Microbes that make their own water- implications for solar system life?

[marsbug]

This article(with a link to the paper it's based on that I can't acess) on the arXiv physics blog mentions that there is evidence suggesting some microbes can manufacture water from hydrocarbons. If this is confirmed it suggests a new paradigm for the search for alien microbes: 'follow the organic chemistry and energy disequilibrium', not 'follow the water' would be the new motto.

How would our prioritizing of targets change if it turns out life does not need pre-existing water, only appropriate materials to make it?

And would anyone with chemistry background care to guess how wide the range of appropriate materials might be?

[Canis Lupus]

The article suggests it is not clear whether the organisms are water dependent or not - more study is needed. Or looked at another way, the organisms are still water dependant except they are able to produce their own. Clever.

...there is also evidence that liquid water may not be as important as everybody has assumed. Schulze-Makuch and co point to recent evidence that some microorganisms can make there own water by chewing on various hydrocarbons. However it is not yet clear how much water the bugs in Pitch Lake require. Although there is very little water here, it's just possible that the organisms are confined to regions where the water content is higher...

The organisms which are the direct subject of the article are not the ones which are said there is evidence they are producing their own water - a statement which is hardly conclusive in regard to the ones which are subject to the comment, incidentally. Nonetheless, such organisms are important in both the context of the possibility of life on Titan or even seeding life on Titan with the very same type of organisms. The same applies in a wider context, I believe, because there are growing indications that life generally on earth is capable of the most remarkable adaptations. Again, it gives hope, as your post suggests Marsbug, for more diverse habitats on a stellar level. From my hobby horse's point of view, greater strength to the idea of directed panspermia in the event that places like Titan and others are discovered not to have life.

As an aside, shouldn't it be "their own water" rather than "there own water". I'm not 100% sure on this one because of the "own". Tricky.

[Strange]

As an aside, shouldn't it be "their own water" rather than "there own water". I'm not 100% sure on this one because of the "own". Tricky.

It should be "their". The quality of the writing is appalling: Trinidad and Tobago are two sperate islands, bacteria as "creepy crawlies"? "munching on hydrocarbons"??

Water will always be a byproduct of metabolism. Whether they produce enough for their needs is interesting. Although they will, presumably, have evolved from bacteria in a more aqueous environment.

[Canis Lupus]

"munching on hydrocarbons"??

It may not be terribly scientific, but it does have a nice ring to it. I can just hear mother micro-organism nagging her off-spring, "Now eat up all your hydrocarbons".

[marsbug]

Well I did try to cover my rear by saying 'if this is confirmed'. And in the quote you posted the pitch lake bugs are referred to immediately after the 'make their own water by chewing hydrocarbons'so I've assumed the researchers are thinking that the pitch lake bugs might also be making their own water. Edit; as canis lupus points out, there is no direct evidence of the pitch lake bugs making their own water, other than that they (possibly) survive where there is no naturally occuring water. end edit.

And yes whoever wrote that article needs an editor. There're mistakes like that all through it. But then again maybe the microbes have a water co-operative system where no-one can claim ownership of the water they make?

I assume the actual paper does a bit better on that score, can anyone acess it?

I think the idea of microbes that make their own water improves the chances of life in places like the venusian clouds, where the environment is chemically complex and in disequlibrium, but actuall H2O is scarce. If it turns out to be true then the idea of life in the clouds of venus looks a bit more promising, although the process there would have to use sulphur based compounds I suspect.

It makes sense to me though, I've read of microbes making almost everything they need to live from raw materials, it's never made sense to me that water would be an exception.

Edit; and as strange points out, it's a by product of metabolism anyway.

My next question would be; If this is true, has our strategy of looking for the water ed us to less than optimal hunting grounds for life? End edit.

[centsworth_II]

I assume the actual paper does a bit better on that score, can anyone acess it?

http://arxiv.org/ftp/arxiv/papers/1004/1004.2047.pdf
You can get to it from the site linked in the article.

[marsbug]

Thanks Centsworth. Following the references in that paper back a stage brought me to this paper: http://www.pnas.org/content/102/48/17337.full

I'll quote the conclusion:

The data presented here indicate that a substantial fraction of intracellular water extracted from log-phase E. coli cell cakes produced in 2× LB is metabolic water. At this growth stage, ≈70% of the intracellular water is generated via metabolism, and two different approaches independently estimate that the δ18O value of the metabolic water is approximately –3.5‰. Intracellular water from stationary-phase and quiescent cells showed a substantially smaller contribution from metabolism.

So it seems it is possible for microbes to generate most of their internal water, at least when their metabolisms are running high. It's not a very big leap from there to microbes that can generate all their internal water.

Is naturally occuring liquid water really a prerequisite for life to survive? It might still be needed for life to start, but thereafter perhaps chemical disequilibrium and abundant carbon become more important.

Edit: canis lupus; detection is the problem, especially if the only real sources of energy are underground. However there might still be detecable traces at the surface.

Still there is world much closer than titan with abundant energy, earth like temperatures and pressures, all accessable (70km)above the surface; Venus.

I've read something about microbes being found alive and respiring in earths cloud deck, I'll see if I can find it again.

Psst, NASA, not mars, venus, VENUS! Not that I have an opinion I'd like to air or anything.......
Any other suggestions, if it turns out water is just another compound microbes can make for themselves?

[Nick Theodorakis]

Thanks Centsworth. Following the references in that paper back a stage brought me to this paper: http://www.pnas.org/content/102/48/17337.full

I'll quote the conclusion:


So it seems it is possible for microbes to generate most of their internal water, at least when their metabolisms are running high. It's not a very big leap from there to microbes that can generate all their internal water.

