UV-C Light Kills Nearly Everything - Except This Unusual Organism (science.org) 41
"Earth's ozone layer blocks the Sun's shortest wave radiation, called UV-C, which is so damaging to cells in high doses that it's a go-to sterilizer in hospitals," writes Slashdot reader sciencehabit. "UV-C is such a killer, in fact, that scientists have questioned whether life can survive on worlds that lack an ozone layer, such as Mars or distant exoplanets.
"But research published this month in Astrobiology suggests one hardy lichen, a hybrid organism made of algae and fungi, may have cracked the UV-C code with a built-in sunscreen, despite never experiencing these rays in its long evolutionary history."
Science magazine explains: When scientists brought a sample of the species, the common desert dweller Clavascidium lacinulatum, back to the lab, graduate student Tejinder Singh put the lichen through the wringer. First, Singh dehydrated the lichen, to make sure it couldn't grow back in real time and mask any UV damage. Then he placed the lichen a few centimeters under a UV lamp and blasted it with radiation. The lichen seemed just fine.
So Singh purchased the most powerful UV-C lamp he could find online, capable of sending out 20 times more radiation than the amount expected on Mars. When he tested the lamp on the most radiation-resistant life form on Earth, the bacterium Deinococcus radiodurans, it died in less than a minute. After 3 months—likely the highest amount of UV-C radiation ever tested on an organism—Singh pulled the sample so he could finish his master's thesis in time. About half of the lichen's algal cells had survived. Then, when the team ground up and cultured part of the surviving lichen, about half of its algal cells sprouted new, green colonies after 2 weeks, showing it maintained the ability to reproduce.
The species may provide a blueprint for surviving on Mars or exoplanets, which don't have an ozone layer to protect them.
"But research published this month in Astrobiology suggests one hardy lichen, a hybrid organism made of algae and fungi, may have cracked the UV-C code with a built-in sunscreen, despite never experiencing these rays in its long evolutionary history."
Science magazine explains: When scientists brought a sample of the species, the common desert dweller Clavascidium lacinulatum, back to the lab, graduate student Tejinder Singh put the lichen through the wringer. First, Singh dehydrated the lichen, to make sure it couldn't grow back in real time and mask any UV damage. Then he placed the lichen a few centimeters under a UV lamp and blasted it with radiation. The lichen seemed just fine.
So Singh purchased the most powerful UV-C lamp he could find online, capable of sending out 20 times more radiation than the amount expected on Mars. When he tested the lamp on the most radiation-resistant life form on Earth, the bacterium Deinococcus radiodurans, it died in less than a minute. After 3 months—likely the highest amount of UV-C radiation ever tested on an organism—Singh pulled the sample so he could finish his master's thesis in time. About half of the lichen's algal cells had survived. Then, when the team ground up and cultured part of the surviving lichen, about half of its algal cells sprouted new, green colonies after 2 weeks, showing it maintained the ability to reproduce.
The species may provide a blueprint for surviving on Mars or exoplanets, which don't have an ozone layer to protect them.
7 things about unusual organisms (Score:1)
2. Clickbait headlines are now used at
Etc
Re: (Score:2, Funny)
says the guy with the username Bang Whorey Gonorrhea.
Makes sense. (Score:4, Interesting)
It makes sense. Clavascidium laciniatum forms a biological soil crust in harsh areas like Joshua Tree. And it's incredibly slow growing. So the rate at which it accumulates UV damage versus the rate at which it can repair itself is super-high. Hence it's been under intense selective pressure to develop good resistance to the ionizing radiation damage caused by UV.
Re:Makes sense. (Score:5, Interesting)
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It's a shame that safe UVC lamps (222nm) are still expensive and need moderately high voltages to work. We could be disinfecting a lot of stuff with them if they were more common.
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It's a shame that safe UVC lamps (222nm) are still expensive and need moderately high voltages to work. We could be disinfecting a lot of stuff with them if they were more common.
They’re not cheap probably for the same reason your hairdryer comes with an LMMT (Legally Mandated Moron Tag) on it that reads “Do Not Use In Bathtub”.
We should probably be thankful. Can’t imagine how bad a Temu disinfecting bench would be at tanning, but plenty of morons would find out.
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Yeah, I once looked into them and got sticker shock :P That said, the prices are coming down. The research seems to continue to show that they're safe for humans (although from the data I've seen I doubt they're safe for houseplants; their cuticle is much thinner than our skin). But for us... it can't penetrate dead skin, and while the outer layers of our eyes are alive, the cells there are constantly being shed and replaced.
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Not with far-UV (~222nm) you didn't.
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You can't get sunburned from far-UV like you can with normal UVC. It doesn't penetrate deep enough to reach living skin cells (e.g. the (dead) stratum corneum is 10-40 microns on most skin, up to hundreds on e.g. palms and soles) - in human tissue, 222nm penetrates only a few microns, with most of the energy deposited in the first micron; the deepest any degradation was seen in one study was 4,6 microns [nih.gov] (for 233nm, it's 16,8 microns). As mentioned earlier, the only cells it can kill are the outermost layer
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ED: Last time I looked (when the tech was brand new) I couldn't find any studies on plants, but there apparently are now, and... yeah, it's what I expected [springer.com]. In fact, it's even worse than I expected: because all the energy is absorbed in such a short distance (the (living) epidermal layer), it does a lot more damage in that (critical) layer.
