All language subtitles for The.Magic.of.Mushrooms.2014.1080p.WEBRip.x264-CBFM

Of all life on Earth, there's
something more mysterious

yet more vital to our
survival than anything else.

Its birth is violent.

Much of its life
is hidden underground.

And only at the end of its life
cycle does it reveal its identity.

The mushroom.

I'm Professor Richard Fortey.

'I've been fascinated by
mushrooms all my life.'

Nice find.

'I love to collect and study them.'

Many people think of mushrooms
just as something to eat,

or maybe as decoration
in folk tales.

But nothing could be
further from the truth.

They have a secret life so magical,

so weird,

that it defies imagination,

and I'm going to reveal it
as never before.

I've set up my own lab to unlock
the mysteries of mushrooms.

Oh, look at that!

They're like geysers.

I'll discover their
astonishing powers.

What makes them the fastest...

the largest...

..and some of the deadliest
living things on the planet.

Half a cap will kill you and
kill you slowly and painfully.

And I'll meet the people turning
those powers to our advantage

to create new medicines

and new materials.

The innovation we have here is
the future of energy production

and even devices and products
like your iPhone.

To discover what gives mushrooms
their extraordinary abilities,

I'm going to follow their story
from birth, through life, to death.

A story so strange
it seems almost alien,

yet it will reveal why mushrooms
are crucial to all life on Earth,

and why they have a powerful
connection to you and me.

The only place many of us
encounter mushrooms is here.

Cultivated edible
varieties like these,

are all most of us think about
when it comes to mushrooms.

We Brits can't get enough.

It's a multimillion pound
business in the UK.

But there's so much more
to mushrooms

than this fine example
in the fresh food counter.

This mushroom is just one species
from an enormous kingdom,

the kingdom of the fungi...

..and fungi are hidden away
in all kinds of food products

in this supermarket
in ways you wouldn't expect.

Look hard enough and
every aisle reveals evidence

of how fungi underpin modern living.

Cheese.

My favourite Stilton cheese,
well, it's blue,

and the blue is a fungus.

A lot of fizzy drinks
have citric acid in them,

and that's produced by a fungus
called Aspergillus niger

in huge quantities.

Many detergents also contain
citric acid, just like fizzy drinks.

Ah, here's soy sauce, bread,

Quorn, chocolate, fruit juices.

Well, sometimes they
have a bitter taste,

which can be removed
by another fungus.

Salmon, red salmon.

The red colour, I'm afraid,

is sometimes due to
a fungus called Phaffia.

Some of the protein in pet foods,

which keeps your animals healthy
is actually produced by fungi.

And, of course, booze.

The fermenting activity
of Saccharomyces,

turning sugars into alcohol.

Clearly, our supermarket shop just
wouldn't be the same without fungi.

They're hidden away in all
sorts of ways in the products.

They must have a series of special
biochemical tricks up their sleeve.

But how exactly is it that
they seem to turn up everywhere

and affect so many
parts of our lives?

To begin to answer that question,
I'm going to a place

where I encounter fungi
in all their forms.

Head out into any woodland like
this one in the Scottish Borders,

and if you look hard enough,

you'll start finding them
everywhere.

To me, they're fascinating.

Some may think they look like
any other plant,

but in fact, they're a different
organism altogether.

Fungi evolved as a kingdom
in their own right,

distinct from plants and animals,

over one and a half
billion years ago.

It's thought that in variety,

they outnumber plants
by at least ten to one.

And searching for them
is my favourite pastime.

Some people might think of autumn
as a rather gloomy time of year,

but for me, it's pure joy.

I can take my basket,
I can go into the woods...

..and I can do my mushroom foraying.

I've been doing it for decades.

What's the thrill of it?

Well, to the left of the path,
to the right of the path,

dozens of different kinds
of fungi are erupting.

But, I suppose, the most
primeval feeling, the basic one,

is still the thrill of discovery,
the thrill of the chase.

You may not realise that what
we call the mushroom is, in fact,

just one type of fungus.

It's the form that we
are most familiar with

and it's certainly
the easiest to recognise.

The head of a mushroom is its cap.

And many have a stalk.

Look underneath the cap,

and you'll often find a set of
sharp ridges known as gills.

Ah-ha!

Well, now, this is, of course,
the archetypal mushroom.

It's the one that
the gnomes sit on top of.

It's the fly agaric.

I can see other species
really, really close to hand.

This is the king of the
edible mushrooms, the cep,

the penny bun,

porcini.

The fact that it's got
so many names is a measure

of just how highly regarded
it is as an edible fungus.

It's one of the best.

'But as well as the
quintessential mushroom...'

Bit hazardous.

'..if you look a little harder,
you'll find a host of other fungi

'that don't look like
mushrooms at all.'

Ah, well, now, here's something
completely different.

Perhaps doesn't look like a fungus
at first sight to people.

