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Bacteria As Fuel Cells?

Posted by ScuttleMonkey on Wed May 24, 2006 05:26 PM
from the lazy-bacteria-just-needs-training dept.
KantIsDead writes "MIT's Tech Review is running an interview with Boston University Bioengineer Tim Gardner about the possibility of using bacteria to produce electricity. If fuel cells running off sugar are nearly here, alcohol-powered robots cannot be far." From the article: "While typical fuel cells use hydrogen as fuel, separating out electrons to create electricity, bacteria can use a wide variety of nutrients as fuel. Some species, such as Shewanella oneidensis and Rhodoferax ferrireducens, turn these nutrients directly into electrons. Indeed, scientists have already created experimental microbial fuel cells that can run off glucose and sewage. Although these microscopic organisms are remarkably efficient at producing energy, they don't make enough of it for practical applications."
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  • Have they tried feeding them Taco Bell?
  • by rrkap (634128) on Wednesday May 24 2006, @05:31PM (#15397885) Homepage
    Alcohol powered robots can bite my shiny metal ass!
  • Couldn't this be considered somehow as animal cruelty?
  • Can someone explain? (Score:3, Interesting)

    by jenny_uk (976951) on Wednesday May 24 2006, @05:32PM (#15397890)
    How exactly do you take full atomic structures and "turn these nutrients directly into electrons"? Even if you were able to release the electrons from the atoms the whole material remains, neutrally charged does it not?
    • by mishmash (585101) on Wednesday May 24 2006, @06:01PM (#15398038) Homepage

      Take glucose - perhaps produced by a bacteria, or as also mentioned in the article available in the human blood stream and using a glucose oxidase enzyme - oxidise it - take electrons from it, you do this on the surface of an electrode at one end of the circuit - at the other end you have another electrode coated with another enzyme on that uses electrons to reduce someting - such as oxygen to water. With oxidation at one end and reduction at the other you have electrons flowing between them.

      A paper describing doing this - but not using real human blood [acs.org] (why doesn't someone get on and do that - has the human race lost the spirit of development??)

      Why use bacteria and not just enzymes? One answer maybe that enzymes need a specific substrate, some bacteria might be less choosey? An enzyme's only a catalyst why not use "chemical" catalysts like conventional fuel cells?

      As for the biology major's worry that bacteria will lose the genetic modifications over time - yes that will happen - as the modifications that make them better for the purpose of making electricity will make them less good at simply multiplying - so loosing the extra function will give them an advantage which will be naturally selected for - so those bacteria will take over the culture. The solution's - you'll just not grow these things indefinatly - you'll have get a fresh culture of them regularly.
    • Well, your body and that of every other living thing on the planet does it all the time. These bacteria just manage to spit the extra electrons out so we can use them for our nefarious purposes.
  • I am more impressed (Score:5, Interesting)

    by Psionicist (561330) on Wednesday May 24 2006, @05:34PM (#15397898)

    I am more impressed with that Montreal kid who did something similiar:

    http://www.wired.com/news/technology/0,70882-0.htm l?tw=wn_index_12 [wired.com] A 16-year-old high school student has invented a new way of producing electricity by harnessing the brawny power of bacteria.

    Kartik Madiraju, an 11th-grader from Montreal, was able to generate about half the voltage of a normal AA battery with a fifth of an ounce of naturally occurring magnetic bacteria. And the bacteria kept pumping current for 48 hours nonstop.
    • I read that article and it seems kind of shady... they're saying he's invented a clean source of energy but it sounds more like he made a very inefficient generator. Basically the bacteria are like little magnets so if you make them spin they'll produce a spinning magnetic field. If you then let the field lines cut through a coil a current will be generated. Which is exactly like a generator except using magnetic material surrounded by bacteria instead of just straight magnetic material.

      But how do you ge
  • by Itninja (937614) on Wednesday May 24 2006, @05:37PM (#15397911) Homepage
    "alcohol-powered"
    "glucose and sewage"

    The future will be full of cars that only exaust water....and fueling stations brimming with switch-grass, corn-mash, stale beer, human feces, and the occasional Rhodoferax ferrireducens bateria. And I thought horses smelled bad....
    • by Walt Dismal (534799) on Wednesday May 24 2006, @06:14PM (#15398117)
      I'm planning to create cars that run on armpit bacteria. See, then taxicabs in New York City could run forever without a fill-up.
    • >The future will be full of cars that only exaust water....and fueling stations
      >brimming with switch-grass, corn-mash, stale beer, human feces, and the
      > occasional Rhodoferax ferrireducens bateria

            The future? Obviously, you have never been in a typical Tennessee gas station...

