MORE | Spring 2022

Cryogenic Electron Tomography and 3D Reconstructions of the Intracellular Extracellular Nanowire Interface of Geobacter Sulfurreducens

Geobacter sulfurreducens are bacteria that use cellular respiration to naturally convert carbon substrates into harvestable electricity. Important morphological information of two structures involved in this process remains to be elucidated: conductive protein filaments, called microbial nanowires, and intracytoplasmic membranes (ICMs). In this work, cryo-electron tomography (cryo-ET), transmission electron microscopy (TEM) and confocal microscopy were used to image and model G. sulfurreducens nanowires and ICMs. These images reveal that nanowires appear to extend past the outer membrane and grow preferentially towards the anode, and that ICMs are induced more frequently when G. sulfurreducens is grown with insoluble solid-surface electron acceptors.