Short Wave - Micro Wave: Scientists Discover GINORMOUS Bacteria

Episode Date: June 30, 2022

The Caribbean is home to gorgeous beaches, mangroves and ... the biggest bacteria known to humankind. Find out exactly how big from science correspondent Nell Greenfieldboyce in this Micro Wave. Then, stay for the listener mail, where we answer YOUR questions — all hosted by our new senior editor, Gabriel Spitzer!Do you have a question for Short Wave? Email us a voice memo at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

Hey, short waivers. This is senior editor Gabriel Spitzer, sitting in on the mic today. And I'm here with NPR science correspondent, Nell Greenfield Boys. Hey, Nell. Hey, Gabe. Hey, everybody. So today's story starts off in the waters of the Caribbean. Indeed. There are mangrove trees there. You know those trees, the one with the roots that sort of reach down into the water? And their leaves fall down and collect at the bottom. And they make this kind of, I don't know, like a, like a mat of leaves and decaying debris. And years ago, a researcher went down there to dig through this underwater crud and collect samples. He wanted to understand what kinds of tiny life make their home there. And he found something that he had never seen before growing on these sunken leaves. They looked like white hairs or filaments. He didn't know what they were.

So he brought them back to the lab. And when he looked at them with microscopes, he realized they were missing key features normally found in plant and animal cells, suggesting that these weird things had to be something else. And what they are is really surprising. It's almost shocking, really. It turns out they're bacteria. An analysis of the genetic material found inside them

shows they're related to other bacteria that make a living off sulfur and also can grow large, but not this large. Today on the show, the biggest bacteria ever discovered. It's a microwave episode, even though micro might be kind of a misnomer in this case. Plus, we answer your listener, mail. I'm Gabriel Spitzer.

I'm Nell Greenfield Boyce. And you're listening to Shortwave, the Daily Science podcast from NPR. So when we heard about these gigantic bacteria, we could not resist. And we asked you, Nell, to come in and give us the lowdown. So now, bacteria that are big enough to see. I mean, like, how big are we talking? About a centimeter, a centimeter long. So one of the scientists who's been studying this new bacteria is Jean-Marie Valand from Lawrence Berkeley National Laboratory, as well as the laboratory for research in complex systems.

And he says each bacterium is roughly the same size and shape as an eyelash, a human eyelash. These bacteria are about 5,000 times larger than most bacteria. it is the equivalent for us humans to encounter another human who would be as tall as the Mount Everest. Wow. Yeah, and scientists who study bacteria, even weird bacteria, are completely impressed. One person told me this is a real microbial monster. I mean, that's just very strange when normally you can't even see bacteria. By definition, you can't see microbes.

Micro is in the name. They're microscopic. One scientist said that this is weirdly a bacteria that is not a microbe. Wow. We have to come up with a new name, like a macrobe or something. Yeah, and they reproduce in a funny way. So most bacteria make more of themselves by just dividing in half, and then they produce two identical cells. These bacteria that are long and thin, it seems like the very tip can just kind of like bud off, and then that floats away. and somehow attaches itself some plates else and grows there into another larger bacteria.

Huh. Okay. So, you know, I'm thinking about other kinds of single-celled organisms like protists and stuff like that, but these are not them, right? These are bacteria. How are they different from those other kind of organisms? Well, some single-celled organisms have highly organized innards. They've got like one central nucleus that contains the genetic material and other little organelles like mitochondria. Others like bacteria generally don't have that level of organization, but these bacteria are unusually complex. So, for example, most bacteria let their genetic material float around freely inside. But these wrap it up in lots of little packages. Researchers think this unusual level of organization is what lets this bacteria grow to a size beyond what was thought to be the theoretical limit for how.

how big bacteria can get. Wow. So, okay, here we have these humongous bacteria that we've discovered that are outliers from the whole rest of the kingdom of life. What does this suggest to you about just like what's still out there to be discovered in the microbial universe? I think that, you know, people tend to look for what they're used to. You know, sort of what you see depends on what you know.

And I think for so long, people have assumed that bacteria have to be microscopic. These researchers say that other large bacteria might be hiding in plain sight. So I have to ask, I think your guy called it a microbial monster. I mean, that sounds pretty dramatic, like right up there with super bugs or murder hornets or whatever. But do I need to worry about these things? They are not disease-causing or harmful in any way. The researchers who have been looking at them haven't seen anything suggesting that they could be a danger to basically anything. bacteria get a bad rap, but remember, most bacteria are either completely harmless or even potentially beneficial.

I mean, we need our bacteria. We need our bacteria. All right. Well, thank you for that important reminder and microbial context, Nell Greenfield Boys. Thank you. Thanks for having me on the show. And with that, in our microwave episodes, we always like to answer some listener mail. And today's questions are both very smart and very charming.

First up is Elia, who is seven. What's the best surface for bacteria to grow on? So I had some guesses here, like the hotel room comforter or the back seats of my Subaru, but we thought we should do that thing where we call a smart person who actually knows the answer. And so Rachel Carlson, our intern, called up Aisha Burton. I'm a post-doctoral fellow at the NIH, and I'm currently studying how E. coli, a microorganism found in our gut, response to stress. And Ayesha says, it depends on the organism. We can't just narrow it down just to one surface because different bacteria love to grow on different surfaces.

We have bacteria in our gut growing and expanding. We have bacteria like Staph aureas on our skin. We can't see it, but it's there. Bacteria are everywhere. So we just can't say they grow in just one condition. So there you have it. Bacteria, like people, thrive in many different places. So our second question comes from Arjun, who is 12.

years old. Are there tectonic plates on other planets? This is a really good question. So for this, we turn to Katie Cooper, an associate professor in the School of the Environment at Washington State University. Yes, other planets have tectonic plates, but some planets likely only have one single plate that spans the entire planet and isn't doing that much like the Earth's plates, which are interacting, causing earthquakes and mountains and volcanoes. However, some other planets or planetary bodies like Europa may have experienced past behavior of individual plates interacting with each other, and we can get that information from the surface history. You don't have to be a delightful child to send us your science questions.

I mean, it helps. Share your curiosity with us by emailing shortwave at npr.org. This episode was produced by the fabulous Burley McCorm. edited by Rebecca Ramirez and fact-checked by Rachel Carlson. The audio engineer was Natasha Branch. Giselle Grayson is our senior supervising editor. Andrea Kissick runs the science desk. Edith Chapin is vice president and executive editor at large. Terrence Samuel is vice president and executive editor.

And Nancy Barnes is our senior vice president of news. I'm Gabriel Spitzer. Thanks for listening to Shortwave from NPR.