Chemosynthesis

[Mouse]

Can Chemosynthetic organisms create a sustainable oxygen atmosphere in subterranean Mars?

Edited March 15, 2010 by Mouse

[pioneer]

I would have to say no. The reason is, as we increase the concentration of O2, oxidation will compete with the bacteria for the same materials they need for energy to make oxygen.

 

For example, say the bacteria used methane and water, just for the sake of argument. As the O2 builds, we will get methane burn off, lowering the fuel supply and causing O2 to step backwards. With solar energy, we get to build up our energy supply daily, so even if we get reversal due to O2, we never run out of energy supply.

 

The next question is why did the earth's O2 stop at 23%, seeing the reactions can proceed with higher O2 concentrations? With chemosynthetic the value would probably be much lower.

[CharonY]

Which chemosynthetic process generates oxygen?

[ttyo888]

Wait guys, he said subterranean.... Won't the concentration of oxygen be higher if chemo-synthetic organisms are there?

[Moontanman]

Wait guys, he said subterranean.... Won't the concentration of oxygen be higher if chemo-synthetic organisms are there?

 

No, chemo-synthetic organisms almost completely operate in the absence of free oxygen, the ones that do not can and do shift to oxygen metabolism if it is available, and as far as i know and can find out no biological chemo-synthesis would produce oxygen since chemo-synthesis is energy deficient and would not produce a more reactive chemical than it uses.

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Merged post follows:

Consecutive posts merged

 

The next question is why did the earth's O2 stop at 23%, seeing the reactions can proceed with higher O2 concentrations? With chemosynthetic the value would probably be much lower.

 

Actually there is reason to think the Earths atmospheric content of oxygen has been both higher and lower than 21% over the course of complex life.

 

 

http://jeb.biologists.org/cgi/reprint/201/8/1043.pdf

 

Concomitant with this reduction in carbon dioxide

concentration, the oxygen concentration of the late Paleozoic atmosphere may have risen to as high as 35 %

Edited March 16, 2010 by Moontanman
Consecutive posts merged.

[Horza2002]

Atmospheric oxygen levels varied dramatically over the history of life (and indeed the planet). Its widely beleived that in the very early stages of the earth, there was no oxygen present in the atmosphere. The overal levels have vaired dramatically since then. I think the highest levels observed was around 35% (but don't quote me on that, I think I remember hearing that somehwere)

[Mouse]

Oh sorry I thought that Chemosynthesis can like photosynthesis produce oxygen.. Which is the question is how did these producers survive in a place with almost no oxygen.

 

however here's a formula that my friend came up...

 

6CO2(g) + 2Fe2O3(s) + 6H2O(l) ===> C6H12O6(s) + 8O2(g) + 4FeO(s)

 

What do you guys think? This formula might be able to work on MARS...

[CharonY]

There are lots of anaerobic respiration pathways that bacteria used before oxygen emerged.

Edited March 24, 2010 by CharonY

[Mouse]

But most chemosynthetic organism today use oxygen right? If say all of the photosynthetic orgamism die out, will they suffocate?

[Moontanman]

But most chemosynthetic organism today use oxygen right? If say all of the photosynthetic orgamism die out, will they suffocate?

 

No, the vast majority of chemo-synthetic organisms are poisoned by free oxygen and would do quite well if it were to disappear.

[Mouse]

So if a chemosynthetic ecosystem were to be discovered on Mars...

 

One would expect that humans will suffocate there right?

 

I was thinking about the case of Iron bacteria thought, they can turn ferrous oxide into ferrous hydroxide and oxygen.

water + ferric oxide --> ferrous hydroxide + oxygen

[Mr Skeptic]

Can Chemosynthetic organisms create a sustainable oxygen atmosphere in subterranean Mars?

 

A chemosynthetic autotroph in a carbon dioxide atmosphere might be able to do it. However this might depend on there being enough chemicals around for the energy supply; and they would have to be regenerated faster than things like methane in the atmosphere get regenerated. Photosynthesis has and advantage there in that there is plenty of solar energy constantly coming in.

[Mouse]

ferric oxide? Martian soil has plenty of it.

