Shahla Farzan: This is Scientific American’s 60-Second Science. I’m Shahla Farzan.
Shahla Farzan：这里是《科学美国人》的 60 秒科学。我是Shahla Farzan。
A couple billion years ago—about three billion to be a little more precise—the earth was a very different place. It had vast oceans and almost no oxygen in the atmosphere. It was a place where bacteria ruled.
几十亿年前——更准确地说大约是 30 亿年前——地球是一个非常不同的地方。它有广阔的海洋，大气中几乎没有氧气。这里还是一个细菌统治的星球。
Some of these bacteria used photosynthesis to power themselves, kind of like plants. But they did it in a strange way: by harnessing light and stealing electrons from iron.
其中一些细菌利用光合作用为自己提供动力，有点像植物。但他们以一种奇怪的方式做到了：它们利用阳光，从铁中“偷取”电子。
Fast-forward about two billion years, and those bacteria still exist today. They’re called photoferrotrophs, and for decades, scientists thought they were pretty rare.
快进大约 20 亿年，这些细菌今天仍然存在。它们被称为光铁养菌(photoferrotroph)，几十年来，科学家们认为它们非常罕见。
Arpita Bose: Most people think these are exotic organisms that do other things and photoferrotrophy is just something that they might have retained from the past, during early earth history.
Arpita Bose： 大部分人认为，这些奇异的有机体还有其他功能，光铁自养只不过是从遥远的过去，即地球早期历史中保留下来的技能。
Farzan: Arpita Bose is a microbiologist at Washington University in St. Louis.
Farzan： Arpita Bose是圣路易斯华盛顿大学的微生物学家。
In 2015, on a whim, Bose collected some vials of marine sediment from Woods Hole, Mass., and brought them home to her lab in Missouri.
2015 年，Bose 一时兴起从马萨诸塞州的伍兹霍尔收集了一些小瓶的海洋沉积物，并将它们带回了她在密苏里州的实验室。
Her students slowly parsed out the individual strains of bacteria, and they started testing them, one by one, trying to figure out if any of them still had that ancient metabolism.
她的学生们慢慢地分析出个别的细菌菌株，然后他们开始一一测试，试图弄清楚其中是否有些细菌仍具有这种古老的代谢模式。
Bose still remembers the day two of her students came into her office with the results.
Bose 仍然记得她的两个学生带着结果来到她办公室的那一天。
Bose: And they were like, “They all do it. They all do photoferrotrophy.” And I was like, “What?! No way! No way.” I was kind of shocked [laughs].
Bose：“他们告诉我：‘所有细菌都是如此!它们都是光铁养的。’而我的反应则是：‘什么?!不可能!绝不可能。’我都惊呆了。”
Farzan: All 15 bacterial strains were photoferrotrophs. Maybe, they started thinking, this trait wasn’t that rare after all.
Farzan：所有这15种细菌菌株都是光铁养菌，他们不禁想到，这一性状也许根本不少见。
The study appears in the [ISME Journal]: Multidisciplinary Journal of Microbial Ecology. [Dinesh Gupta et al., Photoferrotrophy and phototrophic extracellular electron uptake is common in the marine anoxygenic phototroph Rhodovulum sulfidophilum]
该研究发表在 [ ISME 期刊]：《国际微生物生态学会杂志》上。[Dinesh Gupta 等，光养铁和光养细胞外电子摄取在海洋无氧光养红酵母中很常见]
A big reason why they care—beyond just basic scientific curiosity—is the fact that these microbes are vacuuming up carbon dioxide as they photosynthesize.
除了基本的科学好奇心之外，他们关心的一个重要原因是这些微生物在进行光合作用时会吸收二氧化碳。
Bose: If this is truly as common as our data suggests they are, it’s possible that these organisms do make a massive contribution to carbon dioxide fixation as well.
Bose：如果这真的像我们的数据表明的那样普遍，那么这些生物也可能对二氧化碳的固定做出了巨大的贡献。
Farzan: That means preserving the wetlands and estuaries where these bacteria thrive could be an important component of combating climate change.
Farzan：这意味着保护这些细菌繁衍的湿地和河口可能是应对气候变化的重要组成部分。
Right now, those habitats are rapidly disappearing, says Michael Guzman, a microbiologist at Lawrence Livermore National Laboratory and one of the study co-authors.
劳伦斯利弗莫尔国家实验室的微生物学家、该研究的合著者之一迈克尔古兹曼说，现在，这些栖息地正在迅速消失。
Guzman: These environments are a hotbed for biological diversity. There’s a lot of things happening in these environments that we still don’t know about. So I think preserving these natural microbial communities is really important.
古兹曼： 这些环境是生物多样性的温床。在这些环境中发生了很多我们仍然不知道的事情。所以我认为保护这些天然微生物群落非常重要。
Farzan: For Scientific American’s 60-Second Science, I’m Shahla Farzan.
Farzan：《科学美国人》的 60 秒科学，我是 Shahla Farzan。
Shahla Farzan: This is Scientific American’s 60-Second Science. I’m Shahla Farzan.
A couple billion years ago—about three billion to be a little more precise—the earth was a very different place. It had vast oceans and almost no oxygen in the atmosphere. It was a place where bacteria ruled.
Some of these bacteria used photosynthesis to power themselves, kind of like plants. But they did it in a strange way: by harnessing light and stealing electrons from iron.
Fast-forward about two billion years, and those bacteria still exist today. They’re called photoferrotrophs, and for decades, scientists thought they were pretty rare.
Arpita Bose: Most people think these are exotic organisms that do other things and photoferrotrophy is just something that they might have retained from the past, during early earth history.
Farzan: Arpita Bose is a microbiologist at Washington University in St. Louis.
In 2015, on a whim, Bose collected some vials of marine sediment from Woods Hole, Mass., and brought them home to her lab in Missouri.
Her students slowly parsed out the individual strains of bacteria, and they started testing them, one by one, trying to figure out if any of them still had that ancient metabolism.
Bose still remembers the day two of her students came into her office with the results.
Bose: And they were like, “They all do it. They all do photoferrotrophy.” And I was like, “What?! No way! No way.” I was kind of shocked [laughs].
Farzan: All 15 bacterial strains were photoferrotrophs. Maybe, they started thinking, this trait wasn’t that rare after all.
The study appears in the [ISME Journal]: Multidisciplinary Journal of Microbial Ecology. [Dinesh Gupta et al., Photoferrotrophy and phototrophic extracellular electron uptake is common in the marine anoxygenic phototroph Rhodovulum sulfidophilum]
A big reason why they care—beyond just basic scientific curiosity—is the fact that these microbes are vacuuming up carbon dioxide as they photosynthesize.
Bose: If this is truly as common as our data suggests they are, it’s possible that these organisms do make a massive contribution to carbon dioxide fixation as well.
Farzan: That means preserving the wetlands and estuaries where these bacteria thrive could be an important component of combating climate change.
Right now, those habitats are rapidly disappearing, says Michael Guzman, a microbiologist at Lawrence Livermore National Laboratory and one of the study co-authors.
Guzman: These environments are a hotbed for biological diversity. There’s a lot of things happening in these environments that we still don’t know about. So I think preserving these natural microbial communities is really important.
Farzan: For Scientific American’s 60-Second Science, I’m Shahla Farzan.
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