These worms are literally eating their way
out of this plastic bag.
But not only can they eat it,
it's actually good for the planet.
So if they can biodegrade plastic,
could they be the answer to our planet's massive plastic problem?
Biology has found a way, to some extent, to deal with this.
Because the latest science on this is mind-blowing.
Not only might we make plastic biodegradable,
we might even one day be eating vanilla ice cream.
from recycled plastic and E. coli.
Yes. I mean, it's chemically identical.
Yeah...
So we'll get back to that in a minute.
Let's start with the worms.
These little creatures are waxworms.
Dr Federica Bertocchini is a molecular biologist, and she first witnessed this phenomenon
when she chucked a bunch of waxworms in a plastic bag as a hobby side project because...
Well, who doesn't?
I bumped into the waxworm accidentally
because at that time I was a beekeeper.
Because they live in the beehives.
They are considered plagues by beekeepers.
So I start cleaning my beehive, putting the worms in a plastic bag,
and within a short time I realised that they were producing holes.
The plastic started to degrade almost as soon as it touched the worms' mouths.
So we thought, OK, maybe something coming out of the mouth.
So we start collecting this liquid coming out.
We call it saliva, but it's the liquid coming out of the mouth.
So in this saliva, we found two enzymes that can reproduce the effect of the saliva, meaning oxidising polyethylene.
And it takes a few hours, at room temperature, in a watery solution.
And the amazing thing is that the worms can even digest the plastic, breaking it down into something useful for the worm.
The worm itself, when it eats the plastic and start breaking it down, its guts react almost as if it was eating normal food.
So that means that there's something happening with the physiology of the animal
that extracts something out of this plastic biodegradation. And it just continues as if it were a normal diet.
That's Dr Chris LeMoine who, inspired by Federica's findings, also began looking into these worms.
We found that the plastic allowed them to still retain all their fat and presumably continue with their life cycle.
Basically, these worms are fattening themselves up by whatever means necessary before they turn into moths,
by which point they don't eat again, only reproduce.
I always call them bags of gonads that can fly because that's all they do.
So there's a race under way to figure out just how this mechanism works.
That's the million or trillion dollar question, because once we figure that out,
that's a trillion dollars worth of plastic we can degrade.
Because as cool as the waxworms are, this is really about the specific combination of bacteria and enzymes
that can break down plastic,
something that's exceptionally rare in nature.
So why is it so rare? Why is plastic so hard to break down?
Well, in nature, most things decompose because bacteria breaks down the chemical bonds that hold a substance together.
These enzymes and bacteria have evolved over millennia to break down whatever it finds in front of it.
Then plastic comes along.
Here's a scene that has long since ceased causing any surprise: Dishes that bounce when they drop to the floor.
Nowadays it gets a bad rep, but it's a total game changer for humanity.
But nature has never experienced it before.
Plastics are made up of long chains of polymers with very strong bonds.
And one of the keys to breaking these bonds is through oxidation.
That's what the worms appear to be doing with their saliva, introducing oxygen molecules to the plastic.
And this is sometimes achieved in the environment through light, for example, high temperature.
And this is the bottleneck. It takes a while because the environment has its own timing.
So the worms, what they do is just introduce a molecule of oxygen. So in a few hours instead of months, or years, or whatever.
So this is, it's a way to overcome the bottleneck of this reaction.
So what's next? Unleash the worms?
No, that would be a terrible idea.
Remember this?
They are considered plagues by beekeepers.
But even sticking just to plastic, the process is still way too slow to realistically solve our plastic crisis any time soon.
So stand down, waxworm armada.
The real stars of this, though, are the enzymes.
If the researchers can identify them and scale them up, there's a chance that in the future this could be one of the solutions.
It will take a lot of cash.
But now scientists are looking for similar enzymes in all sorts of other places.
Superworms, too. So anything that has a worm in it, it seems to be prone to eat plastic.
In fact, over 30,000 enzymes have been identified, capable of digesting 10 different types of plastics.
One bacteria found in cow stomachs can be used to digest polyester.