It's one of the coral fungi.

This is an ear fungus.

They're still fungi but they're
very, very different sort of fungi.

Yellow brain fungus.

Doesn't look like anything from
this Earth, really, does it?

It's the beefsteak fungus.

And you can see why -
it looks a bit like raw liver.

'In fact, this organism can take
so many weird and wonderful forms,

'knowing what it is
you're looking at

'can sometimes be a challenge, even
for an experienced forayer like me.'

Wow, now, that is
something really weird.

I'm not quite sure what's going on.

It's absolutely extraordinary.
That's one coming back to the lab.

Almost every foray I go on,
I find something new and intriguing.

Time to take a closer look
at exactly what's in my basket.

This is our specially-built
mushroom lab

where I'll be unlocking
the mysteries of fungi

with the help of mycologist
Dr Patrick Hickey.

Well, this is quite
a set-up you've got here.

Their first secret
is their identity.

So here we are with our haul
back from the woods,

and what a variety
we've got in the basket.

Of course, we notice things
like the colour, of course.

The smell.

Oh, yeah, that's got a really sweet
smell to it, very sweet odour.

So fungus identification
uses all your senses.

It's a very sensory experience.

But there's another way
we can really narrow down

the mystery of a mushroom
and positively identify it

and that's by doing something
called a spore print.

Every mushroom has
its own unique spore print

and to do a spore print,
we cut the stem off,

and then place the cap
onto a piece of paper

and just leave it for a few hours.

When you come back
and lift it up,

you'll see the mushroom has
deposited a layer of spores

and they look just like fingerprints.

It's a bit like taking a
fingerprint from a mushroom.

These spores are like
the seeds of a mushroom

and the patterns they create
can reveal some surprises,

even when two mushrooms
appear to look the same.

So here we've got
two similar looking...

Almost the same, yeah.
..white mushrooms,

but reveal the spores -
one's startlingly white

and the other's very black.

Yeah, it's a key in the
identification of the mushroom.

So we have such
a variety of colours.

We've got a sort of purple here.

We've got cream, we've got white,

very pure white, rust brown,
even pinkish. Yeah.

And I have to say what a beautiful
pattern it makes too.

I mean, aesthetically,
extremely pleasing.

They're wonderful. They're just
like the silhouettes of a mushroom,

and that colour of the spore print
is unique to that type of mushroom

and they don't change throughout
the mushroom's life cycle.

The spore prints reveal

that mushrooms are more varied
and complex than they might appear.

Their world is mysterious
and little known,

yet they have the power to affect
our lives in unexpected ways.

One of the most striking
displays of that power

takes us to the most unlikely place.

This is Mark Gilchrist,
a consultant pharmacist

at St Mary's Hospital, London.

He spends much of his day
administering and prescribing

the most widely-used type
of drug on the planet -

antibiotics.

Antibiotics are
tremendously important

in our fight against infection.

Up to about 30% of patients
within a hospital setting

can be on antibiotics
at any one time

and that's used to treat
things like pneumonias

to simple skin and
soft tissue infections

and prevent surgical site
infections post operatively.

The invention of antibiotics
has been a game changer

for medicine and mankind.

And we owe it all to fungi.

In 1928, scientist
Alexander Fleming

was carrying out
research at St Mary's.

He was studying the
staphylococcus bacterium,

and left some samples on his desk,
before heading off on holiday,

expecting them to grow and
develop while he was away.

When Fleming returned from his
holiday to resume his research

on bacteria here in this lab,

he noticed something extraordinary.

His bacteria samples were dead.

They had been completely
destroyed by fungi.

Intrigued by why this had happened,

Fleming examined
his samples further.

He realised that a fungus spore,
possibly from a lab below,

must have landed on
the gel plate and germinated.

The spore had rapidly started
to feed on the contents of the dish,

starving and ultimately
killing the bacteria.

The significance
wasn't lost on Fleming.

This could be a new way
to fight bacterial infection

inside the human body.

His discovery led to the creation
of the world's first antibiotic -

penicillin.

And it only happened thanks to
some tiny spores from a fungus,

carried on the breeze.

But to understand how those spores
came to be there at all,

we need to delve deeper
into the secret world of fungi,

right back to the start
of their life cycle,

to the moment a new fungus begins.

I've come to Scotland

to see something I've always
wanted to see but never have,

although I've rehearsed it
many times in my mind's eye.

This is one of the largest
mushroom farms in the UK,

and inside each of
these polytunnels,

there's a spectacular
natural phenomenon taking place -

the birth of fungi.

It's a magical process,
normally invisible,

but tonight I'm going to see it
clearly for the first time.

Well, to a mushroom person,
of course,

this is like being in heaven,

and everywhere you look,
it's extraordinary -

this laser torch picks out
little white specks.

They're so numerous.
This is like shining a beam

up into the Milky Way.

