Scientists Accidentally Develop ‘Mutant’ Enzyme That Eats Plastic

Apr 17, 2018 by

Researchers in the UK and the U.S. have inadvertently engineered an enzyme that eats up plastic.

The enzyme is able to digest PET (polyethylene terephthalate)—the same material used in the ubiquitous plastic bottle that’s clogging up landfills, coastlines and oceans around the world.

Amazingly, this discovery only happened by chance. Scientists from the University of Portsmouth in the UK and the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) were examining the structure of a natural enzyme, Ideonella sakaiensis, found in 2016 at a Japanese waste recycling center. This enzyme could already break down PET plastic—it just doesn’t do it very quickly.

To understand how Ideonella sakaiensis evolved, the research team “tweaked” the structure of the enzyme by adding some amino acids, according to John McGeehan, a Portsmouth professor who co-led the work. They ended up creating an enzyme that worked even faster than the natural one.

“Surprisingly, we found that the PETase mutant outperforms the wild-type PETase in degrading PET,” said NREL materials scientist Nic Rorrer.

McGeehan added, “Serendipity often plays a significant role in fundamental scientific research and our discovery here is no exception.”

The modified enzyme, called PETase, can break down PET in just a few days—a stunning discovery that could help fight the world’s escalating plastic crisis.

Electron microscope image of enzyme degrading PET plastic Dennis Schroeder / NREL“After just 96 hours you can see clearly via electron microscopy that the PETase is degrading PET,” said NREL structural biologist Bryon Donohoe.

“And this test is using real examples of what is found in the oceans and landfills.”

As BBC News explained, PETase works by reversing the manufacturing process by reducing polyesters back to their building blocks so it can be used again.

When you drink soda, water or juice from a plastic bottle, those bottles are almost never made from recycled plastic. Additionally, as the Guardian noted, the plastic bottles that do get recycled can only be turned into polyester fibers for carpet or fabric.

But this new finding suggests a way to turn plastic bottles back into plastic bottles.

“They could be used to make more plastic and that would avoid using any more oil … Then basically we’d close the loop. We’d actually have proper recycling,” McGeehan told BBC News.

The team’s finding was published Monday in the journal Proceedings of the National Academy of Sciences.

The researchers are now working to improve PETase to see if it can work on an industrial scale. About one million plastic bottles are purchased around the world every minute, with that number predicted to increase another 20 percent by 2021.

“This unanticipated discovery suggests that there is room to further improve these enzymes, moving us closer to a recycling solution for the ever-growing mountain of discarded plastics,” McGeehan said.

Show Comments (2)

5 Ways to Make This Earth Day Really Count

By Courtney Lindwall

Earth Day 2018 is here—and the Earth needs us more than ever. The Trump administration is waging a no-holds-barred assault on our clean energy future, the air we breathe and water we drink, our public lands, and our endangered species. But the grassroots environmental movement is energized, and every action each of us takes to honor the planet matters. Here are a few effective—and fun—ways to make a difference this year.

Keep reading…

Greenpeace Finds Amazon Reef Formation Where Total Plans to Drill for Oil

A team of scientists on board the Greenpeace Esperanza ship have documented the existence of a rhodolith field where French company Total intends to drill for oil, 120km off the northern coast of Brazil.

The finding proves the existence of a reef formation in the area and invalidates Total’s Environmental Impact Assessment (EIA), which states the closest reef formation is 8 kilometers (approximately 5 miles) away from one of the oil blocks.

Keep reading…

All wool that goes into the making of products retailed at REI must be sourced from humanely treated sheep. It’s one of several new standards for the co-op’s suppliers. Tutye / iStock

REI Rolls Out Tough Sustainability Standards for All Its Brands

By Katie O’Reilly

Those who love to recreate outdoors make for staunch environmental advocates. Last week, consumer co-op REI announced plans that should make it easier for its adventurer members to find products that support their values. By the fall of 2020, REI will sever its business relationships with any of its 1,000-plus suppliers that don’t meet stringent new requirements in areas including environmental impact, chemical usage, animal welfare, and labor safety and fairness.