                Brett
  • Mutations (Score:5, Interesting)

    by yuckysocks (806608) on Wednesday May 24 2006, @05:38PM (#15397923) Homepage Journal
    Ok, assume that in 3 years we find just the right bacteria we need, and can have big
    enough colonies of them to be useful. How do we stop them from just mutating into
    non-viable types of their former selves and corrupting the colony? Sure they would
    reproduce asexually and that would limit mutations compared to our dirty process
    with gametes and zygotes, but that small rate of mutation will definitely be amplified
    by the apparent fact that we'll need trillions of these bacteria to do anything large-scale.

    IAABM (I am a biology major)
    • Sure they would reproduce asexually and that would limit mutations compared to our dirty process
      with gametes and zygotes,


            Bacteria can reproduce sexually as well. There's no stopping the horny little bastards.

            If you provide an constant, optimum climate for your strain, however, there wouldn't be a great deal of evolutionary pressure forcing them to mutate into non-viable types.
      • I *think* he meant non-viable in terms of not being useful at generating fuel, not non-viable as in "not going to survive".

        For example, consider a mutation that was better at reproducing but not at all good at generating us electricity/fuel/whatever. It could rapidly "corrupt" the population.

      • If you provide an constant, optimum climate for your strain, however, there wouldn't be a great deal of evolutionary pressure forcing them to mutate into non-viable types.

        I'm not sure this is a good assumption. If the bacteria were a product of genetic engineering and not selective breeding in that environment, they might be easily overwhelmed by a mutant strain that was more suited to the environment, but less useful to us. For example, we might engineer bacteria that produce electricity, but do it at the
    • I think what you'd want to do is probably have a supply of preserved "first generation" (or "zero generation") bacteria, and every once in a while sterilize the production tanks, kill off all the mutant bugs that have bred there over the interim period, and re-stock it with fresh stuff.

      Or just use a fresh starter of bacteria for each batch. That's basically what bakers do today with yeasts: in the past, a good bakery would have had a 'starter' filled with yeast, which they'd put a small piece of into each b
    • I would just split the colony into many smaller isolated colonies. If one becomes corrupted just throw it out and start over from another, non-corrupted, source.
    • by spineboy (22918) on Wednesday May 24 2006, @06:06PM (#15398076) Journal
      Make the bacteria dependent on an added compound that is associated with the genes you want to keep. Use the lac operon as an example - add lactate and the gene switches on, but in our bacteria, it turns on a gene cascade that produces the enzymes that give us EtOH/electricity as well as another product that the bacteria needs to survive. If the bacteria kicks out the desired gene that we want, it also kicks out the compound that regulates its cell cycle, and it dies.

      It would be unlikely for the bacteria to spontaneously mutate out 2 genes at once, thereby subverting our design. Obviously bacteria, number in the billions, so it will be necessary to restock our fuel cell occasionally. Of course you could be clever and tie in a third gene that gives immunity to a toxic substance, so that non-desired mutated bacteria are killed off automatically.

    • Have more than one tank, evaluate the takes for stability, power production, and any other facters you like. Then kill off the problem tanks and restart them with the best tanks. Over time things will just keep getting better.
    • Re:Mutations (Score:3, Insightful)

      What stops cows from mutating into something less optimal for humans?

      When (not if) it happens, we kill the results and don't let them breed.

      Why do you think it'll be any different with the bacteria? It's not as if all the bacteria in the world will be in one tank in one gigantic, completely inseperable pile.
      • Human beings control the mating stock. They choose the bulls that they want, and this keeps things under human control. You can't do that with bacteria. The idea of putting other important genes (resistance, etc) close to the 'on' switch for production is the best solution I've heard so far. It makes it that much harder to get rid of the crucial gene. But not impossible. You might still need a yearly cleaning.
  • pffffft (Score:3, Funny)

    by MrSquirrel (976630) on Wednesday May 24 2006, @05:39PM (#15397931)
    I invented this concept years ago. Step 1: Get my feet really worked up and sweaty while trapped in a tight shoe -- this spurs bacterial growth Step 2: Take off shoe and attack roommate with it -- roommate runs away from the stink, but he is roped onto a treadmill Step 3: The kinetic energy from the treadmill's movement is converted into electrical energy. I've just been working on creating a pocket sized roommate/treadmill, I was pretty darn close too.
  • Medical implants (Score:5, Interesting)

    by mangu (126918) on Wednesday May 24 2006, @05:40PM (#15397933)
    TFA mentions powering medical implants as a possibility. Now, before anyone puts a bacteria powered implant inside me, I would like the answers to two questions:


    1) What if the bacteria escape from the implant and spread through my body?


    2) Could an antibiotic cure for an unrelated infection kill my artificial heart?

    • The answer to 1 is simple: you would turn into ... ELECTRIC MAN!!!
    • 1) What if the bacteria escape from the implant and spread through my body?

      Your immune system deals with them. If they're not optimized to reproduce in that environment, there wouldn't even be much risk of "spread". Not all bacterias thrive in the human body, after all.