Billions upon billions of spores
in the air all around us,

and they're ubiquitous, so
they're going up to the ceiling

they're going out the door,

they're doubtless going into
my lungs.

If you want a graphic demonstration
of how prolific mushrooms are,

here it is.

So this is how most
fungi begin life.

The mushroom spews out many
millions of spores every hour,

for as long as it remains
above the ground...

..each of them carrying the
potential to be a new fungus.

It's mesmerising to watch,

but I want to know exactly
what's going on here

and to do that,
I'll need more than a laser light.

Back in the mushroom lab,

Patrick can reveal the hidden
mechanisms of mushroom birth.

A mushroom, also known
as a fruiting body,

really is just the reproductive
structure of a fungus

and its sole purpose
is to produce spores.

So to look at these in more detail,

what I'm going to do is take
a very thin section

through this mushroom cap

and put it onto a microscope slide.

There we go... Ah!

That's the business, isn't it?

Yeah, so the large cylindrical
kind of clear part of the cell

is the basidium and those little
spiky bits protruding from it

are called the sterigmata and
they hold the spores in place.

Now, eventually, when those
spores are fully ripened,

they'll drop off into that
air space between the gills,

and fall down from the mushroom.

That whole structure,
including the spores,

is about the width of a human hair,
and, remember, these gills

are packed with them. They're
completely lined with a layer

of these basidia continually
producing spores.

It's a production line.

It's an extraordinary thought,
isn't it? This tiny object,

just a few thousandths
of a millimetre long,

contains the potentiality
for a new mushroom colony.

Exactly.

This constant production line,
forming and releasing spores,

is exactly what I saw so vividly
in action at the mushroom farm.

But that's just one way mushrooms
can spread their spores.

Others do it in
a completely different way.

This is an orange peel fungus,

and it's part of a large group

that fire their spores vertically,
with explosive results,

as we can see here when the action
is slowed down 600 times.

Oh, look at that!

They're like geysers erupting.

The spores are incredibly prolific.
Throughout the course of a day,

each fungus might be capable
of producing over a million spores

and over the lifetime
of that fungus,

we're into tens to
hundreds of millions.

Well, that's extraordinary footage.
I've never, ever seen anything

so graphically displaying the way
fungi get rid of their spores.

It's a truly impressive fungus.

These fungi can reload and
fire time and time again,

often for many days on end.

And how that works

was a brilliant discovery made
by someone you wouldn't expect.

Beatrix Potter is famous for penning
The Tale Of Peter Rabbit,

but what's less well known,

is that she was one of the leading
mushroom biologists of her time.

Both Potter and pioneering
biologist Arthur Buller

spent much of their lives
trying to find out

how some mushrooms
release their spores.

They discovered that
a tiny drop of fluid,

now known as Buller's drop,
forms at the base of every spore.

As the spore ripens
and begins to detach,

the Buller's drop fuses
with a second tiny water droplet

that forms at the side of the spore.

Like two raindrops joining
together on a windowpane,

this fusion causes
a rapid shift in mass

that dislodges the spore
in such a spectacular fashion.

This microscopic process
all takes place

in a few millionths of a second

and is key to how
many fungi reproduce.

But of them all, there's
one particular species

that's a record breaker.

You may think that the fastest
organism on the planet

is a cheetah or maybe
a peregrine falcon,

but you'd be wrong.

Allowing for scale, the speediest
organism on the planet

is actually a tiny fungus.

It grows on top of cowpats.

It's called Pilobolus crystallinus,
or the "Hat Thrower" fungus,

and no other species
demonstrates better

the importance of the spore
release mechanism.

This little fungus feeds
on the dung of herbivores,

but when the supply of nutrients
from one pile has been exhausted,

it needs to move on,

and to do that, it has
to get out of the dung

and onto new blades of grass.

That's the equivalent of you or I

trying to throw a tennis ball
over the Eiffel Tower.

But, then, you or I can't do this.

BANG

MUSIC: "Zorba's Dance"
by Mikis Theodorakis

Using water drop acceleration,
these spore capsules,

seen as little black hats,
can be fired at a speed

of up to 40mph in just
two millionths of a second,

pulling an astonishing
20,000 Gs in the process.

BANG

The little "Hat Thrower" fungus
is a wonderful example

of the sophistication
of fungus evolution.

It throws its spore body more than
a thousand times its own length

into clear grass, away from cowpats,

so that the cows will come along,
graze the grass,

incorporate the spores and
so propagate another generation.

The "Hat Thrower" shows
just how ingenious fungi are

when it comes to reproduction.

They will go to extraordinary
lengths to ensure their own future.

It's the key to why fungi have
become such a dominant life form

with such vast numbers
of species all over the planet.

And it's certainly a talent to which
humankind owes a great deal.

But as impressive as
spore dispersal might be,

it's just the beginning
of the fungus's life story.

