These bacteria eat plastic Morgan Vague
Transcriber: Ivana Korom
Reviewer: Joanna Pietrulewicz
Plastics: you know about them,
you may not love them,
but chances are
you use them every single day.
By 2050, researchers estimate
that there will be more plastic
in the ocean than fish.
Despite our best efforts,
only nine percent of all plastic we use
winds up being recycled.
And even worse,
plastic is incredibly tough and durable
and researchers estimate
that it can take anywhere
from 500 to 5,000 years
to fully break down.
It leaches harmful chemical contaminants
into our oceans, our soil,
our food, our water, and into us.
So how did we wind up
with so much plastic waste?
Well, it’s simple.
Plastic is cheap, durable,
adaptable, and it’s everywhere.
But the good news is
there’s something else that’s cheap,
durable, adaptable and everywhere.
And my research shows
it may even be able to help us
with our plastic pollution problem.
I’m talking about bacteria.
Bacteria are microscopic living beings
invisible to the naked eye
that live everywhere,
in all sorts of diverse
and extreme environments,
from the human gut, to soil, to skin,
to vents in the ocean floor, reaching
temperatures of 700 degrees Fahrenheit.
Bacteria live everywhere,
in all sorts of diverse
and extreme environments.
And as such, they have to get
pretty creative with their food sources.
There’s also a lot of them.
Researchers estimate that there are
roughly five million trillion trillion –
that’s a five with 30 zeros after it –
bacteria on the planet.
Now, considering that we humans produce
300 million tons of new plastic each year,
I’d say that our plastic numbers
are looking pretty
comparable to bacteria’s.
So, after noticing this
and after learning
about all of the creative ways
that bacteria find food,
I started to think:
could bacteria in
plastic-polluted environments
have figured out
how to use plastic for food?
Well, this is the question that I decided
to pursue a couple of years ago.
Now, fortunately for me,
I’m from one of the most
polluted cities in America,
Houston, Texas.
(Laughs)
In my hometown alone,
there are seven EPA-designated
Superfund sites.
These are sites that are so polluted,
that the government has deemed
their cleanup a national priority.
So I decided to trek around to these sites
and collect soil samples
teeming with bacteria.
I started toying with a protocol,
which is fancy science talk for a recipe.
And what I was trying to cook up
was a carbon-free media,
or a food-free environment.
An environment without the usual
carbons, or food,
that bacteria, like us humans,
need to live.
Now, in this environment,
I would provide my bacteria
with a sole carbon, or food, source.
I would feed my bacteria
polyethylene terephthalate,
or PET plastic.
PET plastic is the most widely produced
plastic in the world.
It’s used in all sorts
of food and drink containers,
with the most notorious example
being plastic water bottles,
of which we humans currently go through
at a rate of one million per minute.
So, what I would be doing,
is essentially putting my bacteria
on a forced diet of PET plastic
and seeing which, if any,
might survive or, hopefully, thrive.
See, this type of experiment
would act as a screen
for bacteria that had adapted
to their plastic-polluted environment
and evolved the incredibly cool
ability to eat PET plastic.
And using this screen,
I was able to find some bacteria
that had done just that.
These bacteria had figured out
how to eat PET plastic.
So how do these bacteria do this?
Well, it’s actually pretty simple.
Just as we humans digest carbon or food
into chunks of sugar
that we then use for energy,
so too do my bacteria.
My bacteria, however, have figured out
how to do this digestion process
to big, tough, durable PET plastic.
Now, to do this,
my bacteria use a special version
of what’s called an enzyme.
Now, enzymes are simply compounds
that exist in all living things.
There are many different types of enzymes,
but basically, they make
processes go forward,
such as the digestion of food into energy.
For instance, we humans
have an enzyme called an amylase
that helps us digest
complex starches, such as bread,
into small chunks of sugar
that we can then use for energy.
Now, my bacteria have
a special enzyme called a lipase
that binds to big, tough,
durable PET plastic
and helps break it
into small chunks of sugar
that my bacteria can then use for energy.
So basically,
PET plastic goes from being
a big, tough, long-lasting pollutant
to a tasty meal for my bacteria.
Sounds pretty cool, right?
And I think, given the current scope
of our plastic pollution problem,
I think it sounds pretty useful.
The statistics I shared with you
on just how much plastic waste
has accumulated on our planet
are daunting.
They’re scary.
And I think they highlight
that while reducing, reusing
and recycling are important,
they alone are not going to be enough
to solve this problem.
And this is where I think bacteria
might be able to help us out.
But I do understand
why the concept of bacterial help
might make some people a little nervous.
After all, if plastic is everywhere
and these bacteria eat plastic,
isn’t there a risk of these bacteria
getting out in the environment
and wreaking havoc?
Well, the short answer is no,
and I’ll tell you why.
These bacteria are already
in the environment.
The bacteria in my research
are not genetically modified frankenbugs.
These are naturally occurring bacteria
that have simply adapted
to their plastic-polluted environment
and evolved the incredibly gnarly
ability to eat PET plastic.
So the process of bacteria eating plastic
is actually a natural one.
But it’s an incredibly slow process.
And there remains a lot of work to be done
to figure out how to speed up
this process to a useful pace.
My research is currently
looking at ways of doing this
through a series of UV,
or ultraviolet, pretreatments,
which basically means
we blast PET plastic with sunlight.
We do this because sunlight
acts a bit like tenderizer on a steak,
turning the big, tough,
durable bonds in PET plastic
a bit softer and a bit easier
for my bacteria to chew on.
Ultimately, what my research hopes to do
is create an industrial-scale
contained carbon-free system,
similar to a compost heap,
where these bacteria can thrive
in a contained system,
where their sole food source
is PET plastic waste.
Imagine one day being able to dispose
of all of your plastic waste
in a bin at the curb
that you knew was bound for a dedicated
bacteria-powered plastic waste facility.
I think with some hard work
this is an achievable reality.
Plastic-eating bacteria is not a cure-all.
But given the current statistics,
it’s clear that we humans,
we could use a little help
with this problem.
Because people,
we possess a pressing problem
of plastic pollution.
And bacteria might be
a really important part of the solution.
Thank you.
(Applause)