Bacteria As Fuel Cells?

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."

Comments

They don't produce enough gas for practical use?

[eln]

Have they tried feeding them Taco Bell?

Obligatory Futurama Reference

[rrkap]

Alcohol powered robots can bite my shiny metal ass!

Can someone explain?

[jenny_uk]

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?

Re:Can someone explain?

[mishmash]

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 (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.

Re:Bacteria As Fuel Cells?

[Tackhead]

> Couldn't this be considered somehow as animal cruelty?

Naw, the only thing we've established is that the poster is an invertebrate punster. So slug him!

I am more impressed

[Psionicist]

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 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.

Re:I am more impressed

[Firehed]

But how do you get the bacteria to spin?

I think this is where the alcohol comes into play...

Can you smell the future?

[Itninja]

"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....

Re:Can you smell the future?

[Walt Dismal]

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.

Mutations

[yuckysocks]

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)

pffffft

[MrSquirrel]

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

[mangu]

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?

Bacteria as fuel cells...

[GillBates0]

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 after ingesting healthy amounts of symbiotic bacteria.

Re:They don't produce enough gas for practical use

[God'sDuck]

Yes.

Re:Bacteria As Fuel Cells?

[ChrisGilliard]

Yeah, they better be careful, or PETM (People for the ethical treatment of Monera) might get involved.

Methane vs Hydrogen

[rufty_tufty]

see also:
http://technocrat.net/d/2006/5/23/3693

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...

Make bacteria dependent i.e lac operon, etc

[spineboy]

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.

Keep Quite About It!

[Phat_Tony]

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.

Bacteria Can't Scale?

[Phat_Tony]

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.

At last

[Frightening]

The world has found a use for politicians...

Piss in the gas tank

[yabos]

Now you'll be asking people to piss in your gas tank!