UV-Resistant Micro-Organisms Discovered In the Stratosphere

junglee_iitk writes "Three new species of bacteria, which are not found on earth and highly resistant to ultraviolet radiation, have been discovered in the upper stratosphere by some Indian scientists. These bacteria, which do not match any species on earth, were found in samples collected through a balloon sent up to the stratosphere in April 2005. The payload consisted of a cryosampler containing 16 evacuated and sterilised stainless steel probes. Throughout the flight, the probes remained immersed in the liquid neon to create a 'cryopump effect.' These cylinders after collecting air samples from different heights ranging from 20 to 41 km were parachuted down and safely retrieved, it said." Here's the Indian Space Research Organisation's press release on the discovery. Adds an anonymous reader: "This paper in International Journal of Astrobiology [PDF] speculates how microorganisms reach the stratosphere."

Comments

Atmosphere of Venus?

[Ihlosi]

Who knows what we'll find in the upper atmosphere of Venus. Maybe we've been looking for life in the wrong places all alon.

Astrobiology paper is not an experimental result.

[Hozza]

I checked the linked paper, from 2005, and while is presents some interesting arguments, it is not a thorough discussion of the subject.

Too many possibilities of Earth origin are rejected with the phrase "it seems unlikely", and there's no mention of the most obvious method by which the micro-organisms get there: random motion (OK, particle velocities in the atmosphere will not be truly random, but you'd still expect a few outliers with very high velocities.)

So, their conclusions may not necessarily be wrong, but they need to do a few more experiments before making a convincing argument that they're right.

(P.S. yes I am a professional Astrophysicist)

What the hell do they eat in the stratosphere?

[Anonymous Coward]

What the hell do they eat in the stratosphere? They must also be able to survive with very little water. Maybe they spend time in lower levels of the atmosphere.

Re:Swell...

[fuzzyfuzzyfungus]

Your point is valid, in that these bugs are probably woefully unsuited to ordinary terrestrial life(even before they make it to our defenses, they'll have to deal with competition from organisms that have evolved to do things other than resist UV all the time).

In some cases, though, resistances do come in packages; because the resistance is obtained by some underlying mechanism that has multiple uses. Things like DNA repair/redundancy mechanisms, or mechanisms for pumping undesirable compounds out of the cell, would qualify.

Deinococcus radiodurans, for instance, has extraordinary resistance to ionizing radiation(as its name suggests); but it is hypothesized that that resistance is an incidental effect of the extreme resistance to dessication that the organism also possesses.

What about Enceladus?

[Kupfernigk]

Not so long ago we had this theory announced that you would only find life on planets in a region between, in effect, too much solar radiation and so little that water only existed as ice, the idea being that this was a small zone and this made life more unlikely. But now there's evidence that there is long term liquid water under a frozen sea on Enceladus, far beyond that zone, and it looks like gravitational forcing may result in relatively high temperatures on many moons of the giant planets. (incidentally Carolyn Porco is now my favourite female scientist.) So in fact it is even possible that life may be most common on moons, because it looks like there are so many of them.

Without any kind of background in the subject (disclaimer disclaimer) I've begun to wonder if the substrate for the emergence of life on Earth may have been carbon nanotubes or graphene on clays, with various oxidising agents as the energy source. This could apply also to remote moons.

Comparable to the surface f Mars

[mbone]

These bacteria were retrieved at "different heights ranging from 20 km to 41 k".

These altitudes bracket the surface pressures on Mars, and the conditions at 41 km are quite comparable to those
on the Martian surface (full UV flux, lower atmospheric pressure).

Given that material is exchanged between the Earth and Mars, I have to wonder if these might not be Martian bacteria.

Panspermia

[smoker2]

There is another article from last year regarding the meteorites found in Antarctica, which were found to be loaded with amino acids. I also remember reading something about actual microbes/bacteria that were found to have entered the atmosphere from space quite recently, but I can't remember the link. It could have been this current story, considering the paper dates from 4 years ago.

I see no reason that this could not be valid. Comets and asteroids have near misses with planets quite regularly and the occasional glancing blow will surely take some of whatever is on the planet out into space. As the paper states, these micro-organisms are viable but don't respond to culturing. Which could mean they were alive but are dormant and don't respond to conditions here on earth.

Being previously undiscovered doesn't really prove anything as the Amazon is full of insects and other life that have yet to be "discovered" by man, but this is not definitively disproving panspermia. IMHO, this is one of the prime reasons for humans to visit Mars, as it is very difficult to get a robot to be able to spot these kinds of organisms, especially if they are not currently alive. The conditions on Mars are not favourable for large organisms, but if there is water ice, then you have the capability of getting H2 and O2 at the least. And as Mars has no magnetic field (to speak of), there would be large amounts of mutating cosmic rays hitting the surface continually for billions of years. It would be odd if nothing came of it.

