The mysterious microbes living deep inside the earth -- and how they could help humanity | K. Lloyd

譯者: Dai-Yun Wu 審譯者: Helen Chang

It may seem like we're all standing on solid earth right now,

我們看似腳踏在堅實的地表上，

but we're not.

但其實並非如此。

The rocks and the dirt underneath us are crisscrossed by tiny little fractures

地底下的岩石與塵埃 藉著微小的碎裂物

與空間相互交錯著。

and empty spaces.

And these empty spaces are filled with astronomical quantities of microbes,

這些空間被數不清的微生物填滿，

such as these ones.

如同這些。

The deepest that we found microbes so far into the earth

我們目前在地球上發現微生物

is five kilometers down.

最深達距地面五公里。

So like, if you pointed yourself at the ground

就好像，若你把自己固定在地面上，

and took off running into the ground,

然後開始往地底跑，

you could run an entire 5K race and microbes would line your whole path.

微生物可以排一整路，全程五公里。

So you may not have ever thought about these microbes

你可能從沒想到過這些

that are deep inside earth's crust,

在地殼深處的微生物，

but you probably thought about the microbes living in our guts.

但你可能會想到 住在我們消化道中的微生物。

If you add up the gut microbiomes

如果你將地球上所有人與動物

of all the people and all the animals on the planet,

體內的微生物全部相加，

collectively, this weighs about 100,000 tons.

總共可重達十萬噸。

This is a huge biome that we carry in our bellies every single day.

我們的肚子每天都扛著 如此巨大的生物群。

We should all be proud.

我們應該都要感到自豪。

(Laughter)

（笑聲）

But it pales in comparison to the number of microbes

但跟覆蓋在地表的微生物數量相比，

that are covering the entire surface of the earth,

可就相形見絀了。

like in our soils, our rivers and our oceans.

例如在土壤中、河流中， 以及海洋中的微生物。

Collectively, these weigh about two billion tons.

這些地方的微生物量 總共約 20 億噸。

But it turns out that the majority of microbes on earth

然而令人意外的是， 大多數在地球上的微生物

aren't even in oceans or our guts or sewage treatment plants.

並不存在於海洋、 消化系統或污水處理廠中，

Most of them are actually inside the earth's crust.

它們大多存在於地殼中。

So collectively, these weigh 40 billion tons.

這些總重達 400 億噸。

This is one of the biggest biomes on the planet,

這是地球上最大的生物群之一，

and we didn't even know it existed until a few decades ago.

而我們直到幾十年前才知道它的存在。

So the possibilities for what life is like down there,

因此在地表下的生活如何，

or what it might do for humans,

或它會如何影響人類，

are limitless.

是無限的。

This is a map showing a red dot

這是個地圖，地圖上的紅點代表

for every place where we've gotten pretty good deep subsurface samples

每一個我們藉現代微生物研究法

with modern microbiological methods,

已取得不錯的地底樣本的地方，

and you may be impressed

你可能會欽佩我們

that we're getting a pretty good global coverage,

受到全球報導關注，

but actually, if you remember that these are the only places

但事實上，如果你記得這些點是

我們唯一能找到樣本的地方， 這看起來就會有點糟糕。

that we have samples from, it looks a little worse.

如果我們現在在一個外星船上，

If we were all in an alien spaceship,

trying to reconstruct a map of the globe from only these samples,

想靠這些樣本重建地球的地圖，

we'd never be able to do it.

是辦不到的。

So people sometimes say to me,

因此有時候會有人跟我說：

"Yeah, there's a lot of microbes in the subsurface, but ...

「對，地表下有很多微生物，可是...

aren't they just kind of dormant?"

它們不都在休眠狀態嗎？」

This is a good point.

這是一個很好的論點。

Relative to a ficus plant or the measles or my kid's guinea pigs,

相對於榕屬植物、麻疹， 或我的孩子養的天竺鼠，

these microbes probably aren't doing much of anything at all.

這些微生物看似 對我們沒有什麼影響。

We know that they have to be slow, because there's so many of them.

我們知道它們的影響必是緩慢的， 因為它們數量很大。

If they all started dividing at the rate of E. coli,

如果它們他們開始 以大腸桿菌的速率分裂，

then they would double the entire weight of the earth, rocks included,

它們會在一夜之間使地球，

包含岩石的重量加倍。

over a single night.

In fact, many of them probably haven't even undergone a single cell division

事實上，很多微生物 甚至自古埃及時期以來，

尚未經歷任何細胞分裂活動，

since the time of ancient Egypt.

Which is just crazy.