It's the next stage that
truly reveals why they are

so vital to all life on Earth.

So far we've just been looking
at the fruit body of the mushroom.

Indeed, I suppose to most people
they think that IS the mushroom.

But it's only part of the story.

To discover how mushrooms relate

to so many other
organisms on our planet,

we have to go further,
we have to go underground.

You'd be forgiven for
thinking that what we see

above the ground is the
main part of the fungus...

..but, in fact, the vast majority of
the organism is hidden underground.

It's a huge web of tiny threads,
spreading out in search of food.

And the only way many fungi
can get what they need,

is by attaching themselves
to other organisms,

and engaging in a two-way
exchange of nutrients.

It's a process that results
in one of the most complex,

yet crucial relationships
in the natural world.

To discover how this works,

I'm meeting Kew Gardens
mycologist Bryn Dentinger.

Anywhere from 70% to 90%
of all plants on Earth

will form a very special
intimate relationship with fungi

and the fungi will attach
themselves to the plant roots,

either directly
penetrating the roots

or sometimes they will form
sheaths on the outside

that will envelop the root
like a kind of glove.

This is where the nutrient
exchange takes place

between the fungus and the root.

This nutrient exchange
works both ways.

The fungus feeds on sugars from
the plant that it needs to grow

and in return gives back
water and minerals

that the planet is unable
to absorb enough of itself.

I'm going to lift up
this pine seedling here

and you can see, where I'm pointing
with my pinkie, that white fuzz.

Oh, yeah, OK.

Those are the fungal filaments

and it is completely covering the
roots of this pine tree right here.

And it extends over a
much larger surface area

than the roots can possibly cover,

and this gives them access
to all kinds of nutrients

and water, even, from the soil,

so they can extract nitrogen
and phosphorous, in particular,

from the soil,

and provide those to the plant,

which the plant will
then exchange for sugars

that it produces through
photosynthesis.

And the two together
make for a better plant?

A better plant and a better fungus,
healthier soil.

So it's a win-win
situation for both?

It's a win-win situation
for both partners

and, in fact, for the entire world.

'We're going to look for evidence
of this vital relationship,

'in the wild.'

Well, we can't see them,

but, all around us there are
these unseen fungal partners.

They're invisible to us when we
just take a nice stroll along a path,

but they're all around us.

Shall we have a go?
Let's do it.

I think I've got some.

Well, I mean, you don't
have to search for it.

You can see the white tips here.
It's very obvious, yeah.

But every one of these tiny
little, side-branching roots

is covered in fungus.

There's a fascinating
and fundamental relationship

between fungi and land plants,

not just here in Kew and every park
in Britain, but in every field.

Without this relationship,
plants couldn't thrive.

It's impossible to
overstate its importance.

So how exactly does this
hidden process happen?

To find out, Patrick has
been capturing it in action,

starting from the moment
a spore hits the ground.

The primary mission of
a fungal spore is to feed

and find food resources.

Now, under the right conditions, the
spore starts to germinate and grow.

That's what we can see here.
We've placed some spores

into a drop of water and as you
can see, they're starting to swell.

There's a little bit of movement
starting to go on inside.

Oh, yeah. And already you can
see this little bud emerging,

and that little bud is the
beginnings of a fungal hypha.

So, what is a hypha?

The hypha is the feeding part
of a fungus, the feeding tube,

and the hypha goes in
search of water and food

and will continue
growing and branching

until it eventually establishes
a colony, a fungal colony.

Does it grow very fast?

Once a hypha finds its food source,
it can develop very quickly

and form what we call a mycelium.

A mycelium is the scientific name
for the fungus's feeding network.

Here magnified 500 times,

we can see one starting to form as
many hyphae begin to web together.

Essentially, it is
a fungus's root system,

a complex series of feeding tubes.

It's not unlike a microscopic
human digestive system,

processing food that
allows it to grow.

Within these tubes are the nutrients
that are a fungus's entire future.

And you can see
the network forming now.

Yeah, and this is in
the centre of the colony.

You have this branched network
that keeps on feeding nutrients

through the colony and sharing
its water and resources.

And that's only half
a millimetre square?

Roughly half a millimetre
is the sort of field of view

that we're looking at here

and it's very much
like a road network -

we've got these
kind of main motorways,

we've got lots of little
side routes in there

and we've got flow of nutrients,
water and it's very dynamic.

For example, if I was to break
one of these tracks,

the fungus would very quickly
adapt and form new connections.

And form new connections
and new routes. Mmm.

It's extraordinary
how bustling it is.

Of course I can now see what
we saw with Bryn Dentinger -

how efficient these hyphae
are at gathering nutrients

and moving through the soil.

Absolutely, and even in the
most dry soil environments,

fungi are able to draw up
the moisture from the soil

and transfer it into the plants
through this co-operation.

