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Electrolytic Bacterial Evolution

Stanford researchers gave a peek at some interesting ongoing research at this week's Always On conference. They've discovered a type of soil bacteria that absorbs photons and uses the energy to split water into hydrogen and oxygen. However, the microbe in question is anaerobic, meaning that it will die if exposed to too much oxygen. How, then, could these bacteria ever be used to produce sufficient hydrogen?

This sounds like a job for... Darwin!

To get around this problem, the researchers produce millions of the bugs and expose them to a low concentration of oxygen. They then take the ones that survive and use them to parent a new generation of bugs.

The idea is to, over time, create a new race of bugs that can survive in a relatively normal environment. Entire generations of bugs can be produced fairly rapidly, but wholesale changes in the genetic code do take time.

The research has been going on for about three years, and it's unclear how much longer it will take before they have microbes able to produce hydrogen sustainably.

(Via Sustainability Zone)


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Comments (7)

This helps to pinpoint something I've been trying to fathom over the last few days - can man deal with a constantly evolving world? As well as our cultures being able to use the properties of evolution to our own advantage, can we deal with the changes that might come about gradually in the long term future us bright green types envision? The sharp end of this question centres on microbes and our resistance to bird-flu and suchlike, but I wonder whether we can ever have so much control over our environments that evolution does not throw up curveballs. Situations such as the dependence of modern versions of grain (wheat, barley etc.) on us for propogation will surely arise more and more as we come to dictate our own environments. What implications does this entail?
Sorry, it's slightly off track but I wondered if other people had any thoughts on the issue.

Good heavens, didn't these people ever consider that there are millions of years' worth of evolution making these microbes live in an anaerobic environment? They think they're smarter than that?

Hubris - the great equalizer.

Well, yes, they are smarter than evolution. Evolution is a "dumb" process -- there's no direction to it, it's simply responsive to changes in the environment. It quite often leads to dead ends and overspecializations and myriad examples of organisms well suited to a particular time and place and unable to survive change.

These researchers aren't altering the entire species; the result is likely to be unable to survive well outside of specialized "habitats" in laboratories.

And, Daniel, the question of how we deal with an evolving environment is a very good one.

the labrat:

call me naive, but couldn't you just do something like have the process occur in solution under enough of a vacuum pressure that the dissolved oxygen would bubble out of solution quicker than the concentration could build up enough to kill the bacteria? admittedly, i don't have a general chemistry or biology textbook on hand and haven't given more than a quick minute's thought to this, but instead of messing with the bacteria wouldn't it be easier to just get rid of the oxygen more quickly? or maybe you could achieve some kind of symbiotic system with an oxy-philic bacteria (algae?) that would consume the oxygen as quickly as it was produced?

Jamais, one doesn't have to assume a God, an "Intelligent Designer" or other teleological force to know that evolution is not "dumb". Any cybernetic process with powerful feedback loops, acting upon countless generations for eons, with multiple fitness tests, linked together in ways we're only beginning to imagine, is not easily bested by our efforts in a laboratory.

Evolution, as we understand it, should inspire reverence, not hubris.

That said, your point's well taken: this is not unlike domesticating farm animals or plants, maintaining a sourdough culture or finding an excellent wine yeast. I just hope that research like this is done mindfully.


To the_labrat:
I like the idea of having these particular bacteria cocultured with bacteria that could consume the oxygen in the system in order to keep the levels down, though they would probably still have to have a certain level of tolerance to prevent the culture from dying horribly under small perturbations of the conditions.
While a vacuum is a nice idea, it doesn't work for one very simple reason -- bacteria + vacuum = exploded bacteria.

There seems to be a certain discussion going on here about evolution being "smart" or not. In my opinion, this stems from the larger problem of the two definitions of "evolution" that are currently floating around: telelogical evolution (evolution with a clear purpose, evolving towards something, which seems to be the popular definition at present), and what could be called "dumb" evolution (or what I sometimes think of as "strict" evolution).

While popular culture seems to have latched onto the idea of teleological evolution, there is no evidence that evolution has any sort of intent or direction to it. It is a very refined system, and quite elegant, but it does not have some sort of final goal. If it did, there probably would have been some sort of irreversible mis-step along the way due to a miscalculation of future conditions, and life on earth might have just died out. We are not the X-Men; there is not a "next step" in human evolution, or any evolution for that matter.

It is not likely that these bacteria evolved "to be" anaerobic. Oxygen is a relatively reactive compound and oxidation is one of the major difficulties that aerobic cells have to deal with. Since the early atmosphere was anaerobic, the earliest bacteria were anaerobic and did not have mechanisms to deal with oxygen; that would take extra energy and was at the time unnecessary. As concentrations of oxygen in the atmosphere increased after photosynthetic bacteria evolved, there were three options for the organisms that were there at the time, (1) be in an inhabitable anaerobic niche (e.g. deep sea, deep soil, etc), (2) get lucky and have a mutation that conferred oxygen tolerance, or (3) die.

These bacteria are likely from the first category, though they may be descendents of the second category that lost their oxygen tolerance upon settling into an anaerobic niche (in the same manner as humans have lost our ability to synthesize vitamin C after a long period of subsisting on a diet relatively rich in vitamin C; we didn't need it, so those that lost it had an energetic advantage and that energy ended up redirected to other pursuits more helpful for survival). Evolution did not "intend" for them to be anaerobic, that's simply the way they ended up. Therefore, it is possible that with concerted artificial selection, these bacteria may be domesticated to be tolerant of oxygen while maintaining their ability to split water.

It is quite possible that their may be some significant genetic stumbling blocks that would make this project difficult to impossible, such as strong linkages between the genes that would have to be modified to confer oxygen resistance and the genes that confer efficient water-splitting, but it is also possible that through concerted efforts, the appropriate mutations will surface. Care must be taken to make sure these bacteria won't survive outside the lab; the global warming that would probably if they were well-suited to open-ocean life would be less than ideal. Still, I think it is a path worth pursuing. If we can make fuel-cell technology more energy-efficient than gasoline my making hydrogen production more energy-efficient, it will be a giant leap in the right direction.


what is the irrefutable scientific proof for dumb (strict) evolution over other evolutionary theories? (ie along the lines of absence of proof doesn't equal proof of absence)?


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