评论
打印
Thanks to Brilliant for supporting this episode of SciShow.
感谢Brilliant对本期节目的支持。
Go to Brilliant.org/SciShow to learn how you can take your STEM skills to the next level!
登录Brilliant.org/SciShow了解如何将你的STEM技能提升到下一个水平！
Ever since humans found out germs were a thing, we've had a vendetta against microbes.
自从人类发现细菌以来，我们就对微生物结下了仇。
The idea that death can be doled out by stuff we can't even see is pretty unsettling.
死亡可以由我们看不见的东西来决定，这种想法令人不安。
So we invented antibacterial soap and antibiotics and antifungals,
所有我们发明了抗菌皂、抗生素和抗菌剂，
and we went a little bit overboard in the end with the anti-everythings.
最后，我们在“反一切”上做得有点过火了。
And as a result, we've often ignored the existence of good microbes.
因此，我们常常忽略了有益微生物的存在。
With the exception of the ones that give us cheese and yogurt and beer and bread, of course.
当然，除了那些给我们提供奶酪、酸奶、啤酒和面包的菌类。
We've always given them a free pass. But good microbes do a lot more than make yogurt yogurty and cheese cheesy.
我们总是给它们一张免费的通行证。但有益微生物的作用远不止酸奶和奶酪。
They also help us digest food and fight illness.
它们还帮助我们消化食物，对抗病毒。
And the more we've learned about them, the more we've realized that they have the capacity to do really big things.
我们对它们了解的越多，就越意识到它们有能力做大事。
Like help us protect endangered species and maybe even undo some of the big mistakes we have made as humans.
比如帮助我们保护濒危物种，甚至可能弥补我们作为人类犯下的一些重大错误。
So here are six examples of microbes helping to save the world. The first, koalas. They are notoriously picky eaters.
以下是细菌帮助我们拯救世界的6个例子。首先是考拉。它们是出了名的挑食。
Although they've occasionally been seen eating leaves from other trees, for the most part, they eat eucalyptus leaves.
虽然它们有时候吃其他树上的树叶，但它们主要以桉树叶为食。
And that's pretty much it. And they're even picky about which species of eucalyptus they eat.
差不多就是这样了。它们甚至对吃哪种桉树都很挑剔。
So, these things are cute, but they're also, like, the worst dinner guests of all time.
这些东西很可爱，但它们也是有史以来最糟糕的食客。
Thankfully, that's not too much of an issue for them.
还好，这对它们来说并不是什么大问题。
Australia is full of eucalyptus trees, and there isn't a lot of competition for it since the plant's leaves are toxic.
澳大利亚桉树很多，由于这些树叶有毒，所以竞争也很少。
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.
由于考拉只能通过一种特殊的肠道菌来消化桉树叶——考拉会在小时候吃一种被称为pap的食物来获取这种肠道菌。
That's a special kind of microbe-rich poop that they get from their moms.
这是一种特殊的富含微生物的便便，来自它们的妈妈。
So overall, this lifestyle works for them. Or it did. In the next sixty years,
所以总的来说，这种生活方式对它们是有效的。在接下来的60年里，
climate change is expected to reduce the distribution of most Australian eucalyptus species by more than half.
气候变化预计将使澳大利亚大部分桉树物种的分布减少一半以上。
Urbanization and habitat destruction are also a threat, and that was before the devastating Australian wildfires
城市化和毁坏栖息地也是威胁，这是在澳大利亚毁灭性的野火
(which started in 2019) added even more pressure. In response to this,
（始于2019年）带来更大压力之前。因此，
you would think koalas might switch to another food source. But they don't always do that — in part,
你或许认为考拉可能会选择另一种食物来源。但它们不会——
because their digestive systems are just so specialized to one or a few species of eucalyptus. Fortunately, there's a pap for that.
部分原因是因为它们的消化系统只专门适用于一种或几种桉树。还好有pap。
In 2019, scientists successfully transplanted the gut bacteria from koalas who ate one type of eucalyptus,
2019年，科学家们成功地将食用斜叶桉树叶考拉身上的肠道菌
called messmate, into the guts of those who were used to eating another type, called manna gum.
移植到了习惯吃另一种叫做多枝桉的考拉的肠道中。
Specifically, they gave the manna gum koalas capsules that contained microbes extracted from the poop of messmate koalas.
