Newly discovered bacteria can eat plastic bottles | Hacker News Reader

Newly discovered bacteria can eat plastic bottles

phys.org

97 pointsytNumbers58 comments

From another article on the same topic[1]:

>The Kyoto researchers identified the gene in the bacteria's DNA that is responsible for the PET-digesting enzyme. They then were able to manufacture more of the enzyme and then demonstrate that PET could be broken down with the enzyme alone.

Sounds like this is quite a big step forward in our ability to reduce plastics to more base elements.

Has anyone caught what the exact output of this process is? Some waste must be excreted by these microbes, right?

[1] http://phys.org/news/2016-03-plastic-munching-bacteria-fuel-...

Well if these genes exist somewhere, and we commercialize them. Is it not a matter of time until these genes become more common in bacteria in general and then we can no longer use plastics, I guess then we would have to put some antibacterial in plastics too. Like say a long time period.

I'm not a biologist, but I don't think genes are contagious

Look up horizontal transfer.

https://en.wikipedia.org/wiki/Horizontal_gene_transfer

If they confer a selective advantage, they can quickly spread through a population: https://en.wikipedia.org/wiki/Selective_sweep

The sense I have from working in environmental microbiology is absolutely not. There simply isn't that strong of a selective pressure for the degradation of plastics, especially because (a) plastics are incredibly rare compared to other microbial food sources, even in "plastic rich" places like the pacific garbage patch, and (b) it isn't clear that there is any energy advantage for producing this enzyme in most environments- I'm not even sure the end products of the reaction are used in energy production or assimilation at all. Thirdly, even if plastics were abundant and this pathway did provide a useful source of energy, it is almost certainly not as energy efficient as the common enormously successful microbial pathways for energy production and catabolism that exist when their reactants are in high abundance. Fourthly, I'm fairly sure the reaction rate is slow enough that degradation of macroscale plastics would only occur in concentrated bacterial cultures or when exposed to concentrated stock enzyme. Your iPhone case would never be at risk- I also highly, highly doubt that macroscale degradation could occur due to naturally produced enzyme alone even in soil and ocean environments, where there is rich microbial life. Fifthly, because it is a naturally occurring degradation pathway, if there were any significant evolutionary advantages these gene products would already be widespread in the microbial ocean or soil environments.

Essentially, I am almost certain that the risk of using concentrated enzyme to remove micro or milli scale environmental plastics, or even seeding local sites with cultures producing this enzyme, are 0. In reality, I don't think that there would be many plans to use this outside of bioreactors, and best case scenario it could clean up local environmental microplastics!

  > I guess then we would have to put some antibacterial in plastics too.

Maybe. It's not like plastic products have a particularly long lifetime anyway, there are plenty of things that degrade them (like sun).

So as long as the bacteria doesn't act super-quickly, I think we'll be ok.

Reminds me of this article.

Teen Decomposes Plastic Bag in Three Months: http://www.wired.com/2008/05/teen-decomposes/

I know that HN is not reddit and these sort of remarks are frowned upon, but the URL is hilarious, in a creepy way.

(Note to self: when using "talking" URLs in a future web app, use the whole article title, not just a snippet)

> Mincer said: "I don't see how microbes degrading plastics is any better than putting plastic bottles in a recycling bin so they can be melted down to make new ones."

How it's better is that recycling is really just downcycling. Recycled plastics are of worse quality and are put to inferior uses. Plastic bottles that are recycled are not only melted but also shredded. Over multiple recyclings, the shredding reduces the molecular length and therefore qualities like tensile strength. The mixing of different plastics also degrades quality.

https://en.wikipedia.org/wiki/Downcycling

So then this bacterial approach provides a potential exit path for plastic that has been recycled too many times to be of any decent use any more.

It sounds like these particular bacteria do a better job of breaking down plastic than what happens to "biodegradable" plastic when it is left out in the elements namely turning into "plastic dust" that hangs around.

Everyone seems to see this as a good thing, but think of terrible it would be if all the plastic items around you decomposed like wood. Sure, it would be beneficial for garbage and litter to "go away," but just think of how much more plastic we would need to use if every plastic item needed to be replaced every 10 years. I think it might have a significant impact on recycling as well - "rotten" plastic might be unrecylable, leading to even more use of virgin (?) plastic.