That said, apparently at lower doses you can still kill fungal pathogens without hurting the plants [sciencedirect.com], and is much more effective at doing so, there is that.
I wonder if we
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UV kills all the life (Score:3, Funny)
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Lichen likes the light (Score:2)
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https://www.youtube.com/watch?... [youtube.com]
UV-C not shortest (Score:1, Offtopic)
It is embarrassing when a reputable science website makes ridiculous claims like UV-C is the shortest wavelength radiation the sun produces. Perhaps the editors have never heard of x-rays or gamma-rays. And it goes on from there. On the other hand maybe they don't have editors over there anymore, just poorly educated interns supervising AIs making things up. Either way that is kind of sad though.
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It is embarrassing when a reputable science website makes ridiculous claims like UV-C is the shortest wavelength radiation the sun produces
That is from tfa. It just goes to show that Science and Nature are just academic tabloid rags these days.
Re:UV-C not shortest (Score:4, Interesting)
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Re:UV-C not shortest (Score:4, Informative)
The Sun doesn't emit much X-rays or gamma rays. Nearly all (like way above 99%) of the Sun's radiated energy is UV and lower frequency. The Sun's X-rays or gamma rays are not enough to be dangerous.
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It is embarrassing when a reputable science website makes ridiculous claims like UV-C is the shortest wavelength radiation the sun produces. Perhaps the editors have never heard of x-rays or gamma-rays. And it goes on from there. On the other hand maybe they don't have editors over there anymore, just poorly educated interns supervising AIs making things up. Either way that is kind of sad though.
You’re right. It is embarrassing. Almost as embarrassing as coming across as a damn grammar nazi when it comes to the shortest UV wavelength.
And since the ENTIRE fucking story is centered around UV, perhaps the editors assumed a level of intelligence among the readers. They were clearly wrong.
Good to know (Score:3)
The species may provide a blueprint for surviving on Mars or exoplanets, which don't have an ozone layer to protect them.
Good to know. I'll get started on modifying my DNA to match right away. Elon, I'm coming!
Re:Good to know (Score:5, Funny)
Elon, I'm coming!
I thought I had lost faith in Slashdot, but here is a phrase never previously uttered by humans, truly this place has value.
Re:Good to know (Score:4, Funny)
Elon, I'm coming!
I thought I had lost faith in Slashdot, but here is a phrase never previously uttered by humans, truly this place has value.
You assume that Elon, wasn’t talking to Elon.
That’s a pretty strong assumption.
Re: Elon, I'm coming! (Score:2)
Wasn't that a song by Three Dog Night?
Re:Good to know (Score:4, Interesting)
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so think research like this is valuable.
Absolutely. I wasn't making fun of the research, I was making fun of the summary; a longstanding Slashdot tradition.
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I think it was Carl Sagan that proposed that we send hardy microbes to Mars in order to start a terraforming process.
What's the point, since Mars doesn't have a significant enough magnetic field to hold anything resembling an atmosphere? Isn't that the whole reason Mars is the planet it is today? It's dynamo stopped a long time ago.
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I think it was Carl Sagan that proposed that we send hardy microbes to Mars in order to start a terraforming process.
What's the point, since Mars doesn't have a significant enough magnetic field to hold anything resembling an atmosphere? Isn't that the whole reason Mars is the planet it is today? It's dynamo stopped a long time ago.
Perhaps you misunderstood. The key word, is hardy. As in what microbes would have to adapt to in order to help create life on a planet that has changed dramatically. That’s not trying to win back the atmosphere. It’s more creating a solution that accommodates the lack of one.
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I believe that the math supports creating a biosphere that would persist on human timescales, just not geologic ones.
IE we could create an atmosphere that would last for 10K years, but would eventually be stripped in 1M years.
If that's worth the effort remains to be seen, but some do think that yes it might be.
Lucky we didn't trash the ozone layer (Score:3)
I have to admit, I wasn't expecting something I've mainly heard of as reindeer food to be such a hardcore survivor.
What can I say...I'm lichen it!
Mars doesn't have an ozone layer (Score:3)
No more click bait headlines please (Score:3)
Why is it "UV-C Light Kills Nearly Everything - Except This Unusual Organism"? Would not "UV-C Light Kills Nearly Everything - Except Lichen" be shorter and more informative? But then that means people get the information they need without having to click on a link.
The use of click bait used to be limited to shady news outlets and "entertainment news" (in scare quotes because most anything out of the entertainment business is more rumor than actual news) but now it is a practice seen by what used to be respected news outlets. If Slashdot wants to maintain an image of being a respectable source of news then the editors should take the minimal effort of editing headlines to remove click bait tactics.