具体来说，他们给了多枝桉考拉一种胶囊，胶囊中含有从斜叶桉考拉粪便中提取的微生物。
Which is like, you know, slightly less gross than eating actual poop.
这就比吃真正的便便稍微没那么恶心。
The scientists hoped that the unique microbes from the messmate koalas would help the other group's bodies digest the new food.
科学家们希望从斜叶桉考拉身上提取出的独特细菌可以帮助其他考拉消化新食物。
And at the end of the experiment, the manna gum eaters were eating more messmate. So… success!
实验最后，多枝桉考拉吃了更多的斜叶桉。所以实验成功啦！
To be fair, though, the researchers weren't totally sure if this happened because of the increase in gut bacteria,
但老实说，研究人员也不完全确定这是因为肠道细菌的增加才会这样，
or if the gut bacteria were increasing because the koalas were eating more messmate for some other reason.
还是出于其他原因，考拉吃了更多的斜叶桉树叶，它们的这种肠道细菌才会增加。
So there's room here for more research.
所以还需要更多研究。
But it's intriguing to think that poop and the bacteria it contains might one day help save a species.
但有趣的是，粪便和粪便中含有的细菌可能有一天会帮助拯救一个物种。
To the delight of poop joke enthusiasts everywhere. Next, malaria is one of humanity's most deadly foes.
这一点各地的便便笑话爱好者应该会高兴。下一个，疟疾是人类最致命的敌人之一。
But we aren't the only species that gets it. Bats, reptiles, birds — there are a lot of animals on malaria's hit list,
但我们并不是唯一一个会得疟疾的物种。蝙蝠、鸟类——很多动物都是疟疾的袭击目标，
although not all of them are affected by it the way we are. Take avian malaria, for example.
虽然不是所有物种都像我们一样受到它的影响。例如，禽疟。
Although it can shorten birds' lives, it usually doesn't kill them.
虽然疟疾会缩短鸟类的寿命，但通常不会致死。
In some isolated places, though, avian malaria can be deadly. Like in Hawai'i.
虽然在一些与世隔绝的地方，禽疟是致命的。比如在夏威夷。
Until humans came along, birds in Hawai'i had no exposure to the malaria parasite —
在人类出现之前，夏威夷群岛的鸟类没有接触过疟原虫，
because there were no mosquitos on the Hawaiian Islands.
因为夏威夷群岛上没有蚊子。
According to a local legend, that only happened when a bunch of sailors dumped a barrel full of water
根据当地传说，当一群水手把一桶水和蚊子幼虫
and mosquito larvae into the wetlands around Lahaina. Which… did that seem like a good idea?
倒进拉海纳附近的湿地时，这种情况才会发生。这看起来是个好主意吗？
When the mosquitos arrived, so did the avian malaria parasite.
蚊子来了，禽疟自然也来了。
And after native Hawaiian birds were introduced to it, ten species went extinct.
本地夏威夷鸟被引进后，有10个物种灭绝了。
Thankfully, there might be a way to control this disease in Hawai'i and all over the world.
值得庆幸的是，在夏威夷和全世界可能有办法控制这种疾病。
And it's not insecticide — because although that's been the standard for years,
不是杀虫剂——因为尽管这是多年来的标准，
mosquitos have an annoying habit of becoming resistant to it.
但蚊子有一个讨厌的习惯——它们对杀虫剂有抵抗力了。
Instead, scientists are testing a new weapon: a bacteria called Wolbachia,
相反，科学家们正在测试一种新武器：一种被称为沃尔巴克氏体细菌，
which naturally infects a lot of other insects, but not malaria-carrying mosquitos.
这种细菌会感染很多其他昆虫，但不会感染携带疟疾的蚊子。
But in a 2009 experiment, scientists took some Wolbachia and managed to infect a group of Aedes aegypti mosquitoes with it.
但在一项2009年的实验中，科学家想用沃尔巴克氏体感染了一群埃及伊蚊。
Those are mosquitos that carry a whole bunch of diseases, including avian malaria.
那些蚊子携带大量疾病，包括禽疟。
Then, they had those mosquitos drink the blood of chickens infected with the avian malaria parasite.
然后他们让这些蚊子吸了感染禽疟原虫的鸡血。
And normally, this would result in the insects becoming malaria carriers.