A lot of them do, if exposed to sunlight. Put a plastic water bottle or shopping bag out where it will get daily exposure to the sun. It doesn't take too long (e.g. less than a year?) before it first gets brittle and crumbly and then disintegrates completely.

Dry wood lasts a lot longer than 10 years. Presumably, dry plastic would also last a very long time.

A paint can also protect stuff for a long time.

Except "not rotting or corroding in wet conditions" is one of the reasons plastic is so useful.

People also used to use wooden boats.

Ok? They switched because plastic is a far superior material.

I never have to worry about my plastic canoe rotting, weighs half of what a wooden one does, and is more flexible when scraping rock.

We would just have to add some toxic substances to the plastic to keep the microbes down :-/

I'm a bit confused. In the article it has these 2 statements:

> "...enzyme breaks it down even further, providing the bacteria with carbon and energy to grow."

> "I don't see how microbes degrading plastics is any better than putting plastic bottles in a recycling bin so they can be melted down to make new ones."

Is it degrading it to basic elements such as carbon, or is the bacteria just breaking the plastic down into smaller, microscopic pieces? If the bacteria actually breaks the plastic down to base components, then that is undoubtedly different than melting and recycling the plastic. There could be incubation centers that focus on reproducing this bacteria at mass scale and then releasing them into dumps to break down the plastic that is mixed in with the garbage.

What's the issue with having plastic in dumps? IMO, they dumps are one of the few carbon sinks humans actually use. Releasing that carbon seems to be a waste.

We can't keep creating new garbage dumps, eventually we'll run out of land. If we can decompose plastic, let all the organics and paper based garbage decompose, then you have a lot more space for new garbage to be added.

I mean you're technically correct, but how long will that take? The earth is large and we have not covered even a fraction of 1% of it with landfill. It's unlikely that we'd actually run out of space in practice, it'd take thousands of years. Not that I condone the idea.

Not really, today's dumps are tomorrows mines. If we really don't want to keep this stuff over a very long time scale we could use a seduction zone and send our junk into earth mantle.

PS: Trash is matter, to generate cubic miles of the stuff we need cubic miles of raw materials.

Eventually the fusion process in the sun stops too.

I can't believe people are arguing for more landfill. Its inevitable that its going to happen, but that doesn't mean we should shouldn't try and minimize it. As we know lots of it doesn't end up in landfill.

http://www.theguardian.com/business/2016/jan/19/more-plastic...

Carbon Sequestration is a landfill. https://en.wikipedia.org/wiki/Carbon_sequestration

Plastic is Carbon, hydrogen, and possibly (oxygen, sulfur, or nitrogen) ex: C4H3NO2. Breaking plastic down just gives that same stuff back.

IMO, Sequestration is generally a bad idea, but if it's already underground then releasing that carbon for little gain seems pointless. At least when we burn trash we get some energy out of it.

They mean landfill as in a garbage dump: https://www.google.com/search?q=landfill&espv=2&rlz=1CAZZAD_...

There are many forms of carbon sequestration, but this is the first I've seen someone try to redefine it all as garbage. There is more than just plastic (carbon) in a landfill, some of which takes centuries to degrade.

According to another piece I saw on this [0], the reaction products are ethylene glycol and terephthalic acid. Both of those are useful industrial chemicals, though not things you'd want to eat yourself.

ETA: The Gizmag article characterizes these chemicals as "environmentally harmless", which might be a slight exaggeration. I wouldn't be surprised if terephthalic acid turned out to be an endocrine disruptor, given its benzene ring. But neither chemical is acutely toxic.

[0] http://www.gizmag.com/pet-enzyme-plastic-waste/42262/

Here is a recent study showing estrogenic effect from terephthalic acid (TPA)

http://m.carcin.oxfordjournals.org/content/36/1/168

> putting plastic bottles in a recycling bin so they can be melted down to make new ones

This can't be done with the type of plastic used to make bottles. Plastic bottles are either reused as-is, or "downcycled" to lower grade plastic used for different products, like fleece clothing or fiberboards.

http://www.greenhome.com/blog/what-is-downcycling

Would it be possible to use a spray rich in these bacteria (and maybe other nutrients?) onto that island of plastic at sea?

