Name: 6 環境を救う微生物 (6 Microbes Saving the Environment)
Uploaded: 2021-01-14T10:29:53.000Z
Duration: 13 min 57 s
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Ever since humans found out germs were a thing,

The idea that death can be doled out by stuff we can't even see

So we invented antibacterial soap and antibiotics and antifungals,

and we went a little bit overboard in the end with the anti-everythings.

And as a result, we've often ignored the existence of good microbes.

With the exception of the ones that give us cheese and yogurt

But good microbes do a lot more than make yogurt yogurty

They also help us digest food and fight illness.

And the more we've learned about them, the more we've realized

that they have the capacity to do really big things.

Like help us protect endangered species and maybe even undo

some of the big mistakes we have made as humans.

So here are six examples of microbes helping to save the world.

The first, koalas. They are notoriously picky eaters.

Although they've occasionally been seen eating leaves

from other trees, for the most part, they eat eucalyptus leaves.

And they're even picky about which species of eucalyptus they eat.

So, these things are cute, but they're also, like,

Thankfully, that's not too much of an issue for them.

Australia is full of eucalyptus trees, and there isn't a lot of competition

for it since the plant's leaves are toxic.

Koalas can only digest it thanks to a special type of gut bacteria —

one they acquire as babies when they eat what's called pap.

That's a special kind of microbe-rich poop

So overall, this lifestyle works for them. Or it did.

In the next sixty years, climate change is expected to

reduce the distribution of most Australian eucalyptus species

Urbanization and habitat destruction are also a threat,

and that was before the devastating Australian wildfires

(which started in 2019) added even more pressure.

In response to this, you would think koalas might switch

But they don't always do that — in part, because

their digestive systems are just so specialized

In 2019, scientists successfully transplanted the gut bacteria

from koalas who ate one type of eucalyptus, called messmate,

into the guts of those who were used to eating another type,

Specifically, they gave the manna gum koalas capsules

that contained microbes extracted from the poop of messmate koalas.

Which is like, you know, slightly less gross than eating actual poop.

The scientists hoped that the unique microbes from the messmate koalas

would help the other group's bodies digest the new food.

And at the end of the experiment, the manna gum eaters

were eating more messmate. So… success!

To be fair, though, the researchers weren't totally sure

if this happened because of the increase in gut bacteria,

or if the gut bacteria were increasing because the koalas were eating

But it's intriguing to think that poop and the bacteria it contains

To the delight of poop joke enthusiasts everywhere.

Next, malaria is one of humanity's most deadly foes.

But we aren't the only species that gets it.

Bats, reptiles, birds — there are a lot of animals on malaria's hit list,

although not all of them are affected by it the way we are.

Although it can shorten birds' lives, it usually doesn't kill them.

In some isolated places, though, avian malaria can be deadly. Like in Hawai'i.

Until humans came along, birds in Hawai'i had no exposure

to the malaria parasite — because there were no mosquitos

According to a local legend, that only happened when a bunch of sailors

dumped a barrel full of water and mosquito larvae

When the mosquitos arrived, so did the avian malaria parasite.

And after native Hawaiian birds were introduced to it,

Thankfully, there might be a way to control this disease in Hawai'i

And it's not insecticide — because although that's been the standard for years,

mosquitos have an annoying habit of becoming resistant to it.

Instead, scientists are testing a new weapon: a bacteria called Wolbachia,

which naturally infects a lot of other insects,

But in a 2009 experiment, scientists took some Wolbachia

and managed to infect a group of Aedes aegypti mosquitoes with it.

Those are mosquitos that carry a whole bunch of diseases,

Then, they had those mosquitos drink the blood of chickens

infected with the avian malaria parasite.

And normally, this would result in the insects becoming malaria carriers.

But in this case, the mosquitos actually appeared to have

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6 環境を救う微生物 (6 Microbes Saving the Environment)

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