Newly discovered bacteria can eat plastic bottles

March 11, 2016 by Deborah Netburn, Los Angeles Times
Credit: Charles Rondeau/ public domain

A team of Japanese scientists has found a species of bacteria that eats the type of plastic found in most disposable water bottles.

The discovery, published Thursday in the journal Science, could lead to new methods to manage the more than 50 million tons of this particular type of plastic produced globally each year.

The plastic found in is known as polyethylene terephthalate, or PET. It is also found in polyester clothing, frozen-dinner trays and blister packaging.

"If you walk down the aisle in Wal-Mart you're seeing a lot of PET," said Tracy Mincer, who studies plastics in the ocean at the Woods Hole Oceanographic Institution in Massachusetts.

Part of the appeal of PET is that it is lightweight, colorless and strong. However, it has also been notoriously resistant to being broken down by -what experts call "biodegradation."

Previous studies had found a few species of fungi can grow on PET, but until now, no one had found any microbes that can eat it.

To find the plastic-eating bacterium described in the study, the Japanese research team from Kyoto Institute of Technology and Keio University collected 250 PET-contaminated samples including sediment, soil and wastewater from a plastic bottle recycling site.

Next they screened the microbes living on the samples to see whether any of them were eating the PET and using it to grow. They originally found a consortium of bugs that appeared to break down a PET film, but they eventually discovered that just one of was responsible for the PET degradation. They named it Ideonella sakainesis.

Further tests in the lab revealed that it used two enzymes to break down the PET. After adhering to the PET surface, the bacteria secretes one enzyme onto the PET to generate an intermediate chemical. That chemical is then taken up by the cell, where another enzyme breaks it down even further, providing the bacteria with carbon and energy to grow.

The researchers report that a community of Ideonella sakaiensis working this way could break down a thin film of PET over the course of six weeks if the temperature were held at a steady 86 degrees Fahrenheit.

Mincer said the study was impressive and did a good job showing that these organisms were eating the plastic pretty well. However, he said it was not immediately clear whether or not it would help keep plastics out of the ocean, for example.

"When I think it through, I don't really know where it gets us," he said. "I don't see how microbes degrading plastics is any better than putting bottles in a recycling bin so they can be melted down to make new ones."

He added that the research could make it easier to identify other microbes that might have similar PET-degrading capabilities.

"This process could be quite common," he said. "Now that we know what we are looking for, we may see these microbes in many areas around the world."

Explore further: Scientists make renewable plastic from carbon dioxide and plants

More information: U. T. Bornscheuer. Feeding on plastic, Science (2016). DOI: 10.1126/science.aaf2853

S. Yoshida et al. A bacterium that degrades and assimilates poly(ethylene terephthalate), Science (2016). DOI: 10.1126/science.aad6359

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21 comments

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rrrander
3.4 / 5 (7) Mar 11, 2016
Ever see the movie, (original one, not the travesty remake) "The Andromeda Strain?" Remember what happened when the bacteria that ate plastic got into the fighter plane?
betterexists
4.2 / 5 (5) Mar 11, 2016
So, Next step is to synthesize those 2 Enzymes in the Factories - Even making Better Enzymes!
LifeBasedLogic
Mar 11, 2016
This comment has been removed by a moderator.
stezlaf
4.2 / 5 (6) Mar 11, 2016
So, apparently the boy who first discovered this in 2009 doesn't deserve any credit?

http://www.mnn.co...-plastic
katesisco
2.3 / 5 (6) Mar 11, 2016
Exactly. And in the bigger picture I recall how the Etruscan's were certain their time was over. Nothing could dissuade them otherwise. In this ---buili-it-and-they-will-come-model -- lets look at what we have put on the table: radioactivity, plastic, pharma, genetically engineered fish, pigs, corn, sunflower, rape, soy, etc.
Will there be any space for us unengineered species in this faux world? I suspect those enjoying the feast of artificiality will have so strong a chenical attack set of molecules and enzymes that we would be dessert.
Phys1
4.5 / 5 (8) Mar 11, 2016
Ever see the movie, (original one, not the travesty remake) "The Andromeda Strain?" Remember what happened when the bacteria that ate plastic got into the fighter plane?


I hear you. Just another thing out of control because people refuse to make better choices.


It is an SF movie. It did not really happen.
Thirteenth Doctor
4.3 / 5 (6) Mar 11, 2016
It is an SF movie. It did not really happen.


I am sure that Sharknado happened though.
dschlink
5 / 5 (4) Mar 11, 2016
Note: the key word is 'discovered', not engineered.
dustywells
5 / 5 (1) Mar 11, 2016
"Will there be any space for us unengineered species in this faux world?"

You haven't heard about CRISPR?
Caliban
5 / 5 (3) Mar 12, 2016
I would say that a more-to-the-point question is: "Do these bacteria biodegrade the other harmful components of the plastic, as well?"

That would be a highly desirable co-process.
tkjtkj
3.7 / 5 (3) Mar 12, 2016
... -- lets look at what we have put on the table: radioactivity, plastic, pharma, genetically engineered fish, pigs, corn, sunflower, rape, soy, etc.
Will there be any space for us unengineered species in this faux world? ...