非常不可思議。

Like, how do you wrap your head around things that are so long-lived?

該如何理解這種如此長壽的東西？

But I thought of an analogy that I really love,

但我想到了一個我很愛的比擬，

but it's weird and it's complicated.

但它很怪也很複雜。

So I hope that you can all go there with me.

我希望你們可以跟著我。

Alright, let's try it.

好，我們來試試看。

It's like trying to figure out the life cycle of a tree ...

這就好像你只活一天，

if you only lived for a day.

但你卻想弄清楚 一棵樹的生命週期一樣。

So like if human life span was only a day, and we lived in winter,

所以如果人的壽命只有一天， 而且我們活著的時候是冬天，

then you would go your entire life

那麼你將一輩子

without ever seeing a tree with a leaf on it.

看不到樹上長葉子。

And there would be so many human generations

而一個冬天就會有好幾個

that would pass by within a single winter

人類的世代輪替，

that you may not even have access to a history book

甚至你沒有機會

看到歷史書上寫著：

that says anything other than the fact that trees are always lifeless sticks

樹就是沒有生命也沒有功用的棍子。

that don't do anything.

Of course, this is ridiculous.

當然，這很荒謬。

We know that trees are just waiting for summer

我們知道樹只是在等待夏天，

so they can reactivate.

夏天一到他們就能恢復活動。

But if the human life span

但如果人類的生命週期

were significantly shorter than that of trees,

遠比樹木們來得短，

we might be completely oblivious to this totally mundane fact.

我們可能不會知道 這個平凡無奇的事實。

So when we say that these deep subsurface microbes are just dormant,

所以當我們說這些 地底深層的微生物在休眠，

are we like people who die after a day, trying to figure out how trees work?

我們是不是就如同那些一天就死， 卻想研究樹木生命的人呢？

What if these deep subsurface organisms

會不會這些地底深處的微生物

are just waiting for their version of summer,

只是在等待它們的夏天，

but our lives are too short for us to see it?

而我們的壽命短得 不足以見證這件事呢？

If you take E. coli and seal it up in a test tube,

如果你把大腸桿菌放進密閉的試管中，

with no food or nutrients,

不提供食物或養分，

and leave it there for months to years,

就這樣放好幾個月或好幾年，

most of the cells die off, of course, because they're starving.

當然，大多數的細胞 會因為飢餓而死亡，

But a few of the cells survive.

但有一些細胞存活。

If you take these old surviving cells

若你拿這些舊有生存下來的細胞

and compete them, also under starvation conditions,

與新培養出來 成長快速的大腸桿菌相比，

against a new, fast-growing culture of E. coli,

同樣在飢餓的情境下，

the grizzled old tough guys beat out the squeaky clean upstarts

這些老細胞每一次都戰勝

every single time.

那些新細胞。

So this is evidence there's actually an evolutionary payoff

這就是它們演化如此緩慢

to being extraordinarily slow.

但有成果的證據。

So it's possible

因此可能我們不該

that maybe we should not equate being slow with being unimportant.

將緩慢與不重要劃上等號。

Maybe these out-of-sight, out-of-mind microbes

這些我們看不見、想不到的微生物

could actually be helpful to humanity.

可能對人類有實質幫助。

OK, so as far as we know,

就我們目前所知道的，

there are two ways to do subsurface living.

有兩種在地底下生活的方式：

The first is to wait for food to trickle down from the surface world,

第一種是等待食物從地表上往下滴，

like trying to eat the leftovers of a picnic that happened 1,000 years ago.

就好像試著吃一千年前的 野餐剩餘的碎屑。

Which is a crazy way to live,

這是個很瘋狂的生活方法，

but shockingly seems to work out for a lot of microbes in earth.

但令人吃驚的是，似乎很多地球上的 微生物是這樣生活的。

The other possibility is for a microbe to just say,

另一個可能性是微生物説：

"Nah, I don't need the surface world.

「吶，我不需要地表世界的東西，

I'm good down here."

我在下面活得很好。」

For microbes that go this route,

對於這一類的微生物，

they have to get everything that they need in order to survive

它們必須從地球的內部

收集它們生活所需的一切。

from inside the earth.

Some things are actually easier for them to get.

有些東西反而在地底容易取得，

They're more abundant inside the earth,

這些資源在地球內部充足——

like water or nutrients, like nitrogen and iron and phosphorus,

像水或養分，如氮、鐵和磷——

or places to live.

是宜居之處。

These are things that we literally kill each other to get ahold of

這些東西在地表上

是生物互相殘殺才能取得的。

up at the surface world.