It is extraordinary,
extraordinary footage.

Although the mycelium is almost
entirely invisible to us,

it makes up the vast
majority of the organism.

And its size can be
truly breathtaking.

So big, in fact, it can
often extend for miles.

The biggest organism in the
world is not the blue whale,

but a mycelium that spreads
across an incredible 2,384 acres

in Oregon's Blue Mountains.

It's called Armillaria mellea,
or the honey fungus,

and this example is thought
to be over 2,000 years old.

It's a mind-boggling example
of how far a mycelium can grow.

But it also reveals just how
destructive a feeding fungus can be.

These are clumps of honey fungus.

It's the same fungus
that spread inexorably

through the forests of Oregon

and it demonstrates a very
different, some would say sinister,

relationship between
mycelium and trees.

Unlike the balanced
nutrient exchange

that we see between most
fungi and their plant partners,

honey fungus takes much more
from its host than it gives.

It consumes all the sugars it needs,

but crucially doesn't give
back enough water and nutrients

to help the tree grow properly.

As a result, the greedy mycelium
of this fungus thrives,

while the tree slowly weakens.

Honey fungus is a slow killer.

It advances from tree to tree
on hidden threads.

As our tree population ages
and some sickens,

the rise of honey fungus
is inexorable.

But it's not the biggest threat
to our plants and trees.

There's another species of fungus
whose hunger is even more deadly.

I've come to Norfolk to find
evidence of a fungus

that's very difficult to see,

but whose eating habits

are threatening to wipe out
one of Britain's oldest trees.

Just a few years ago, a new
killer arrived in Britain -

ash dieback disease,

or Chalara fraxinea,
to give it its scientific name.

And no fungus better demonstrates

the greed of mycelium
for nourishment...

..and if it has its way, maybe,

magnificent forest trees
like this ash

may yet become just
a part of history.

David Bole knows all too well

just how destructive
this fungus has become.

And there's quite a lot of
dieback in here, isn't there?

Yeah.

This is one of the first woods
where we discovered it.

What we're finding now is
that there's over 500 cases

in the wider environment and
as we do more in-depth surveys,

more and more cases
are coming to the fore.

Take me through the symptoms.

Well, the first thing to look for
is this, the black leaves,

which we've got here

and we've got a really good example
on this little, young tree here.

The leaves have died
but they're black.

They really don't look healthy and
they're hanging onto the tree.

I notice they die from the top too,

so they're dead up here
but still green down here.

Yes, you know, it's called
dieback and that's a good way

to think of it - we have
the tree slowly dying back.

Other symptoms are these
diamond-shaped lesions.

The fungus lands on the leaves,
the mycelia come in,

and works its way up and down
the cells of the tree

and forms these very particular
diamond-shaped lesions.

This process is rather
eerily called necrotrophy,

which means eating the dead.

The feeding hyphae of ash dieback

attach themselves
to their tree hosts

in the same way as other fungi,

but they obtain their sugars
without providing any nutrients

or water in return.

It's all one-way traffic

and has a fatal outcome.

OK.

OK, so let's just have a look inside.

Oh, yeah. You can
see discolouration.

It's absolutely patent.

So the disease has entered here
and this is the fungal mycelia,

which are starting to work
its way inside the tree.

The mycelia get inside all the cells

that transport the water up
and down the tree

and stop the water transport

and so the tree effectively
dies of thirst, if you like.

It's a sad end to one of our most
beautiful and elegant forest trees.

It really, really is, yes.

I mean, we'll probably
lose a generation of ash

but let's hope we see
that coming back.

Ash dieback demonstrates just what
happens when the delicate balance

between plant and fungus
gets out of kilter...

..and that's what
allows this disease

to spread so far and so fast.

It also shows just what a voracious
eater fungal mycelium can be.

But though this
unstoppable appetite

can be deadly in the natural world,

some scientists are looking
to turn it to our advantage.

This is Eben Bayer,
an entrepreneur based in New York.

He noticed something
intriguing that happens

when some mycelium spreads
out in search of food.

First time I saw mycelium
in action was holding

clumps of woodchips
together on my family farm

and rather than falling apart,

they'd be held together
by these white fibre strands.

One night, sitting at home
on my futon in my apartment,

I got this crazy idea about,
"Hey, mycelium seems to grow,

"and glue the forest floor together.

"Maybe we can use it as a glue."

Eben saw huge potential in this
binding property of mycelium.

He used it to create
a new kind of packaging,

one that he believes
could, ultimately,

become an eco-friendly
alternative to some plastics.

Just in packaging alone,
there's like billions of dollars

of Styrofoam used every year,

somewhere between $3.5
and $5 billion of styrene,

and the biggest issue with
plastics is at their end of life

and with our material,
you get something that,

at the end of its useful life,
can be composted, right.

Your packaging becomes a nutrient for
your neighbourhood, not a pollutant.