I've been reading some of Asimovs later scientific essays, and he describes how you can predict with some certainty which planets are likely to have a magnetosphere. Basically, you need a reasonably rapid rotation, and a molten or high temperature metallic core which "sloshes" about as the planet spins. This core acting against the outer layers of the planet causes the magnetic field. The only real reason our planet is special, regarding life, is that we have an exceptionally large moon, too large in fact as conventional wisdom goes, to have been formed by capturing passing debris. We are almost a binary planet system, and that is pretty rare. So the possibility of life forming actually in space (rather than on another planetary body) has to be considered.

If we send men to Mars and they find similar micro-organisms there, then it is possible they came from space rather than evolved natively. Especially if there are no other traces of activity that can be construed as being the result of living organisms.

Interesting stuff, which can never be verified while we sit here exploring from a distance.

Re:Panspermia

[Entropy2016]

As the paper states, these micro-organisms are viable but don't respond to culturing. Which could mean they were alive but are dormant and don't respond to conditions here on earth.

Whoa, woah there buddy. Did you consider the possibility that maybe they "don't respond to culturing" because bacteria that exclusively exist in an upper atmosphere don't like being stuck to a semi-wet petri dish at 1 atmosphere of pressure? They're totally different environments. Granted, I doubt their culturing technique was honestly as crude as conventional petri dish work, but I was making a general point about it being likely a limitation of "how" they tried to culture it.

When you make the agar or whatever medium you plan to use to cultivate any microscopic critter en masse, you're inevitably going to create a selection pressure (sometimes on purpose, sometimes it's a side effect), depending on what nutrients it supplies. I've glanced at a lengthy catalogue of agars I once saw in a microbiology lab. There's a lot of types, but they need them all for different situations. Again, I have no clue how they tried to culture them, but I'm guessing stratospheric microbiology is a relatively new thing, so I wouldn't expect the culturing techniques to be as good they should be for this purpose.

On top of that, from what I understood, we can only culture a surprisingly small fraction of microorganisms anyway. Also, culturing extremophiles has always been very hard. And I'm pretty sure this one counts as an extremophile.

There are going to be plenty of terrestrial explanations for them being uncultivable which do not lend any support to them having a population outside of Earth's biosphere.

Re:How far away is the stratosphere?

[bgray54]

The stratosphere is about 8-15 km above sea level, depending on latitude. To put this in perspective, the top of Mt. Everest is two-ish km shy of the stratosphere.

Re:Astrobiology paper is not an experimental resul

[stiggle]

Random motion might be a method if it wasn't for the tropopause - which they mention. What they do not mention is the other more likely cause - the amount of stuff humans throw up into the atmosphere, as all of their data comes from after the start of the Space Age.

Space craft, supersonic aircraft and weather balloons all regularly go into the stratosphere and could carry particles. 10 years of bacterial evolution would be enough to develop some UV resistance (if we work from the bacteria being deposited there in the late 60's and then sampled in 1978).

Re:They're coming !

[vertinox]

Most extremophiles are so adapted to their environment that they can survive but have a hard time reproducing in more conventional environments.

I think people tend to think simple organism (like single cell bacteria) can evolve to grow into organisms that are immune to everything, but in reality they have limited DNA to work with until they evolve into a more complex organism which tend to not be able to adapt as easy.

Case in point, bacteria that live in the gas vents in pitch black almost boiling temperatures will not live if you brought it the surface area where it is cooler and has more sunlight.

If by the small chance you brought the bacteria to the surface waters (and by small, lets say 100 millions years using a sampling of more than trillions of trillions of bacteria) and found some that didn't die because of random mutations allowed them to live there, you still can't take that mutated bacteria and take it back to the bottom of the ocean and expect it to survive in such a location without going through the same process of 100 millions of years of evolution.

Sure, a bacteria that doesn't die in UV can live fine up there, but can it live in an environment of different temperatures, chemical compositions, other bacteria, and almost of infinite things that might just make it die.

And if by the off chance it does evolve to where it survives in our environment, who is to say that it won't loose its mutation of the UV resistance. There aren't any UV rays down here, and that is just wasted DNA and natural selection won't kill off any bacteria that mutated and lost its resistance so they'll continue to multiply.

As an aside, this is one of the key reasons I argue that hand sanitizers don't actually make "super bugs". Your insides aren't made of soap and alcohol and you don't drink purell when you are sick. So if a bacteria got immune to a hand sanitizer, then it really doesn't make a difference if it is inside of you.

What you should be concerned about is the over use of anti-biotics since that is what you take when you are already infected in which would be a common environment that doesn't have a major evolutionary hurdle to jump.