IRON EATING BACTERIA CAN EAT ELECTRICITY INSTEAD

         

         Scientist have developed a way to grow iron oxidizing bacteria using electricity instead of iron, an advance that will allow them to better study the organism and could one day be used to turn electricity into fuel. The study will be published in mBio.


         The method, called electrochemical cultivation, supplies these bacteria with a steady supply of electrons that the bacteria use to respire or 'breathe'. It opens the possibility that one day electricity generated from the sources like wind or solar could be funneled to iron oxidising bacteria that combine it with carbon dioxide to create biofuels, capturing the energy as a useful, storable substances.


          "Its a new way to cultivate a microorganism that's been difficult to study. But the fact that these organisms can synthesize everything they need using only electricity," says Daniel Bond of the University of Minnesota.


           To 'breathe', iron oxidisers take electrons off of dissolved iron, called Fe (II) - a process that produces copious amounts of rust, called Fe (III). Iron oxidising bacteria are found around world. Scientist think these bacteria must carry out the iron oxidation step on their surfaces. If that's true, Bond reasoned, the outsides of the organisms should be covered with proteins that interact with Fe (II), so you should be able provide a stream of pure electrons to the outsides and get them to grow.


            Bond and his colleagues added the marine iron oxidiser Mariprofundus ferrooxydans PV -1, along with some nutrient medium, to an electrode carefully tuned to provide electrons at the same energy level, or potential, as Fe (II) would provide. The idea, says Bond, was to "fool the bacteria into thinking they're at the world's best buffet of Fe (II) atoms."


            It worked. The bacteria multiplied and formed a film on the electrode, Bond says, and eventually they were able to grow M ferrooxydans with no iron in the medium.


            "Bacteria are experts at the capture of carbon dioxide. They build cells and compounds" with the carbon, he says. They might one day be exploited as microscopic energy packagers : Bacteria like M ferrooxydans could capture electricity from an electrode, combine it with carbon dioxide and package it as a carbon rich compound we could use as fuel.

Article from MUMBAI MIRROR NEWSPAPER