But in the subsurface, the problem is finding enough energy.

但在地底下最大的問題 是尋找足夠的能量。

Up at the surface,

在地表上，

plants can chemically knit together carbon dioxide molecules into yummy sugars

植物可以在陽光的光子 碰到葉子的同時

as fast as the sun's photons hit their leaves.

就能藉由化學反應 將二氧化碳分子轉換成美味的糖。

But in the subsurface, of course, there's no sunlight,

但在地底下沒有陽光，

so this ecosystem has to solve the problem

所以這裡的生態系就必須解決

of who is going to make the food for everybody else.

誰要為大家提供食物的問題。

The subsurface needs something that's like a plant

地底下需要類似植物

但藉著石頭呼吸的東西。

but it breathes rocks.

Luckily, such a thing exists,

幸運的是，這樣的東西確實存在，

and it's called a chemolithoautotroph.

叫作「化能自養生物」。 （chemolithoautotroph）

(Laughter)

（笑聲）

Which is a microbe that uses chemicals -- "chemo,"

也就是使用化學物質——chemo

from rocks -- "litho,"

來源是岩石——lithos

to make food -- "autotroph."

來製造養分——autotroph。

And they can do this with a ton of different elements.

它們可以利用很多種 不同的元素來進行，

They can do this with sulphur, iron, manganese, nitrogen, carbon,

可以使用硫磺、鐵、錳、氮、碳，

some of them can use pure electrons, straight up.

有些還可以使用純電子。

Like, if you cut the end off of an electrical cord,

比方說，你把電線的尾端剪掉，

they could breathe it like a snorkel.

它們可以把它當潛水呼吸管吸。

(Laughter)

（笑聲）

These chemolithoautotrophs

這些化能自養生物

take the energy that they get from these processes

利用從這些步驟取得的能量

and use it to make food, like plants do.

來製造養分，就像植物一樣。

But we know that plants do more than just make food.

但我們知道植物不只製造養分，

They also make a waste product, oxygen,

它們還製造對它無用的 副產品——氧氣，

which we are 100 percent dependent upon.

也就是我們百分之百依賴著的氧氣。

But the waste product that these chemolithoautotrophs make

但這些化能自養生物 所製造出來無用的副產品

is often in the form of minerals,

大多以礦物質的形式存在，

like rust or pyrite, like fool's gold,

像是鏽或硫化礦，像是愚人金，

or carminites, like limestone.

或砷鉛鐵礦，像石灰岩。

So what we have are microbes that are really, really slow, like rocks,

所以這些微生物很緩慢、 很緩慢地，如同石頭一般，

that get their energy from rocks,

從岩石取得能量，

that make as their waste product other rocks.

再將無用的副產品變成其他岩石。

So am I talking about biology, or am I talking about geology?

那我到底是在討論生物學 還是地理學呢？

This stuff really blurs the lines.

這界線實在很模糊。

(Laughter)

（笑聲）

So if I'm going to do this thing,

我如果要做，

and I'm going to be a biologist who studies microbes

就得是生物學家，

研究行為像岩石的微生物，

that kind of act like rocks,

then I should probably start studying geology.

我也應該研讀地理學。

And what's the coolest part of geology?

地理學最酷的部份是什麼？

Volcanoes.

火山。

(Laughter)

（笑聲）

This is looking inside the crater of Poás Volcano in Costa Rica.

這是向哥斯大黎加的波阿斯 （Poás Volcano）火山口往看的樣子。

Many volcanoes on earth arise because an oceanic tectonic plate

許多地球上火山的形成都是因為

海洋板塊衝撞大陸板塊。

crashes into a continental plate.

As this oceanic plate subducts

當這個海洋板塊隱沒，

or gets moved underneath this continental plate,

或被移動到這個大陸板塊下方時，

things like water and carbon dioxide and other materials

水、二氧化碳或其他物質

get squeezed out of it,

就會被擠壓出來，

like ringing a wet washcloth.

就像擰乾濕毛巾一樣。

So in this way, subduction zones are like portals into the deep earth,

如此一來，隱沒帶就像 通往地底深處的門戶，

where materials are exchanged between the surface and the subsurface world.

地表與地底的物質在此交換。

So I was recently invited by some of my colleagues in Costa Rica

我最近受哥斯大黎加同事之邀，

to come and work with them on some of the volcanoes.

去跟他們一起研究火山。

And of course I said yes, because, I mean, Costa Rica is beautiful,

我當然答應了， 因為哥斯大黎加很美，

but also because it sits on top of one of these subduction zones.

