Bugs are evolving to eat plastic, study finds

achenet | 414 points

"The first bug that eats plastic was discovered in a Japanese waste dump in 2016. Scientists then tweaked it in 2018 to try to learn more about how it evolved, but inadvertently created an enzyme that was even better at breaking down plastic bottles. Further tweaks in 2020 increased the speed of degradation sixfold.

Another mutant enzyme was created in 2020 by the company Carbios that breaks down plastic bottles for recycling in hours. German scientists have also discovered a bacterium that feeds on the toxic plastic polyurethane, which is usually dumped in landfills."

Would love to see the timeline and capacity plotted on a chart. I wonder how much we need to make it practical. 6x increase in 2 years but did we go from decades to years?

Hours on bottles sounds like we are getting there in speed but how much bacteria, and how quickly do they multiply and what do they do once they are done? I am asking because breaking bottles down in hours doesn't sound "promising", it sounds like we are there. Just pour that on the plastic island in the ocean! If we cannot, there must be something else going on that prevents us.

omarhaneef | 2 years ago

> “The next step would be to test the most promising enzyme candidates in the lab to closely investigate their properties and the rate of plastic degradation they can achieve,” said Zelezniak. “From there you could engineer microbial communities with targeted degrading functions for specific polymer types.”

John Todd has been working on ecologies (in a vat) that can process waste for over fifty years now. Among his accomplishments was developing an ecology that can break down DDT in a matter of weeks, instead of years. The main thing he does is drawing from all five of the major kingdoms together, and have them self-organize around the waste being processed. (https://www.toddecological.com/about)

With the self-organization, it's not always necessary to model and engineer everything.

hosh | 2 years ago

Imagine this:

Monsanto patents a genetically modified bug that eats plastic, sells it to governments and recycling plants.

Then, once it gets into nature and it starts eating things that isn’t trash, monsanto patents a series of plastics that is resistant to this bug.

Increasing the price of plastic bags by 10x.

Repeat this whole cycle over and over again. It becomes an arms race of patented bug, then patented plastic.

shnp | 2 years ago

This study from 2013 was a revelation about how plastic is colonized and metabolized (!) in the ocean:

"Life in the “Plastisphere”: Microbial Communities on Plastic Marine Debris"

Full PDF: https://eportfolios.macaulay.cuny.edu/branco2014/files/2014/...

First part of abstract:

Plastics are the most abundant form of marine debris, with global production rising and documented impacts in some marine environments, but the influence of plastic on open ocean ecosystems is poorly understood, particularly for microbial communities. Plastic marine debris (PMD) collected at multiple locations in the North Atlantic was analyzed with scanning electron microscopy (SEM) and next-generation sequencing to characterize the attached microbial communities. We unveiled a diverse microbial community of heterotrophs, autotrophs, predators, and symbionts, a community we refer to as the “Plastisphere”. Pits visualized in the PMD surface conformed to bacterial shapes suggesting active hydrolysis of the hydrocarbon polymer. Small-subunit rRNA gene surveys identified several hydrocarbon-degrading bacteria, supporting the possibility that microbes play a role in degrading PMD. ...

The pictures are striking. It really looks like the plastic is being eaten. The 2013 study only covered floating debris, though. High density plastics that sink to the benthic zone arrive in an environment with much slower biological turnover and different organisms than the near-surface environment. This current study is interesting in that it sampled enzymes from different ocean depths, not just the surface, and found elevated degradation signals even at depth.

philipkglass | 2 years ago

There’s a theory that most coal comes from a period after plants evolved lignin (the substance that makes wood woody) but before bacteria and fungi evolved the enzymes to break lignin down. Perhaps something similar will happen with plastic.

elil17 | 2 years ago

In my view this is the most likely way microplastics will be removed from the ecosystem, as there is neither the collective will to clean it up nor will there likely be a way to clean it up through human intervention within a reasonable timeframe.

In a way, plastic pollution is like a rapidly growing and untapped market that could be taken advantage of by microbes. A whole microbial ‘industry’ could take hold to process the various types of plastics along with the waste products that are generated when broken down by other microbes.

surfpel | 2 years ago

I really don't like plastic. I prefer to avoid it for any purchase where there is a practical non-plastic alternative. But, I have to say, if we had a bacteria that could rapidly digest most plastics, and spread "in the wild", it could have some catastrophic effects on our world's economy. Imagine everything in the public infrastructure that uses plastic, rotting within a year's time. It could be apocalyptic.

rossdavidh | 2 years ago

It's be hilarious when these become widespread, and plastic will start rotting like wood.

pornel | 2 years ago

Lots of species evolved to survive the cretaceous paleogene extinction event, it still doesn't mean you should go on throwing asteroids on people because eventually some mouse will survive and reproduce to eat the plant who survived and reproduced.

chaosbolt | 2 years ago
markm248 | 2 years ago

This article doesn't address microplastics. These enzymes degrade plastics, but what is left over? Does the problem of microplastics still occur such that the plastics only degrade to a certain size?

bmitc | 2 years ago

The earth is going to return petroleum to the biosphere, and humans are a part of that process. We are the bacteria that eats oil.

The utility of plastic as a material that is very durable is a temporary state of affairs. As more of these microbes evolve traits that allow them to metabolize it, the utility of plastic will wane. It's primary selling point, as well as it's primary detrimental trait, is it's ability to withstand decomposition.