[Moontanman]

It would take energy input to produce oxygen from ferric oxide, where would this energy come from? Photosynthesis uses sunlight to produce carbohydrates, oxygen is a waste product produced in the presence of sunlight, in the dark, plants use oxygen just like animals. Without a surplus of energy how would any martian microbes produce oxygen? Doing so would use more energy than they are getting from the chemicals like an over unity energy machine. For chemo-synthetic microbes energy is already bound up in the chemicals.

[Mouse]

Ok but how do iron bacteria do it?

[Moontanman]

How do they do what?

[Mouse]

Well according to what I found out iron bacteria can turn ferrous oxide into ferrous hydroxide and oxygen.

 

Or is the article I found wrong?

[Moontanman]

Well according to what I found out iron bacteria can turn ferrous oxide into ferrous hydroxide and oxygen.

 

Or is the article I found wrong?

 

Do you have a link to the article?

[Mouse]

http://www.webs.uidaho.edu/gwemo/reports/Iron_Bact_Remediation.pdf

 

http://www.microbiologyprocedure.com/trace-element-nutrition/iron.html

 

http://www.excelwater.com/eng/b2c/iron.php

 

http://en.wikipedia.org/wiki/Iron_bacteria

[Moontanman]

Where concentrations of organic material exceed the concentration of dissolved oxygen required for complete oxidation, microbial populations with specialized enzymes can reduce insoluble ferric oxide in aquifer soils to soluble ferrous hydroxide and use the oxygen released by that change to oxidize some of the remaining organic material:[1]

 

You'll notice this oxygen is not released into the environment but is used by the bacteria to oxidize more organic material, they have to have organic material to start the process, no net free oxygen is produced by these bacteria.

[Mouse]

I see thanks for clearing this up Moontanman.

 

so the result is CO2 instead right?

[Moontanman]

I see thanks for clearing this up Moontanman.

 

so the result is CO2 instead right?

 

If I read the equation correctly the end result is eventually ferric oxide.

[ttyo888]

Hey speaking of which scientists just discovered a bacteria that uses methane to produce oxygen.

 

Moontanman can you verify if this is true? I know that wikipedia has mistakes on the science parts.

 

http://www.nature.com/news/2010/100324/full/news.2010.146.html

[Moontanman]

Hey speaking of which scientists just discovered a bacteria that uses methane to produce oxygen.

 

Moontanman can you verify if this is true? I know that wikipedia has mistakes on the science parts.

 

http://www.nature.com/news/2010/100324/full/news.2010.146.html

 

I think it is misleading to say oxygen is released in the same way photosynthesis releases oxygen, the bacteria actually use nitrogen oxides to produce oxygen it then uses the oxygen to metabolize methane, no free oxygen is produced. This is however an interesting metabolic pathway but some energetic reaction must produce the nitrogen oxides.

 

Many bacteria use oxides of various elements, usually a metal, to produce energy often oxygen is an intermediate part of the reaction but the oxygen is not released as waste like photosynthesis does. Even some metabolic pathways involving photosynthesis do not produce free oxygen. (some release sulfur) There are even metabolic pathways that do not use oxygen as energy at all but actually use sulfur or even hydrogen as an energy source.

 

I think mouse is wanting an underground oxygen atmosphere on Mars due to chemo-synthesis and I doubt this is possible. some sort of photosynthesis using another energy source such as heat or even radioactive particles might be possible in theory but the conditions to allow this are hard to imagine. Some fungi use gamma rays to produce food in a photosynthesis (gamma-synthesis?) process using melanin as a energy gathering pigment.

 

Chemo-synthesis is actually based in the heat energy of the earth released by radioactivity, this excess energy produces chemicals whose energy content is higher than it's ground state and life uses that chemical energy to metabolize. In other words, there is no free lunch.

 

It might be relevant to mention that the surface of mars is thought to contain lots of peroxide chemicals that might be used by life forms, even complex life forms as an energy source, these peroxides are produced by sunlight and might even be used as a body fluid by these life forms since hydrogen peroxides stay liquid at lower temps than pure water.

 

http://www.daviddarling.info/encyclopedia/H/hydrogenperoxide.html#H2O2

Edited March 26, 2010 by Moontanman

[Mouse]

So it will much deeper in the crust where temperatures would be quite warm right? Mars said to have geysers so I think it's going to be pretty warm somewhere.

 

Thanks ttyo888 and moontanman.