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Mingdong_Dong_Jie_Song_Nils Risgaard-Petersen

Microsensors used for sensational discovery

Scientists from Aarhus University have sensationally discovered bacteria that function as living electrical cables. Head of research group, Prof. Lars Peter Nielsen, gave a lecture on this research at a Unisense workshop back in August 2011 explaining:

 “The electrical current was discovered only using microsensors”, Prof. Lars Peter Nielsen says. “It started out as a very conventional study about sulfide oxidation in marine sediments. But in time, the microprofiles obtained in the sediment samples could not be explained by conventional theories and we were stuck with the observation”.

Since then the scientists have been searching for an explanation and together with partners from the University of Southern California, USA, they now present sensational results in Nature.

In microscopes, scientists found an unknown type of long, multi-cellular bacteria that was always present when scientists measured the electric currents. This current could be interrupted by pulling a thin wire horizontally through the sediment cores, indicating that the electric connections in the seabed were solid structures.

The filamentous bacteria connect oxygen reduction at the surface with sulfide oxidation in the subsurface by transporting electrons from the anoxic zone to the oxygenated surface, even when oxygen and sulfide are separated more than 1 cm. This explained the mysterious observations found in the sediment samples.

At the workshop Prof. Lars Peter Nielsen wants to put forward the message to the participants: “You should always believe in your data! Do not blame Unisense or somebody else that your experiments do not show what you expect. It might be that you are opening a door no one has entered before”.
Unisense congratulates the research team on their great achievements!

The article in Nature:
Filamentous bacteria transport electrons over centimetre distances” by Christian Pfeffer, Steffen Larsen, Jie Song, Mingdong Dong, Flemming Besenbacher, Rikke Louise Meyer, Kasper Urup Kjeldsen, Lars Schreiber, Yuri A. Gorby, Mohamed Y. El-Naggar, Kar Man Leung, Andreas Schramm, Nils Risgaard-Petersen & Lars Peter Nielsen. DOI:10.1038/nature11586.