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Bacteria can be engineered to produce electricity

This could help us with wastewater cleanup

An extreme closeup of electrogenic bacteria colonizing the electrode surface, where current is collected 
Nathan D. Kirchhofer

Bacteria can be chemically engineered to produce electricity, according to new research. In the future, this kind of method could be used to help clean water in wastewater treatment plants.

Some bacteria generate electricity naturally as part of their metabolism, using special proteins in their cell membranes. But these bacteria usually live in extreme environments. For a study published today in the journal Chem, researchers engineered a molecule they can insert inside other bacteria to restore that ability. First, they created a special molecule called DFSO+ that contains a metal (specifically iron) atom. Next, they added DFSO+ to a bacteria called Shewanella oneidensis. The synthetic molecule went through the cell membrane and began to interact with the bacteria to conduct electrical current by using the iron atom.

Some strains of S. oneidensis can already do this. They intake metal minerals and electrodes to generate electricity. But because they usually live in areas without oxygen and so their application is more limited. For this experiment, the scientists used strains of S. oneidensis that had been engineered to not be able to generate electricity. DFSO+ could stay in the bacteria for weeks, so the effect could last for a decent amount of time.

Test tubes containing purified crystals of DSFO(Me)4, a model compound used in the study.
Photo by Zachary Rengert

By restoring this ability, it suggests that we’ll be able to make many different kinds of bacteria generate electricity, which could be very helpful. This is a preliminary step, and the bacteria probably can’t generate enough electricity to power anything big. Still, they could, for example, produce enough electricity to clean the water in treatment plants. Plus, using this chemical method might be cheaper than genetically engineering bacteria. And it could lead to more efficient electricity-generating technology in the future.