To make his new material,
Eben mimics what happens in nature.

He takes some ground corn stalks
and seeds them with fungus spores.

The spores germinate, and
begin to feed on the stalks,

breaking down and digesting them,
so the mycelium can start to grow.

The mixture is then placed
inside a mould and left

for the mycelium to perform
its biological magic.

So, they'll sit on a rack like this
for anywhere from 24 to 72 hours.

It doesn't look like
anything's happening,

but the mycelium
is already going to work,

growing and extending out
from every one of these particles

and building a strong, tough network.

And within 24 hours, this
part will look a little white

and that's the mycelium
gluing everything together.

So this is a finished corner block.

It's been grown in our production
process, it's been moulded

and all of this came from that
loosie-goosie agricultural by-product

you saw at the beginning.

Pretty incredible, huh?

What we've done with mycelium here,

which is basically leveraging
a living organism

to create really great technology,

is where the excitement is,
that's where the innovation is

and that's where the solutions are
going to be for the next 100 years.

So the mushroom mycelium could
help us tackle the global problem

of plastic waste.

But Eben's work also demonstrates
another important trait

of the feeding mycelium.

While some fungi feed
on living organisms,

others only eat those that are dead.

These fungi are able to break
down and digest organic waste

and in doing so, recycle it.

This process is called saprotrophy

and it's absolutely vital
in the natural world.

In this damp wood,
the litter of leaves,

indeed, every twig, is being
consumed by mycelium,

that breaks down the
cellulose and other compounds.

Even...

Even wood can be digested by fungi.

The hard lining that gives
the wood its strength

can be consumed and the wood reduced
to little more than rubble.

Were it not for the relentless
activity of mycelium, in fact,

the whole planet would be covered
with a mass of undigested scrub.

It's hard to overstate the
importance of saprotrophic fungi.

They have successfully recycled
the world's natural waste

for hundreds of millions of years,

making entire ecosystems habitable
for animal and plant life.

So how do they achieve
this crucial trick?

So, Patrick, let's talk rot.

Few people realise
just how important

those saprotropes
fungi are in nature.

How does it work?

Well, fungi are really
quite invasive.

The fungi have this mycelium, which
penetrates deep into the waste

and unlike us, where our
stomachs are internal,

the fungi secrete their digestive
juices out into the environment

and start breaking down
the complex molecules,

things like cellulose,
into more simple forms.

This is via a myriad of
those little hyphal threads.

That's right.

And to demonstrate just how
effective saprotrophic fungi are

at breaking down organic matter,

I've put several days
of kitchen waste into this beaker

and I've filmed it over two weeks

to see just how quickly
it goes down, it rots down.

SQUELCHING

So there it is,
just sort of sinking down.

Yeah. Lots of juice exuding
from the vegetables.

So the invisible threads of the
mycelium are getting in there,

breaking vegetables and
the other organic waste,

into something they can use.

The other important thing
to note here

is that when all these vegetables
did go into the beaker,

they already had spores on them,
so they were already pre-seeded

with the spores.
Because spores are everywhere.

Exactly, when you bring the
food back from the supermarket,

it'll already have a coating of a
whole cocktail of different spores

and as soon as those fungi are
in a slightly warm environment,

it becomes quite a
feeding frenzy, if you like.

So, Richard, I'm going to show
you the results of the one

that I prepared two weeks ago.

Well, it couldn't be much
clearer than that.

Yeah. Look how far it's gone down.
This was the start point and...

At least a third.

..it's gone down about a third and
I'd expect, within another two weeks,

to be almost to the bottom.

If this process wasn't happening

we would just be surrounded
by organic waste matter.

Heaps of vegetables. Exactly.

What it does show
is just what makes the fungi

such efficient seekers after...
scavengers after nutrition.

Yep.

Extraordinary.

The brilliant way the mycelium
of a saprotrophic fungus

uses digestive juices just like
humans to break down waste

makes it a recycling machine
like no other.

And it doesn't stop there.

For as saprotrophic fungi
recycle organic matter,

they're performing a key role
in creating healthy soil,

soil that can, in turn,
sustain new plant life

and that's also a home for
a host of other life forms,

tiny micro-organisms
that live within it.

And for some fungi,

the arrival of these new guests is
just another feeding opportunity.

These oyster mushrooms,
or Pleurotus,

have mycelium that breaks down
the wood in rotting logs.

They're quite
efficient at doing this,

but they have a shortage of
one essential element, nitrogen

and to make good this deficiency,

they've evolved
a very special trick.

From the end of some of its hyphae,

the oyster mushroom
emits tiny lassos

that secrete a powerful toxin.

And it does this for one reason...

..nematode worms.

These tiny organisms
live within the logs

and happen to be rich
in the nitrogen

that the hungry mushroom needs.

The oyster mushroom lures the
nematodes towards their tiny lassos

before enveloping them.