也因為這個國家座落於 其中一個隱沒帶之上。

We wanted to ask the very specific question:

我們想問這個特定的具體問題：

Why is it that the carbon dioxide

為什麽從這個深埋的海洋板塊

that comes out of this deeply buried oceanic tectonic plate

釋放出來的二氧化碳

is only coming out of the volcanoes?

只從火山口排放出來呢？

Why don't we see it distributed throughout the entire subduction zone?

為什麼不是一整個隱沒帶 都有排放二氧化碳的蹤跡呢？

Do the microbes have something to do with that?

微生物跟這件事有什麼關聯嗎？

So this is a picture of me inside Poás Volcano,

這是我在波阿斯火山裡面的照片，

along with my colleague Donato Giovannelli.

與我同行的是 同事 Donato Giovannelli。

That lake that we're standing next to is made of pure battery acid.

我們站立處旁邊的湖 完全像是由電池裡的酸所組成。

I know this because we were measuring the pH when this picture was taken.

我會知道是因為我們拍照當時 正在測量其酸鹼值。

And at some point while we were working inside the crater,

在火山口裡工作的某個時刻，

I turned to my Costa Rican colleague Carlos Ramírez and I said,

我轉向我的哥斯大黎加同事 Carlos Ramírez，問他：

"Alright, if this thing starts erupting right now,

「好，如果現在這個東西開始噴發，

what's our exit strategy?"

我們的逃生策略是什麼？」

And he said, "Oh, yeah, great question, it's totally easy.

他回答：「喔， 很好的問題，這非常簡單，

Just turn around and enjoy the view."

就轉過身欣賞風景吧。」

(Laughter)

（笑聲）

"Because it will be your last."

「因為那會是你的最後一眼。」

(Laughter)

（笑聲）

And it may sound like he was being overly dramatic,

他的話聽起來似乎過於戲劇化，

but 54 days after I was standing next to that lake,

但自我們站在那湖邊的 54 天之後，

this happened.

發生了這件事。

Audience: Oh!

觀眾：噢！

Freaking terrifying, right?

超級可怕，對吧？

(Laughs)

（笑）

This was the biggest eruption this volcano had had in 60-some-odd years,

這是這座火山六十餘年來 最大的一次噴發；

and not long after this video ends,

在這影片結束的不久後，

the camera that was taking the video is obliterated

拍攝這支影片的攝影機被淹沒；

and the entire lake that we had been sampling

而我們一直在調查的湖

vaporizes completely.

完全蒸發了。

But I also want to be clear

但我必須聲明，

that we were pretty sure this was not going to happen

我們在火山裡工作的那天，

on the day that we were actually in the volcano,

是非常確定這樣的事情不會發生的，

because Costa Rica monitors its volcanoes very carefully

因為哥斯大黎加透過 OVISICORI 機構

through the OVSICORI Institute,

嚴密地監控火山動態，

and we had scientists from that institute with us on that day.

當時也有幾位該機構的科學家陪同。

But the fact that it erupted illustrates perfectly

而這個它噴發的事實完美地說明了

that if you want to look for where carbon dioxide gas

如果你要找尋二氧化碳氣體

is coming out of this oceanic plate,

是從這個海洋板塊的何處釋放，

then you should look no further than the volcanoes themselves.

那你應該從火山本身找尋。

But if you go to Costa Rica,

但如果你到哥斯大黎加，

you may notice that in addition to these volcanoes

你可能會注意到除了這些火山之外，

there are tons of cozy little hot springs all over the place.

還有非常多小型溫泉。

Some of the water in these hot springs is actually bubbling up

實際上有些溫泉水是從

from this deeply buried oceanic plate.

這個深埋的海洋板塊冒上來的。

And our hypothesis was that there should be carbon dioxide

而我們提出的假說是二氧化碳

應該也跟著一起冒上來，

bubbling up with it,

but something deep underground was filtering it out.

但地底下的某個東西把它過濾掉了。

So we spent two weeks driving all around Costa Rica,

於是我們花兩週的時間 在哥斯大黎加到處繞，

sampling every hot spring we could find --

調查我們所能找到的每一座溫泉——

it was awful, let me tell you.

我跟你說，這經驗很糟。

And then we spent the next two years measuring and analyzing data.

接著我們花兩年的時間 測量和分析這些資料。

And if you're not a scientist, I'll just let you know that the big discoveries

若你不是科學家，我就直接告訴你，

重大的發現通常不會發生在

don't really happen when you're at a beautiful hot spring

你身處美麗的溫泉或站在講台上時；

or on a public stage;

they happen when you're hunched over a messy computer

而通常發生在 你弓著背在雜亂的電腦前，

or you're troubleshooting a difficult instrument,

在檢修一個複雜儀器中，

or you're Skyping your colleagues

或因對資料毫無頭緒

because you are completely confused about your data.