Keep reading…

Animal Rights Groups Slam ‘Inhumane’ Bear Stunt at Russian Soccer Match

Animal rights organizations expressed outrage after footage emerged of a trained bear named Tima performing ahead of a soccer match on Saturday between third-tier Russian teams Mashuk-KMV and Angusht.

The clip shows a muzzled bear led to the stadium by a handler. It lifts its arms up and down, gets on its hind legs and hands a soccer ball to the referee. It then makes clapping motions in front of the cheering crowd.

Keep reading…
The Miami coast is especially vulnerable to sea level rise. NOAA’s National Ocean Service / Flickr

Florida Youth Sue Governor for Climate Action

Climate change poses a key risk to low-lying Florida. When Climate Central ranked the 25 U.S. coastal cities that would be most vulnerable to coastal flooding in 2050 due to sea level rise projections, 20 of them were in the Sunshine State.

But Florida Governor Rick Scott has a history of sticking his head in the disappearing sand. In 2015, reports surfaced that his government had banned the Florida Department of Environmental Protection from even using the words “climate change” in reports. Though he denies those charges, he also denies climate change. When asked to comment on it, he famously replied, “I’m not a scientist.”

Keep reading…
Popular

Which Coffee Is Better for Biodiversity?

By Jason Daley

When coffee consumers think about the most sustainable way to manage their caffeine habit, they normally think about the cup it’s in: Is it recyclable? But what about the coffee itself? Some coffee plantations require clear-cutting; will drinking one type of coffee have a bigger impact on the environment than another?

Keep reading…
Andrew Wheeler during his confirmation hearing to be deputy administrator of the U.S. Environmental Protection Agency. Media Punch Inc / Alamy

Who Is Andrew Wheeler? (And Why You Should Be Afraid of Him)

By Jeff Turrentine

Scott Pruitt’s long record of misdeeds and malfeasance finally seems to have caught up with him. Whether his numerous scandals, recently making headlines, will cost him his job as head of the U.S. Environmental Protection Agency (EPA) is still an open question.

Keep reading…
Daily Brian / Flickr

Environment Committee Chair Seeks Answers From Pruitt Over Multiple Email Addresses

The chair of the Senate Environment and Public Works Committee is seeking details about U.S. Environmental Protection Agency (EPA) chief Scott Pruitt‘s use of four different agency email addresses.

The Hill reported that Sen. John Barrasso, R-Wyo., sent a letter Friday to Pruitt asking him to “confirm that the EPA does in fact search all your official email accounts when responding to [Freedom of Information Act] requests?” The multiple email addresses were first reported last week by the Washington Post.

Keep reading…
Protest in Burnaby Mountain in BC on April 7. Protect the Inlet / Flickr

Trudeau Pledges Taxpayer Money, New Laws to Salvage Controversial Pipeline

Canadian Prime Minister Justin Trudeau said Sunday he is ready to offer financial aid and new legislation to push forward the contentious Trans Mountain Pipeline expansion that will triple production of tar sands going from Alberta to British Columbia.

Houston-based developer Kinder Morgan has threatened to scrap the $7.4 billion (USD $5.9 billion) project unless political and legal opposition is resolved by May 31. The energy giant’s move came after fierce opposition from environmental activists and Indigenous groups, as well as escalating tension between the Albertan and British Columbian governments.

Keep reading…
Energy

Cap Sante, Anacortes, WA. -jon / Flickr

Landmark Agreement: Shipping Industry to Cut Emissions

On Friday, the 170+ nations in the International Maritime Organization set the first-ever emissions target for the shipping industry and agreed to halve CO2 emissions by 2050, based on 2008 levels.

The unprecedented deal was welcomed by activists as a first step towards meeting the Paris agreement targets. The IMO nations also began a process to ban heavy fuel oil in Arctic waters.

Keep reading…
Climate

Earth Day Initiative

8 Events to Attend This Earth Day in NYC

Earth Day has a storied history. It was founded in 1970, as polluted rivers were catching fire, biodiversity was rapidly declining and smog was a fact of life in cities throughout the U.S. That year, an astounding twenty million people decided they had had enough. Together, they threw one of the largest protests in history in the form of activities and festivals where they protested environmental degradation and also celebrated Earth’s bounty.

Keep reading…

Leave a Reply

Your email address will not be published.