Once trapped, it's curtains
for the little worm,

and dinner for the mushroom

as it gets the nitrogen-rich
fluid it needs.

The oyster mushroom's rather
gruesome feeding trick

demonstrates yet again just how
sophisticated a fungus can be

when it comes to getting
the food it needs.

It's a talent that, once again,
we humans are looking to harness.

Over in Washington State,
mycologist Paul Stamets

has turned to our hungry friend
the oyster mushroom,

in the hope he can use it
on a truly grand scale -

to tackle some of our most
pressing environmental problems,

such as chemical pollution.

One of my great realisations in life
is that habitats have immune systems

just like we do,

but mushrooms are the
bridges between the two.

These things unravel and break down
large molecules into smaller ones

that are very useful for other
members in the ecological community.

The course of that decomposition,
has many different properties

that we can use for
breaking down toxic waste.

That looks good.

Paul discovered that
mushroom mycelium

can break down the hydrocarbons
present in much chemical waste.

It's a process he
calls bioremediation.

The mushroom is greedily
eating the pollutants away.

It looks convincing in the lab,

but does it work in practice?

Paul's theory was recently put
to the test on an industrial level

when a heavily-polluted
petrochemical site

was seeded with oyster
mushroom mycelium.

The work was carried out
by environmental engineer

Howard Sprouse.

Yeah, bring her down
a little for me.

After just two days, the team
found that their polluted pile

had been transformed by
the mushroom mycelium

and was now teeming with new life.

Well, this is interesting. We've
got lots of worms in here now.

That's a good sign.

If it drops any more, we're going to
be able to use this soil anywhere.

The contaminate has gone...

..the decomposition process
that the fungi have started

is continued by other
soil microorganisms

and you end up with soil that's
richer than it was when you started.

Paul's study shows that
oyster mushroom mycelium

can not only digest chemical waste -

it also manages to create
an entirely new ecosystem

in the process.

At a time when the Earth is
suffering from toxin exposure,

erosion of habitats, overpopulation,

deforestation,
loss of soil integrity...

..mushrooms present themselves
with unique properties

that can address all those
problems with a single group,

and that's what I find so exciting -

that the solutions are
literally underfoot.

Paul's work shows just how great

the potential of fungus
mycelium might be.

Its hidden underground threads
act upon their natural environment

in truly remarkable ways we are
only now beginning to realise.

But as vital as it could be to us,

the mycelium's feeding quest
has one simple goal...

..to produce its fruiting body...

..bringing the organism to
the end of its life cycle.

We've seen how mycelium can
form complex feeding webs

and how the mycelium underpins
so many of Earth's ecosystems...

..yet that mycelium itself
has only one purpose...

..to fulfil its own life cycle and
to lead once again to the mushroom.

For the fungus, this final stage
simply means reproduction

and the dispersal
of billions of spores.

'But for another species,

'it's just the beginning of
its relationship with fungi.'

Nice find.

'And that species is us.'

Ah.

The sulphur tuft.

Very abundant.

Very inedible.

'Its mythical status
in folklore and magic

'has made the mushroom an object
of both fascination and fear.'

Well, now, this is a troublemaker.

'And sometimes that fear
can be for good reason.'

Poison pie is, as its name suggests,
not a good thing to eat.

Go out into any woodland

and you're likely to encounter
a wide range of poisonous fungi

that you certainly would not
want on your dinner plate.

People get a big nervous
about this one...

the Sickener.

Well, the name tells you everything.
You don't want to eat it.

The notion that fungi
can be poisonous

is what frightens us
most about them.

This is the most poisonous
mushroom known to man.

It's the death cap.

People have eaten it, apparently
in mistake for a field mushroom.

I can't think how.

But they'd have cause to regret it,
because half a cap of one of these

is enough to kill a grown man,

and slowly,

and painfully.

I've been a field mycologist
for many years

and know to avoid dangerous
mushrooms like the death cap,

but their toxicity does raise
an interesting question -

what is it that gives
mushrooms the power to kill?

To explore this, I've come back
to the lab once final time.

Every fungus will have a cocktail
of different chemicals within it,

and depending on what type it is,
there's various different types

of poisonous chemicals which
are present in these mushrooms.

Possibly one of the worst ones is
something like the destroying angel.

Or the death cap, which
is its close relative.

Or the death cap, and those have
a substance called amatoxins,

which are deadly toxic.

You'd only have to eat one or two
of these to be completely poisoned.

You'll end up with liver failure,
kidney failure and death

and it's a really
quite nasty way to go.

So we know that mushrooms are
toxic, but why are they toxic?

Well, there's a theory that
mushrooms evolved to become toxic

in order to discourage
predators from eating them,

but I'm not sure
that's exactly the case,

so I've set up a little test
with a selection of mushrooms

and we've brought in a guest
to do the test for us.