而和同事視訊時。

Scientific discoveries, kind of like deep subsurface microbes,

就好像地表深層的微生物，

can be very, very slow.

科學發現可能進展得非常、非常慢。

But in our case, this really paid off this one time.

但就我們的經驗來說， 這次真的有所斬獲。

We discovered that literally tons of carbon dioxide

我們發現真的有好幾噸的二氧化碳

were coming out of this deeply buried oceanic plate.

從這個深埋的海洋板塊排放出來。

And the thing that was keeping them underground

而讓它們留在地底下，

and keeping it from being released out into the atmosphere

不讓它們釋放到大氣層的，

was that deep underground,

位於地底深處的東西，

underneath all the adorable sloths and toucans of Costa Rica,

在所有哥斯大黎加的 可愛樹懶與巨嘴鳥之下，

were chemolithoautotrophs.

是化能自養生物。

These microbes and the chemical processes that were happening around them

這些微生物與周遭進行化學反應，

were converting this carbon dioxide into carbonate mineral

將二氧化碳轉換成碳酸鹽，

and locking it up underground.

並將它們固定在地底。

Which makes you wonder:

這讓你思考：

If these subsurface processes are so good at sucking up

如果這些地底下進行的反應

如此擅長吸收 所有在其底下的二氧化碳，

all the carbon dioxide coming from below them,

could they also help us with a little carbon problem

它們能不能幫助我們解決

we've got going on up at the surface?

地表上的碳排放問題？

Humans are releasing enough carbon dioxide into our atmosphere

人類已釋放太多二氧化碳到大氣層，

that we are decreasing the ability of our planet

以致削弱了地球

to support life as we know it.

支持生命的能力。

And scientists and engineers and entrepreneurs

科學家、工程師、和企業家

are working on methods to pull carbon dioxide

在想辦法將二氧化碳

out of these point sources,

從這些直接來源抽出，

so that they're not released into the atmosphere.

如此它們就不會被排放到大氣層中。

And they need to put it somewhere.

而它們必須被存放在某個地方。

So for this reason,

基於這個原因，

we need to keep studying places where this carbon might be stored,

我們必須繼續研究 這些碳可能存放的地方，

possibly in the subsurface,

可能是地底，

to know what's going to happen to it when it goes there.

我們必須知道把它存在那裡會怎樣。

Will these deep subsurface microbes be a problem because they're too slow

會因為這些地表深層的微生物 長得太慢，無法實際存放，

to actually keep anything down there?

而變成問題嗎？

Or will they be helpful

還是會因為它們幫忙轉換這東西

because they'll help convert this stuff to solid carbonate minerals?

成為固態的碳酸鹽而有用呢？

If we can make such a big breakthrough

如果我們藉著

just from one study that we did in Costa Rica,

在哥斯大黎加的研究而有所突破，

then imagine what else is waiting to be discovered down there.

想像一下還有什麼 在地底下等著被發現。

This new field of geo-bio-chemistry, or deep subsurface biology,

這個全新的地理—生物—化學 或地底深層生物學，

or whatever you want to call it,

隨便你怎麼稱呼它，

is going to have huge implications,

即將帶來新的啟示，

not just for mitigating climate change,

不光是減緩全球暖化，

but possibly for understanding how life and earth have coevolved,

也可能讓我們了解 生命與地球是如何一起演化的，

or finding new products that are useful for industrial or medical applications.

或許發現工業、醫學上 有用的全新物質，

Maybe even predicting earthquakes

甚至還可能預測地震、

or finding life outside our planet.

找尋外星生命。

It could even help us understand the origin of life itself.

它還能幫助我們了解生命的起源。

Fortunately, I don't have to do this by myself.

幸運的是，我不需要自己完成這件事。

I have amazing colleagues all over the world

我在世界各地都有很棒的同事們，

who are cracking into the mysteries of this deep subsurface world.

他們解開地底深處世界的謎。

And it may seem like life buried deep within the earth's crust

深埋在地殼底下的生命看似

is so far away from our daily experiences that it's kind of irrelevant.

離我們的日常生活遙遠而不相關，

But the truth is that this weird, slow life

但事實上這些奇異緩慢的生命

may actually have the answers to some of the greatest mysteries

可能會是解開

地球上一些生命之謎的關鍵。

of life on earth.

Thank you.

謝謝。

(Applause)

（掌聲）