Microbes that can generate electricity?

[Lifeson]

I just got my copy of Time today that has an article about the 50 greatest inventions of the year. The one that caught my eye was entitled "The Electric Microbe". According to the article, a microbe known as Geobacter uses pili to generate electricity from mud and waste water. Engineering has been done at the University of Amherst in Massachusetts by Professor Derek Lovley and his team to increase the productivity of Geobacter eightfold. Any more information on this subject will be appreciated as alternative energy is a side interest of mine.

 

Thanks

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Before I forget, Creds for the info:

 

Time, November 23 2009 issue. p 72. Article by Jeffrey Kluger

[Phi for All]

Are these the little guys that can also treat wastewater? I found some related articles here. I wonder if they can find a bacteria that eats nuclear waste and creates power from it?

[CharonY]

There are a number of bacteria, including Shewanella, Geobacter, Anaeromyxobacter just to name some, that at least can reduce uranium (VI) into a less soluble U(IV), which may be more amendable for clean-up strategies. Of course as with other dissimilatory reduction pathways the electron acceptor is not consumed as such, but merely reduced.

 

One problem with microbial fuel cells in general is that in order to create electricity they require (among the usual nutrients) an electron donor. In many cases this is acetate. This, in the end, is rather inefficient as feeding a fuel cell with them would be far too expensive. Using waste, is of course a nice to circumvent the cost problem, but that has some issues, too. One of them is that they already have their particular microflora which are generally not that efficient in generating electricity, but will outcompete those that are. The second is the abysmal efficiency. These are partially the result of energetical limitations of the available biomass.

I think the article also refers to a paper by Lovley in which they isolated (not engineered) a Geobacter strain that was more efficient in fuel cells with acetate (not waste) as electron donor.

In short, a interesting topic, though there are limitations to overall efficiency that are most likely not possible to overcome due to physical constraints. At least not if we think in the direction of large-scale energy production. It is more interesting to think in the direction of bioremediation, though.