Climate change due to carbon dioxide is a part of this process. Returning sequestered carbon to the carbon cycle necessarily causes disturbances in balance for a time. In the end, what you wind up with is more biomass, or more specifically, biomass that once existed that is now being reintroduced.

betwixthewires | 2 years ago

Feeling somewhat vindicated vis-à-vis my middle school biology teacher after being belittled for asking whether this would happen.

t_mann | 2 years ago

Article is apparently about microbes and not insects (lol.) The author also uses the word "evolve" but is this really correct? Doesn't it literally take millions of years for evolutionary changes? IMO: what's happening is they're finding microbes that already had the ability to break-down plastic rather than microbes literally changing forms to be able to break-down plastic? Or can these kind of environmental changes really happen that fast?

Uptrenda | 2 years ago

The coal formations we exploit today were formed during 60 million years period in between the evolution of wood and bark, and the evolution of fungi and bacteria that could break them down.

I wonder if wood had other noxious effects on biology back then as our plastics do today. Perhaps not.

forgetfulness | 2 years ago

The plot of a scifi book I read some years ago was a group of people wanted to destroy mankind but leave the Earth intact.

Their method was to unleash a virus that ate plastic.

Civilization ended because of our reliance on plastic.

WalterBright | 2 years ago

The Guardian's version of the article contains an update correcting a misattribution. The study was published in mBio: https://www.theguardian.com/environment/2021/dec/14/bugs-acr...

Just an FYI for anyone who's interested in tracking down the actual academic paper.

ABCLAW | 2 years ago

Was a bit disappointed by the absence of insects. Maybe fix the title to "Microbes" rather than "Bugs".

tomxor | 2 years ago

In 2001 scientists also discovered fungus that grows on compact disk's aluminium and polycarbonate layers.

https://www.nature.com/articles/news010628-11

Lutzb | 2 years ago

While I’m happy to hear about good developments related with plastic waste, am I the only one worried about the implications of a plastic eating bug? We sort of depend on how he durability of plastic in our modern world. Or is this simply a non-issue?

dwg | 2 years ago

> The first bug that eats plastic was discovered in a Japanese waste dump in 2016.

That wasn't a bug! It was the bacteria Ideonella sakaiensis, if my Google-fu serves me right.

Maybe the whole article (meaning the title as well) is off?

aliswe | 2 years ago

> The first bug that eats plastic was discovered in a Japanese waste dump in 2016.

In 2009, a Taiwanese high-school student (Tseng I-ching) discovered a bacterium that decomposes polystyrene [0]. I think she deserves credit for starting this field of research.

[0] https://taiwantoday.tw/news.php?unit=10,23,45,10&post=15307

mleonhard | 2 years ago

At some point bugs will evolve to eat electricity directly.

After all, that's what the electron transport chain does in respiration. So just cut the food middleman.

323 | 2 years ago

Does this mean our trash has been biodegradable this whole time and that 3000yr estimates were not accounting for evolution?

headelf | 2 years ago

It's fascinating that evolution can occur so rapidly. Perhaps human genome editing will one day be required to help cope with novel externalities. Or, in some cases, maybe we'll get by with additional help from new enzymes.

I had not considered the evolution of new biological functions may not require the death of the organism.

windows2020 | 2 years ago

I spent a few minutes googling around expecting the researchers or funding to have heavy ties to the fossil fuel industry. This seems like something created to make people feel less guilty and reduce social pressure on using less plastic.

But I didn't really find anything, so maybe a tiny bit of optimism is allowed.

1270018080 | 2 years ago

Given the amount of microplastics humans consume, could humans one day evolve to eat and digest plastic?

xwdv | 2 years ago

I believe this is how The Andromeda Strain escaped from the lab. Time to stock up on Sterno.

karaterobot | 2 years ago

We’re eating plastic too. It’s just harmful. I wonder if we will ever encounter a gene expression where it isn’t.

What a neat idea. Maybe there is a future where plastic vitamins intentionally trigger desired hormonal responses.

andrewmcwatters | 2 years ago

I think it's more likely that the fungi in the bugs' digestive system have already had the ability to break down plastic, only it was latent and unnecessary until recently.

triyambakam | 2 years ago

Paraphrasing title, bugs are evolving faster than humans… :-\

obert | 2 years ago

Microorganisms that eat plastics will be great at first, until hospitals see breakouts of them. At least with insects, outbreaks are far easier to prevent

gentleman11 | 2 years ago

Well, our world is made of plastic. If bacteria will eat plastic, we would have to make other uneatable plastic.

funny_falcon | 2 years ago

At this point humans are behind the curve. We should take this as a sign to adapt.

hawksprite | 2 years ago

Bugs eat plastic, people eat bugs, people make plastic. It’s the circle of life.

throwaway1777 | 2 years ago

Awesome, proof once more man is not at the pinnacle of evolution.

MomoXenosaga | 2 years ago

Great. Now all we need is one that breathes in CO2.

cutler | 2 years ago

I for one welcome our plastic eating overlords.

fnordpiglet | 2 years ago

You are exactly mentioning it

topaid | 2 years ago

maybe we can engineer humans to eat plastic

andsoitis | 2 years ago

mind the gray goo please.

sunjester | 2 years ago

Living in the Plastic Age.

almost_usual | 2 years ago

Annoying this uses the word "bugs," which is commonly used to mean insects; the article actually discusses only "microbes" and "bacteria." These can be called bugs colloquially, but why not just use the word "microbes" in the title?

This might seem pedantic, but it is not a new result to have find microbes that can digest plastics; AFAIK no "bugs" (insects or other creepy-crawlies) have gained such abilities yet, so the result is a very clickbaity headline.

alanh | 2 years ago