通常情况下，这会让昆虫成为疟疾载体。
But in this case, the mosquitos actually appeared to have a stronger immune response, and fewer malaria parasites developed.
但在这次实验中，蚊子的免疫系统显然更强，而且疟疾寄生虫的数量也更少了。
Right now, scientists aren't completely sure why this works,
现在，科学家们还不能完全确定为什么会这样，
but it could be because the mosquito's immune system gets a boost in the presence of Wolbachia.
但这可能是因为蚊子的免疫系统在沃尔巴克氏菌的存在下得到了增强。
And as a bonus, this method also works to prevent other diseases,
此外，这种方法还可以预防其他疾病，
including mosquito-borne human ones like dengue and Zika, which are also carried by A. aegypti.
包括由蚊子传播的登革热和寨卡病毒等人类疾病，埃及伊蚊也会传播这些疾病。
If you've ever tried to enjoy a day at one of the Midwest's Great Lakes,
如果你曾经尝试过在美国中西部的五大湖区享受一天，
you may have noticed a bunch of tiny, pokey shells all over the beach.
你可能会注意到海滩上到处都是细小的贝壳。
Those are invasive zebra mussels, and they're there just to ruin your afternoon. Or so it seems like, anyway.
这些是入侵物种，斑马贝，它们的存在只是为了破坏你的下午。至少看起来是这样的。
In reality, invasive mussels are a huge problem not just because it hurts to step on them,
实际上，侵入性斑马贝是一个大问题，不仅因为踩到它们会受伤，
but because they are extremely difficult to control.
也是因为它们难以控制。
Juveniles are microscopic and will attach themselves to almost any hard surface,
它们的幼体很小，几乎可以附着在任何坚硬的表面上，
which means boat owners can accidentally transport them from one lake to another.
这意味着船主可能会不小心把它们从一个湖运到另一个湖。
And when they do, these mussels clog the intake pipes that feed city water supplies, they hog nutrients,
如果这样，这些贻贝堵塞了城市供水的管道，霸占了营养物质，
and they steal food from native fish and other aquatic species.
还从本地鱼类和其他水生物种那里偷取食物。
In the US, they cost the economy around a billion dollars every year.
在美国，它们每年给经济造成约10亿美元的损失。
Fortunately, scientists have figured out how to use the mussels' own diet against them.
幸运的是，科学家弄清楚了如何用贻贝的饮食对抗它们。
See, mussels usually eat plankton, but they also eat bacteria.
贻贝通常吃浮游生物，但它们也吃细菌。
And after testing more than 700 strains, researchers learned that a common,
测试了700多种菌株后，研究人员发现了一种常见的，
usually harmless bacteria called P. fluorescens produces a toxin that's dangerous to the mussel's digestive system.
通常是无害的细菌——萤光假单胞菌会产生一种毒素，对贻贝的消化系统很危险。
It causes cells to rupture and die in the mussels' digestive gland, and that ultimately kills the animal.
它会导致贻贝消化腺的细胞破裂死亡，最终导致动物死亡。
Maybe more importantly, though, when mussels feed on this bacteria,
或者更重要的是当贻贝以这种细菌为食，
they don't notice anything's wrong; they seem to think they're having just a nice and lovely day.
它们不会注意到任何不对劲；它们似乎认为自己的生活很美妙。
And they will keep eating until they die.
它们会一直以此为食，直到死去。
This is huge, because although chemicals like chlorine are a more obvious threat to the animals,
这个很厉害，因为尽管像氯这样的化学物质对动物来说是一个更明显的威胁，
mussels can sense those chemicals and will shut their valves to protect themselves.
但贻贝可以感知这些化学物质，并会关闭阀门来保护自己。
The bacteria, meanwhile, just masquerades as normal food.
而细菌只是伪装成正常的食物。
Scientists have been looking into this biological solution to the invasive mussel crisis for decades,
几十年来，科学家们一直在研究这种生物方法来解决贻贝入侵危机，
but in the last few years, that research has finally started translating into practical use.
但在最近几年，这项研究终于开始转化为实际应用。
So someday, we might be thanking P. fluorescens for our clean, mussel-free beaches.
所以某天我们可能要为干净无贝的海滩感谢萤光假单胞菌。
