Moontanman Posted October 5, 2018 Share Posted October 5, 2018 More organisms living deep in the earth by metabolizing hydrogen. Cyanobacteria show up in yet another odd place! Just ad them and stir to create an earth like environment! https://www.space.com/42001-weird-underground-microbes-aid-mars-life-search.html 1 Link to comment Share on other sites More sharing options...
MigL Posted October 5, 2018 Share Posted October 5, 2018 I've often wondered why no-one has tried to introduce cyanobacteria, not to Mars, but to Venus. A small amount, to see if they can survive, even as an experiment on Earth.. Then, after the introduction to Venus, evolve and start changing the atmospheric composition. Who knows, in a couple of million years, Venus might resemble an Edgar Rice Burrows novel 1 Link to comment Share on other sites More sharing options...
Silvestru Posted October 5, 2018 Share Posted October 5, 2018 https://en.wikipedia.org/wiki/Interplanetary_contamination You really have to research every scenario. We might end up ruining a great opportunity by introducing the wrong microbes. I think there are too many unknowns in this field to just introduce some microbes and wait to see what happens. Quote Introduced Earth life could contaminate resources of value for future human missions, such as water. https://en.wikipedia.org/wiki/Planetary_protection Link to comment Share on other sites More sharing options...
Kelli9 Posted October 29, 2018 Share Posted October 29, 2018 (edited) On 10/5/2018 at 8:24 AM, MigL said: I've often wondered why no-one has tried to introduce cyanobacteria, not to Mars, but to Venus. A small amount, to see if they can survive, even as an experiment on Earth.. Then, after the introduction to Venus, evolve and start changing the atmospheric composition. Who knows, in a couple of million years, Venus might resemble an Edgar Rice Burrows novel But, no one has even been to mars or Venus yet... So how could someone have tried by now? Edited October 29, 2018 by Kelli9 Link to comment Share on other sites More sharing options...
swansont Posted October 29, 2018 Share Posted October 29, 2018 4 hours ago, Kelli9 said: But, no one has even been to mars or Venus yet... So how could someone have tried by now? We have robots on Mars, and have sent probes to Venus. One of the concerns of the Mars missions was that they would bring earth microbes with them, and corrupt the planet. Link to comment Share on other sites More sharing options...
CharonY Posted October 29, 2018 Share Posted October 29, 2018 (edited) On 10/4/2018 at 8:39 PM, Moontanman said: More organisms living deep in the earth by metabolizing hydrogen. Cyanobacteria show up in yet another odd place! Just ad them and stir to create an earth like environment! https://www.space.com/42001-weird-underground-microbes-aid-mars-life-search.html I would need to see the original paper, but I am not quite sure what the new bit here is. There are plenty of anaerobic bacteria that utilize hydrogen as electron donor. And there were papers back in the 70s who described the use of hydrogen as donor in a PSI-dependent reaction. Perhaps there are new details emerging, but at least from the linked article it is not quite clear what the really new finding is (perhaps the isolation area is different, but then those buggers are pretty much everywhere). Edited October 29, 2018 by CharonY 1 Link to comment Share on other sites More sharing options...
Moontanman Posted October 29, 2018 Author Share Posted October 29, 2018 Hydrogen "breathing" microbes... how far from a complex life form endosymbiosis with these bacteria would allow for complex organisms physically to physically breath hydrogen much like mitochondria allow complex life to breath oxygen? I am thinking of a super earth type planet with maybe a 10 bar hydrogen atmosphere over a rocky planet with oceans. I know a complex life form here on earth has buddied up with an anaerobic bacteria to live in anaerobic environments. https://en.wikipedia.org/wiki/Hydrogenosome Link to comment Share on other sites More sharing options...
CharonY Posted October 29, 2018 Share Posted October 29, 2018 17 minutes ago, Moontanman said: Hydrogen "breathing" microbes... how far from a complex life form endosymbiosis with these bacteria would allow for complex organisms physically to physically breath hydrogen much like mitochondria allow complex life to breath oxygen? So with using the term "respiration" you will have to be careful whether you think of hydrogen as electron donor (the role otherwise played e.g. by glucose ) or the terminal acceptor (the role played by oxygen). Due to the low redox potential, the latter generally does not allow the generation of energy and is mostly involved in energy conservation and to balance reducing equivalents in fermentative processes. Hydrogenomsomes are example of such processes as the reduction of H+ to hydrogen does not yield energy per se, but rather regenerates ferredoxins. With regard to the first role, i.e. oxidation of hydrogen, there are examples of endosymbionts of tube worms, I believe, and probably more critters around hydrogen vents. I am not sure how much or if these symbionts contribute to the energy balance of the host or whether they perhaps only contribute to nutrition. These are not necessarily anaerobic per se, as it would possible to couple hydrogen oxidation to oxygen as electron acceptor. Link to comment Share on other sites More sharing options...
Moontanman Posted October 30, 2018 Author Share Posted October 30, 2018 2 hours ago, CharonY said: So with using the term "respiration" you will have to be careful whether you think of hydrogen as electron donor (the role otherwise played e.g. by glucose ) or the terminal acceptor (the role played by oxygen). Due to the low redox potential, the latter generally does not allow the generation of energy and is mostly involved in energy conservation and to balance reducing equivalents in fermentative processes. Hydrogenomsomes are example of such processes as the reduction of H+ to hydrogen does not yield energy per se, but rather regenerates ferredoxins. With regard to the first role, i.e. oxidation of hydrogen, there are examples of endosymbionts of tube worms, I believe, and probably more critters around hydrogen vents. I am not sure how much or if these symbionts contribute to the energy balance of the host or whether they perhaps only contribute to nutrition. These are not necessarily anaerobic per se, as it would possible to couple hydrogen oxidation to oxygen as electron acceptor. Would the partial pressure of gasses play into the energy released? A lung full of our atmosphere contains considerably fewer oxygen atoms than a 10 bar hydrogen atmosphere contains hydrogen atoms in the same volume. Also hydrogen diffuses into tissue much easier than oxygen.. Link to comment Share on other sites More sharing options...
CharonY Posted October 30, 2018 Share Posted October 30, 2018 (edited) 1 hour ago, Moontanman said: Would the partial pressure of gasses play into the energy released? A lung full of our atmosphere contains considerably fewer oxygen atoms than a 10 bar hydrogen atmosphere contains hydrogen atoms in the same volume. Also hydrogen diffuses into tissue much easier than oxygen.. Not really. The limiting factor is the redox potential between terminal acceptor and donor. The potential energy does not change. Think of it that way. The energy you could obtain from dropping a single weight from 100 ft does not change whether you used one or two ladders to get there. Also think in terms of potential as the height. I.e. if you start with glucose and end with oxygen, you are much higher than if you started e.g. with lactate instead of glucose. Or if you ended with nitrate instead of oxygen. With hydrogen as an acceptor you have the even bigger issue that redox potential is at a level where respiration actually normally starts. I.e. think of hydrogen being basically the same height as the floor. Dropping anything from there will give no or negligible energy. Edited October 30, 2018 by CharonY 1 Link to comment Share on other sites More sharing options...
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