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

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?

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

[ceoyoyo]

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 get the bacteria to spin?

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)

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?

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...

Re:Bacteria Can't Scale?

[megalobrainiac]

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.