      2) Could an antibiotic cure for an unrelated infection kill my artificial heart?

      Presumably your artificial heart's bacterial power source would not be exposed to your body, any more than today's artifical hearts press their battery leads rig
    • Even better. Think Big.

      Think of an implant that burns glucose in the blood and either remotely powers gadgets or keeps you extra warm. Just the burning calories part will make people rich. How about breast implants that will burn your calories for you to produce extra body heat?

      • That'd be great for people with diabetes too. Why can't they do somthing as simple as remove glucose from the bloodstream and burn calories. Heck, even if you have to raise someone's temperature a degree, it's better than glaucoma.
  • by GillBates0 (664202) on Wednesday May 24 2006, @05:40PM (#15397936) Homepage Journal
    If fuel cells running off sugar are nearly here, alcohol-powered robots cannot be far.

    Neither can power plugs that you can directly plug into your ass [wikipedia.org] after ingesting healthy amounts of symbiotic bacteria.

  • It is only a short time before Bender Bending Rodriguez is made in some Mexican factory.

    (I am Bender. Please insert beer.)
  • Methane vs Hydrogen (Score:5, Interesting)

    by rufty_tufty (888596) on Wednesday May 24 2006, @05:57PM (#15398018)
    see also:
    http://technocrat.net/d/2006/5/23/3693 [technocrat.net]

    bacteria + rotting biomass has long been able to produce energy.
    I can see this is new because it produces hydrogen as opposed to other gasses, but is a hydrogen economy that much better than a methane economy if it is based on biomass?
    Maybe in 50 years time?

    Ok I'll mod myself Troll now...
  • <<
    alcohol-powered robots cannot be far.
    >>

    I'm back, baby ! My friends and I were just in this bar, right around the corner !
    -- Bender

  • by Phat_Tony (661117) on Wednesday May 24 2006, @06:31PM (#15398198) Homepage
    Ssshhhh!!!

    No one tell the computers, or they won't have any reason to keep us alive after they take over.

    Plus the bacteria won't need an elaborate VR to keep them occupied while generating electricity.

  • by Phat_Tony (661117) on Wednesday May 24 2006, @06:47PM (#15398265) Homepage
    Although these microscopic organisms are remarkably efficient at producing energy, they don't make enough of it

    There's something wrong with this sentence. It sounds like they're saying that the bacteria perform an efficient conversion of the sugar energy into electrical energy, but that the problem is that bacteria can't be scaled effectively to produce significant amounts of power.

    There's a problem with the idea that bacteria don't scale. Bacteria are well known for their exponential growth curves. Give me a sufficently large petri dish with medium and a starter batch of bacteria, and I'll solve your scaling dilemma.

    If they are truly efficient, then there's no problem with bacteria not making enough power, as making more bacteria is trivial. However, I don't think it's likely they really are efficient. It seems highly unlikely bacteria would waste much energy on producing unused electricity, one might expect them, like most living things, to use most of their available energy growing, respirating, reproducing, and anything else that generally falls under the category of "surviving." Sure enough, later in the article comes:

    Gardner's team aims to harness the genetic control system to engineer bacteria that can produce energy more efficiently.

    Which makes me think that the problem with the current bacteria is efficiency, not scalability, as the first sentence implies. Perhaps by "efficient" he means that they don't produce a lot of waste heat or something, but for generating electricity, the definition of efficiency should be what percent of the energy they take in they put back out as electricity.

    • Some undergraduates I know who were working in Tim (Gardner, the guy in the article)'s lab pointed out that their little tabletop fuel cell powered by bacteria did work, but produced
      _microwatts_ of power.

      Tim's great (he gave an impassioned sermon on 'The End of Oil'... in his nonlinear dynamics class!) and he's in it for the long haul, but they're not there yet.

  • At last (Score:4, Funny)

    by Frightening (976489) on Wednesday May 24 2006, @07:10PM (#15398343) Homepage
    The world has found a use for politicians...
  • by yabos (719499) on Wednesday May 24 2006, @07:29PM (#15398417)
    Now you'll be asking people to piss in your gas tank!
  • by PSaltyDS (467134) on Wednesday May 24 2006, @07:32PM (#15398426) Journal
    "...alcohol-powered robots cannot be far."

    Some of them work in the cubicle next to mine...

  • A lot of good microbial fuel cell work, including the discovery of the geobacter genus, has been done by D.R. Lovley and the group at UMass/Amherst [geobacter.org].

    In addition to their work on the microbial fuel cells [geobacter.org] themselves, they've also made the interesting discovery that the bacteria naturally form nanowires [geobacter.org] to transfer electrons outside the cell--something potentially [sorry!] useful to connect to an external electrode.
  • Bacteria.... Hell, in my neck of town we just use water!

    Water Fuel Cell [waterfuelcell.org]