If we're thinking about the same thing - that 'island of plastic' turned out to be incredibly diffuse - something like a few particles of plastic per cubic meter.

The article mentions the bacteria works at "a steady 86 degrees Fahrenheit." It may work slower or not at all at Pacific Ocean temperatures.

As a result of this article, I'm sure we'll be seeing a lot of groups engineering this bacteria's systems into something that could survive and grow at lower temperatures. Or maybe they'll try to encapsulate the two enzymes in nanoparticles.

may work in a animals stomache?

Exactly. They found it living in plastic eating bugs and it will do good for say - sea turtles, which mistakenly eat plastic and choke. Just force the turtles to ingest a pill with Ideonella Sakaiensis and if they'll be lucky - they'll get new symbiotic pals!

or even on the products in Wal-Mart

Anyone else concerned that by helping this new bacteria thrive it will set off a series of unforeseen side effects?

My username is a reference to Project Wildfire from "The Andromeda Strain". In the novel, Andromeda mutates into something that can consume rubber -- the same materials used throughout the world as seals against contagion.

So, yeah, if life imitates art it could get pretty interesting.

Can't forget this classic work of speculative fiction either: http://www.goodreads.com/book/show/2368220.Mutant_59

In the Coburg Street control room of the London Underground system, there was a full emergency... In a dozen tunnels, trains ground down to a halt. Hordes of terrified commuters made their way anxiously along dark, musty tunnels to the lights and safety of the next station. There were minor explosions, fires, and the failure of a million wires and cables. As the dissolution of plastic proceeded and accelerated in rate, the elegant order of the system gradually turned into complete chaos...

I'm glad I'm not the only person who remembers that one.

Very much so. One of the things that makes plastics so useful is their tendency to not rot away in certain environmental conditions.

We just need a bacteria that eats the plastic-eating bacteria.

Horizontal gene transfer is one of the issues brought up by researchers who discovered the plastic eating fungus Pestalotiopsis Microspora

What are you talking about? So far this was just a discovery of an already existing bacterium. They identified it and studied it a little bit. I find no plans for "helping this new bacteria thrive" anywhere in the article.

I just finished reading Ringworld for the first time and had exactly the same thought.

Doesn't really say what's left over after the plastic gets broken down.

CO2 is a safe bet.

Sounds like a great discovery until you get to the end of the article

> 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 plastic bottles in a recycling bin so they can be melted down to make new ones."

Well,

The problem with recycling is that it's economics hinges on the price of oil. The recycling industry where I am (Northern California) has collapsed with the decline in the price of oil[1]. It would be better to use regulation to force recycling but in the absence of that a way to simply dispose of plastic bottles seems excellent.

It would nice if the bacteria would be put in dormant form on the bottle labels, making bottles pseudo-biodegradable.

[1] http://www.pressdemocrat.com/news/5288760-181/recycling-cent...

> I don't see how microbes degrading plastics is any better than putting plastic bottles in a recycling bin so they can be melted down to make new ones."

You don't have to waste money and energy sorting bottles out of the trash if you can just dump a bunch of this bacteria in your landfill.

The comment you are responding was what the scientists in the article concluded, not something I was saying.

My first thought when I read this headline was, "Thank God. We're going to need this in weaponized form when the robots take over." Next up, bacteria that eats carbon fiber...

Reminds me a bit of one of the plot points of the Ringworld novels. Our world runs on plastic; I wonder what would happen if a massively successful plastic-eating bacteria took off.

It's been a very long time, but I guess this 1979 Judge Dredd story made an impression on me as a kid because it was immediately what came to mind: http://dreddalert.blogspot.co.uk/2014/01/judge-dredd-great-p...

When trying to re-read Ringworld, I mis-remembered it as DiscWorld, and then entered the bizarre mind of Terry Pratchett. Best mistake I ever made.

I also seem to recall a part of "Andromeda Strain" where bacteria were eating anything made of rubber?

A microbe species from a hitherto undiscovered kingdom, and a synthetic compound used for many of the same applications as rubber. But otherwise, yes :).

Jeff Goldblum has something to say.

"Life, uh, always finds a way"

The danger of humans is whether we give life enough time.

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