Is naturally occuring liquid water really a prerequisite for life to survive? It might still be needed for life to start, but thereafter perhaps chemical disequilibrium and abundant carbon become more important.

This seems to be a matter of recycling water rather than making new water. Water is made during synthesis of macromolecules (which are condensation reactions) but is split during hydrolysis of them (which is why it's called hydrolysis). We might be just determining the rate of water recycling is faster than the diffusion or transport of water across the cell membrane.

One caveat to this study is that they are using a hyperosmolaric medium (roughly twice the salt concentration typically used for these bugs). I wonder if these conditions favor the retention of water within the cell and thus would amplify the role of water recycling.

Nick

[marsbug]

'Kay I bow to superior expertise in cell biology. Do I understand correctly that by recycling you mean the water is made in the cell in one set of reactions, and then split in another? So the cell is making water, and then destroying it?

Edit: The point I'm confused on is; earlier in the thread someone said that water was a product of metabolism. Is that correct, or is water used in metabolism, and then recycled sometimes?

[centsworth_II]

The bacteria in this case may be making water from biologically produced organic compounds, but it suggests the intriguing possibility of organisms making water from non-biological compounds containing hydrogen and oxygen.

[ravens_cry]

I can make water from hydrocarbons too, I burn 'em. You know that dribble from your exhaust pipe on a cold day when your idling? That there is condensing water vapour from your exhaust.

[marsbug]

Thats what I was thinking. But then why wouldn't it be assumed that cells could supply at least some of their own water via their food? And again, from there I don't find it a great leap to a cell that can get all the water it needs from it's food. So I'm wondering if I've missed something important, I did have to re-read Nicks post to be sure I'd understood it!

[Canis Lupus]

I can make water from hydrocarbons too, I burn 'em. You know that dribble from your exhaust pipe on a cold day when your idling? That there is condensing water vapour from your exhaust.

We can send you to Titan.

[ravens_cry]

We can send you to Titan.

Be sure to send along some free oxygen, please?

[marsbug]

Thr 'rock' on titan is mostly water..... you'lljust have to hold your breath and rub your arms until you can get a hydrolisis plant set up. Then you can start a fire and you'll be fine!

[marsbug]

The wikipedea article on metabolic water mentions species, complex multicellular species, that rely solely on metabolic water for long periods of time. Hell, it says I'm 10% metabolic water. Now I'm really confused, whats the 'news' here, that life can survive off water from metabolism alone, that single cell creatures might be able to, or that single cell creatures might be able to using inorganic sources to produce water as centsworth says?

Or is this no news at all,and some people (me for one) just haven't heard of this before?

[Boratssister]

Mmm may be all the water in the universe was made by life? Wouldn't that be a turn up for the books!

[Nick Theodorakis]

We can send you to Titan.

Be sure to send along some free oxygen, please?

Oxygen plus loads of hydrocarbons = ... well, I wouldn't light a match.

Nick

[ravens_cry]

Oxygen plus loads of hydrocarbons = ... well, I wouldn't light a match.

Nick

Actually, that's the idea. Burning a hydrocarbon in oxygen results in dihydrgen monoxide and carbon dioxide, producing water from hydrocarbons. Also, if your sending me to Titan, I *ahem* want some for my own oxydative needs.

[Canis Lupus]

I had forgotten Titan's surface was mostly rock hard ice. What energy sources, if any, might be available on Titan? Obviously solar energy is probably not an option. Is there evidence of strong winds for example?

Also, what primary difficulties would a manned probe face in walking on the surface?

Obviously Ravens_cry will need more than his out of tune car up there.

[Drunk Vegan]

What implications might this have for space colonization? Could these organisms, in great numbers and spread over a large area, actually produce enough water to matter for the purposes of a colony, or even terraforming?

[Canis Lupus]

What implications might this have for space colonization? Could these organisms, in great numbers and spread over a large area, actually produce enough water to matter for the purposes of a colony, or even terraforming?

The primary problem with Titan is its temperature. Unless there are places on it which allow for water it is hard to imagine any micro-organisms reproducing, unless the organisms themselves can invoke a chemical reaction producing heat or we artificially introduce one. This is why Europa is perceived as a better hope for life with the idea that the surface is ice and the cracking on the surface is caused by a subterranean heat source, which potentially may cause melting of deeper levels of ice with resultant water.

If everything goes true to form, Europa will surprise us with something quite different, once again showing us how little we understand, mocking all our best thought out theories. I'm reminded very much of what we originally expected to find on the moons of Saturn and Jupiter prior to any probes - just rocky balls like ours they thought. hehe haha.

[ravens_cry]

I had forgotten Titan's surface was mostly rock hard ice. What energy sources, if any, might be available on Titan? Obviously solar energy is probably not an option. Is there evidence of strong winds for example?

Also, what primary difficulties would a manned probe face in walking on the surface?

Obviously Ravens_cry will need more than his out of tune car up there.

Ironically, it may be wise to include a vacuum layer, like a Thermos, to keep heat from leaking out into the cryogenic atmosphere,as a vacuum is an excellent insulator.

[mugaliens]

I can just hear mother micro-organism nagging her off-spring, "Now eat up all your hydrocarbons".

So they're members of the "clean tar-pit club?"

[neilzero]

To make water from hydrocarbons a source of oxygen is needed, and most oxygen compounds seem unlikely. Typically a lot of energy is required to free the oxygen from the compound, so it can combine with the hydrogen in the hydrocarbon. Neil