Do add 'people' to your long list of 'techie-modified' items: recent news reports show a community of people who are implanting chips under their skin, to "make a better, more capable human" .. I didn't just make this up!!!
KipHansen
2.8 / 5 (4) Mar 12, 2016
Bacteria and other microorganisms have been eating plastic for a very long time. Plastics in the ocean have been found to break down into smaller and smaller pieces until they are so small that microorganisms eat them -- and viola -- gone.

PET eating organisms may be new -- but when I researched plastics in the oceans, I found nothing particularly different about PET -- all floating plastics breakdown and eventually disappear.

Plastics that sink take longer to break down -- some may not break down at all -- in which case they become like rocks -- home for various plants and creatures.
Caliban
3.5 / 5 (4) Mar 12, 2016
Bacteria and other microorganisms have been eating plastic for a very long time. Plastics in the ocean have been found to break down into smaller and smaller pieces until they are so small that microorganisms eat them -- and viola -- gone.

PET eating organisms may be new -- but when I researched plastics in the oceans, I found nothing particularly different about PET -- all floating plastics breakdown and eventually disappear.

Plastics that sink take longer to break down -- some may not break down at all -- in which case they become like rocks -- home for various plants and creatures.


Well, gollygee, Mr. Kippers --everything's sunshine and moonbeams!
torbjorn_b_g_larsson
4 / 5 (4) Mar 13, 2016
"us unengineered species".

We are as much 'engineered' by evolution as any other species, moreover we are one of a few social species that have changed ourselves. (Smaller teeth and snouts due to 3 Myrs food technology; larger, more expressive faces; cryptic estrous; et cetera). And of course we have changed our companion species the last 10 kyrs, in the risky - as always - process of selection, where 10s of thousands of alleles inadvertently sweep with the traits that we want to change.

And out of the ten or so modern, more precise (less risky), genome modification methods, some are applied today to help with problems. Tomorrow they will be used for body modification. (But it is unlikely they will fix in the population.)

3 Myrs old dedicated 'engineering' on top of 4 billion years of unspecific one. That is a whole lot of capable evolution! (Which is why these new bacteria species evolve.)
rrrander
1 / 5 (1) Mar 14, 2016
Ah seems like only yesterday when they were talking about biodegradable plastic, in reality, 30 years ago. Nothing came of it. Guess why? PRICE!!!
KipHansen
not rated yet Mar 14, 2016


Well, gollygee, Mr. Kippers --everything's sunshine and moonbeams!

This research is quite interesting. When they drag nets through the water, they find micro-bits of plastics - increasing in number as the size goes down -- until a certain size below which the numbers drop to zero. The disappearing plastic had all perplexed until the discovery that microbes were eating the plastic. Like ice, small bits have a high surface area to volume ratio -- the microbes thus consumed the whole bit.

What this means is that we can not remove the plastic from the environment -- it returns to the environment naturally by becoming food for microbes. If we quit putting plastic into the sea, it will be consumed, just like oil that leaks from the sea bed.

dhogue50
not rated yet Mar 14, 2016
I can only hope that dome Bioengineer does not try to Increase the efficiency of this bacteria's biodegradation. Are we approaching an "ICE-9" moment?
Caliban
5 / 5 (1) Mar 20, 2016

What this means is that we can not remove the plastic from the environment -- it returns to the environment naturally by becoming food for microbes. If we quit putting plastic into the sea, it will be consumed, just like oil that leaks from the sea bed.


That's right, it can't be completely removed from the world ocean, because most of it is much too small.

But your claim that it is consumed and broken down by marine life is fatuous --it remains plastic in the animal's body until it dies or excretes it, just as it would in your own.

Breaking plastic into smaller and smaller pieces doesn't render it non-plastic, sub-plastic, or otherwise. It remains plastic and it remains harmful for a host of reasons.

It is not consumed and chemically degraded by bacteria as are at least some portion of oil and methane.

This is an essential fact that must be understood.
TudorCorneliu
not rated yet Apr 03, 2016
the problem is that they don't break if fast enough in a range variety of condition. so they will try probably to engineer this aspect... but this begs the question..... what will happen when they start eating the wrong PET ?! lol
KipHansen
not rated yet Apr 03, 2016
Reply to Caliban (Mar 20, 2016) ==> Yours stating "It is not consumed and chemically degraded by bacteria as are at least some portion of oil and methane.
This is an essential fact that must be understood." is essentially incorrect.

It is correct in that when an albatross scoops up a bit of plastic, the plastic passes more-or-less unaltered through the bird's digestive system and is excreted, like a marble swallowed by a human baby.

Also, plastics breaking down in the sea into smaller and smaller pieces likewise does not make them disappear.

What does make them disappear is detailed in this research: http://www.nature...191.html titled "Marine microbes digest plastic". This discovery has been followed by much more research into this topic. The bottom line is that microbes do in fact consume oceanic plastic making it "disappear".

blizzard
not rated yet May 01, 2016
What is the end product of the eaten plastic by the bacteria? So the bacteria reverses the plastic into what product please? Is this end result environmentally friendly?

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