Patrick has offered a selection
of five mushrooms to a hungry slug,

one of which is poisonous to humans.

But which will it prefer?

After a look around and having
a nibble of one or two,

he seems to have settled on this one.

Oh, the sulphur tuft, which is
famously bitter and poisonous.

Yeah, it doesn't seem
to bother the slug

and, in fact, he seems to be having
a tasty meal on the gills, there.

So what we've seen is certainly
not in support of the idea

that fungi are kind of protecting
themselves from being eaten

until mature. In fact, you
could argue that that mushroom

actually wants to be eaten,

so what's it all about?

I think, really, the bigger picture

is the diversity within
the fungal kingdom,

in that the fungi produce
thousands of different chemicals

and it just so happens that
some of those are toxic to us,

whereas they might not be toxic to
something like a slug or an insect.

In fact, it may be a very important
food source for those animals.

So you've just got a huge spectrum
of different types of chemicals.

And we're only just
beginning to explore

the implications of some of these.
Absolutely.

We don't yet fully
understand why some fungi

have such a potent effect on us.

More research is needed.

But, already,
we're beginning to exploit

some of their seemingly sinister
behaviours for our own benefit.

Can I introduce you to cordyceps?

These are dried specimens
of a very famous fungus,

famous in Chinese medicine
for curing all manner of ills.

It's a curious fungus with
a strange, parasitic lifestyle.

Unlike most fungi,
it doesn't feed on dead matter

but instead seeks out
a very different host.

Like something out
of science fiction,

this fungus grows inside insects,

slowly killing them until the
fruiting body is ready to emerge.

But despite its rather,
alien life habits,

the chemicals concealed
inside the cordyceps

may yet prove crucial to
a major medical breakthrough.

Doctor Cornelia De Moor from
the University of Nottingham

is using this little mushroom
in a cutting-edge treatment

for one of our most
feared diseases -

cancer.

So in cordyceps there are very
high levels of this cordycepin.

And cordycepin is a compound

that is actually only
very slightly changed

from a very common compound that you
find in all cells called adenosine.

It's only one oxygen difference.

But for some reason, only
cordyceps fungi make cordycepin

while all organisms make adenosine.

This unique compound produced by
cordyceps has long been of interest

to alternative medicine in the
treatment of cancerous tumours.

But how it worked was never clear
and Cornelia was keen to find out.

What surprised us immensely
the first time we treated cells

with cordycepin is when we put
cordycepin on cells like that,

they changed shape
into cells like that

in which the little grains are gone
and the cells start to shrink.

So when we saw this,

we knew there was something quite
fundamental happening to the cells

and that then led
to our later discoveries

on the affects of cordycepin.

Cornelia knew that with any cancer,

in order for the individual
cells to multiply and grow,

they must join themselves together

using tiny stems
called poly-A tails.

And it's here that she has
discovered that cordycepin

plays a crucial role.

So we've been doing some work
on breast cancer cells,

which we've been treating
with cordycepin,

and what we're seeing is that
the cordycepin appears to stop

the making of the long poly-A tail.

So it might not kill the cell

but the most important thing - it
stops the growth of the cancer cell,

by cutting off the machinery that
is necessary for cell growth.

It is a completely new
mechanism for a cancer drug,

so all other cancer drugs work on
completely different principles,

not on inhibiting
this polyadenylation,

so it could be the first
of a new class of drugs,

not only for cancer, but also
for inflammatory diseases.

Medical breakthroughs,
from Fleming's penicillin

to cutting edge cancer research,
reveal an extraordinary truth.

The cells of fungi have the ability

to interact with our own cells
on a profound level...

..to alter them in ways that affect
our health, even our survival.

And this is a powerful clue

to the true relationship
between fungi and us.

Time and again, we seem to discover
deep biological connections

between ourselves and the fungi.

But what could we have
in common with a mushroom?

To find out the answer,
we have to delve deep

into our own evolutionary history.

As we've seen, fungi are
neither plant nor animal.

Early in the story of life on Earth,

they established themselves as
a kingdom in their own right.

But it's the moment when this
happened that is truly significant.

At the point when plants
and animals diverged,

the fungi were still part
of that animal branch.

It was not until about
ten million years later

that they began their
own evolutionary journey

as a distinct kingdom.

This explains why they have retained
a number of key biological traits

that make them much more animal
than plant, much more like us.

Traits we've seen
time and time again,

as we've explored their
fascinating life cycle...

..from the explosive way that
they release their spores...

..to the way they feed and digest
other organisms, much as we do.

At every stage of their life,

fungi reveal just how
much like us they are.

It's a powerful connection,
that explains why we work

so well together.

So we are all much more mushroom
than you could ever imagine.

And because of this close affinity,
sometimes the fungi work with us,

and even sometimes against us...

..and that is the true
magic of mushrooms.