New Microbes Found in Antarctica

[Hashi Lebwohl]

Here is the article I found via the weekly Mensa newsletter. The article contains a link to the source article published in Nature.

Biologists have extracted mineral-eating microbes from a lake buried a half mile below the surface of the West Antarctic Ice Sheet, according to a new study published in Nature.

Earlier claims of similar microbes drawn from a different Antarctic lake, say the study's authors, were controversial because the samples had been contaminated—a problem eliminated in this case by especially careful drilling techniques.

"The report is a landmark for the polar sciences," writes Martyn Tranter, a geochemist at the University of Bristol, England, who was not involved in the study, in a commentary also published in Nature.

It's also a landmark in the science of astrobiology, the search for life on other worlds. In recent years, scientists have come to understand that life can thrive in a much wider range of environments than they once believed, including superheated water at the bottom of the ocean and ice caves in Greenland. That suggests that extraterrestrial life might also exist in places once thought uninhabitable.

This new identification of microbes in subglacial Lake Whillans, a 6-foot-deep, 20-square-mile (1.8 meters, 52 square kilometers) body of water kept liquid by heat from the bedrock below and friction from glaciers moving over that bedrock, just adds to the possibilities. The authors' findings, Tranter writes, "beg the question of whether microbes could eat rock beneath ice sheets on extraterrestrial bodies such as Mars."

The Lake Whillans microbes, which come from nearly 4,000 distinct species or "operational taxonomic units" (groups of species with similar characteristics), are chemoautotrophs, meaning they get their energy not from sunlight nor from other organisms that live on sunlight, but rather from minerals dissolved in the water, including nitrites, iron, and sulfur compounds.

Given their ability to exist without light or access to organic food sources, the microbes could also be a model for life on Jupiter's ice-covered moon Europa or Saturn's Enceladus. (See "The Hunt for Life Beyond Earth.")

That last bit is the important part--these microbes need neither sunlight nor other organisms for food, only the minerals in the water. This finding increases the probability that similar microbes definitely exist in extraplanetary environments, we simply haven't found them yet.

[Vraith]

That last bit is the important part--these microbes need neither sunlight nor other organisms for food, only the minerals in the water. This finding increases the probability that similar microbes definitely exist in extraplanetary environments, we simply haven't found them yet.

yea. as I'm sure I've mentioned before, I'm as close to 100% certain as doubting-I can be that there is other life out there. I'm nearly that sure that it exists right in our own solar system. We haven't found it, cuz of a mix of can't easily mechanize definitive tests for probes, haven't looked enough places, and can't [yet] send out a multi-site machine to bring back enough samples from likely places so we can do the definitive testing here.

We probably could, with current tech, build a system-covering scooper...but it would be the single most expensive things the world has ever done, and take a really, really long time to do the job.

[SoulBiter]

That last bit is the important part--these microbes need neither sunlight nor other organisms for food, only the minerals in the water. This finding increases the probability that similar microbes definitely exist in extraplanetary environments, we simply haven't found them yet.

yea. as I'm sure I've mentioned before, I'm as close to 100% certain as doubting-I can be that there is other life out there. I'm nearly that sure that it exists right in our own solar system. We haven't found it, cuz of a mix of can't easily mechanize definitive tests for probes, haven't looked enough places, and can't [yet] send out a multi-site machine to bring back enough samples from likely places so we can do the definitive testing here.

We probably could, with current tech, build a system-covering scooper...but it would be the single most expensive things the world has ever done, and take a really, really long time to do the job.

we may even have found it but just didnt recognize it.

[michaelm]

It puts me in mind of something I saw some years ago about the bacteria that exist in the deepest parts of the ocean. If I remember correctly, they exist on the sulfur products that are exuded from rifts in the sea bed.

[I'm Murrin]

It's theorised that those deep sea thermal vents are the very environment in which life on earth first formed. They supply all the necessary elements, and the energy required to turn simple organic* molecules into complex ones. That is in fact why places like Europa and Titan are considered strong candidates for finding life - a certain level of volcanic activity, liquid water, the right elements present.

(There are other theories, of course, particularly since the possibility for formation of complex organic molecules in space was discovered.)



*"Organic" in chemistry refers to almost any molecule containing carbon.

[Vraith]

It puts me in mind of something I saw some years ago about the bacteria that exist in the deepest parts of the ocean. If I remember correctly, they exist on the sulfur products that are exuded from rifts in the sea bed.

And there are microbes in deep rock, that eat various elements and exhale/excrete things like methane or hydrogen sulfide and such.
I think they need a little water, but no oxygen or light.

[TheFallen]

It puts me in mind of something I saw some years ago about the bacteria that exist in the deepest parts of the ocean. If I remember correctly, they exist on the sulfur products that are exuded from rifts in the sea bed.

And it's not just bacteria - although they do form the base of the food-chain there. There are complex life-forms and whole ecosystems around and entirely dependant upon those undersea vents - giant tubeworms for example. I seem to remember that these latter are especially notable for being able to survive quite happily with their head-ends in water of temperatures up to 80 degrees C and their tail ends in water 75 degrees lower.

V and Murrin are entirely correct - basically wherever there's an environment even faintly possible of supporting life, life will apparently spring forth and evolve. In fact, scientists keep having to move the theoretical limits regarding environmental factors forward, because they continually discover life in situations that previous theory would have utterly discounted as impossible. This is making life outside our own little planet look even more likely than ever.

Take a look at this Wiki entry on extremophiles, if you're interested. As Bill Bryson says in my favourite book of all time - yes I had to drag it into the convo again - "life apparently just wants to be".

My personal award for the current extremophile champion, whose very existence goes above and beyond the call of futy, is the bacterium deinococcus radiodurans, which happily munches upon and metabolises such things as highly radioactive substances and heavy metals. It's a polyextremophile that isn't harmed by radiation, extreme cold, dehydration or even acid - scientists are currently investigating it on two main fronts: 1) as a possible "cleaner-upper" of highly toxic or radioactive heavy metal pollution, and 2) in an effort to find out how it so rapidly repairs its own DNA after it has been subjected to chromosome-shredding levels of radiation.

(By the way, the scientific community is at a bit of a loss why D. Radiodurans should have evolved such an ability. It can survive a single acute dose that's 2,000 times stronger than the entire background radiation delivered in a whole year by the most radioactive region known on earth. Or to use another yardstick, it can happily cope with radiation levels 6-25 times those that'd kill "normal" bacteria. It can even tolerate 25% more than those tough little buggers, the tardophiles.)

Other scientists have also postulated that with genetic engineering, deinococcus radiodurans could be used as "living memory storage", in the event of a nuclear or other radioactive catastrophe wiping out most of humanity and the world's knowledge stores. Back in 2003, they actually managed to insert 150 modified base pairs of DNA segments into this hardy bacterium, such base pairs forming an encoding of the song "It's A Small World" (appropriately enough) and then the eggheads retrieved this information uncorrupted 100 bacterial generations later.

Gotta love those forward-thinking boffins...