But the one that's getting everyone really excited is a bacteria called Ideonella sakaiensis,
and especially its enzyme PETase.
Plastics waste in general, more specifically PET,
has infiltrated our environment
and biology has found a way to some extent, to deal with this over time.
There was a discovery outside of Japan where they had found that microbes began to colonise on parts of a water bottle.
Cells were actually living and maybe even surviving off the carbon within that plastic.
We can take this enzyme out of the cell and we can begin to engineer that enzyme even further
to be able to have better activity directly on plastic waste.
PET plastic that would take centuries to break down in nature, PETase can break down in a matter of days,
but it doesn't solve our plastic problem.
Not yet, anyway.
To have any real impact at scale, we need to turbocharge how quickly it works.
And that's exactly what Hal's team has done. And they name this really fast version of PETase...
FAST-PETase.
They did this using AI, essentially by using a vast database of all known enzymes in the natural world
and then running simulations about which combinations and mutations would speed up the process,
kind of like a form of computerised, accelerated evolution.
Machine learning approach really is, it's rapid evolution to some extent on there, but at the same time, it's guided by observation.
We saw that this enzyme was not very stable overall and used a machine learning type approach
to figure out which point mutations would make this enzyme more stable and found a couple of mutations
that really both increased the stability significantly,
but then also gave rise to a significant increase in the activity in this enzyme on plastic.
This cutting edge technology opens up a whole new frontier of scientific possibility, and the team aren't done yet.
Thinking about trying to clean up plastic that's actually in the environment,
those applications don't have the benefit of being able to control the temperature and PH very well.
So having an enzyme that ultimately is flexible enough to work in a variety of different conditions is extremely valuable.
Once PET plastic is broken down into its component parts, terapthalic acid and ethylene glycol,
it can then be recycled into new plastic,
but it doesn't necessarily have to be plastic.
In theory, it could be used to make something better,
like this.
Well, sort of, because a team of scientists in Edinburgh have found a way to turn plastic into vanillin.
That's the central ingredient in vanilla.
And they did it using E. coli.
Sounds delicious...
For me and for anyone who's thinking about a nice vanilla ice cream. What are we not understanding about that?
We get asked this question a lot.
Yes. I mean, it's chemically identical.
OK. Forgive me if the next part ruins vanilla for you.
So vanillin is a component that's derived from from oil that we pump out of the ground.
It's the same feedstock that we use to make petrol that we use in our cars.
So we, in essence, took one of those enzymes that had been reported to do the initial depolymerisation
and then took the mixture of terapthalic acid and ethylene glycol that you get from that
and simply just fed it to our E. coli.
But the way that I think about it is, yes, this compound is coming from plastic waste and yes, it's coming from a bacteria.
But I think we as a society are OK with eating food that has oil in it.
Vanillin is derived from oil. So why wouldn't we be OK with having a bacterium produce that for us?
Now, these guys aren't really trying to sell you vanilla ice cream.
They're more interested in upcycling recycled plastic.
There's recycling plastics into more plastics, and then there's upcycling plastics into other compounds.
The issues at the moment currently with that approach is that when you subsequently recycle plastic into other plastics,
the value of that plastic and the quality of that plastic actually diminishes.
So you you enter into this downcycling approach that does solve the problem in the short term,
but it ultimately generates the same waste.
What we think is quite interesting about upcycling plastic is you re-enter that carbon back into the chemicals economy
as something that's higher value.
Vanillin is not the only product that we can make from plastic.
The molecules that you get when you depolymerise PET are actually intermediates
en route to a huge number of industrial products that we rely on nowadays.
One of the most interesting ones that we're focusing on right now is pharmaceutical intermediates.
You can take PET plastic waste and turn it into pharmaceutical compounds.
So taking something that's actually damaging the environment and turn it into a source of human medicine.
So medication,
other flavouring compounds,
materials for your clothing,
cosmetics,
it's quite staggering.
I think this is only really the beginning of what could be possible in the area of plastics upcycling.
I think that very much is the case.
So worms themselves aren't going to eat all our troubles away.
But the science going on around this is genuinely exciting,
and it's all thanks to nature for providing the inspiration.