serendipitous refinement of this beneficial plastic-eating enzyme reflects the fact that randomness can also positively contribute to environmental protection. Right now, the teams at the University of Portsmouth and NREL are working to further improve the efficiency of the enzyme, so that one day it can exponentially reduce the content of plastic in the world's oceans and marine habitats, thereby saving numerous species of organisms around the world.

For more information on plastic pollution, read:
Garbage in the Oceans: The Plastic Bag on the Side of the Highway