Researchers from Karlsruhe Institute of Technology, Germany, have married microorganisms and materials to A nanocomposite material (purple) conducts electrons released by exoelectrogenic bacteria (green) to generate electricity. Source: Yong Hu et al. achieve a biohybrid system that harnesses bacterially produced electricity.

Exoelectrogenic bacteria, which shuttle electrons through outer membranes to the cell exterior, were encased in a hydrogel scaffold composed of electrically conductive carbon nanotubes and silica nanoparticles and held together with DNA strands. Nurtured with a liquid culture medium, the bacteria populated the matrix of the conductive composite, remained stable for several days and demonstrated electrochemical activity, confirming the use of the hydrogel scaffold in keeping cells viable.

The biohybrid system supported electron flow to an electrode, which ceased after the addition of a DNA-degrading enzyme and subsequent degradation of the material, indicating potential for on-demand power flow.

The bio-based technology could find use in microbial biosensor, bioreactor, battery and fuel cell applications.