Bose, ArpitaGardel, Emily JeanetteVidoudez, CharlesParra, ErikaGirguis, Peter2014-09-162014Bose, A., E.J. Gardel, C. Vidoudez, E.A. Parra, and P.R. Girguis. 2014. Electron Uptake by Iron-Oxidizing Phototrophic Bacteria. Nature Communications 5 (February 26): 3391.2041-1723http://nrs.harvard.edu/urn-3:HUL.InstRepos:12872199Oxidation–reduction reactions underlie energy generation in nearly all life forms. Although most organisms use soluble oxidants and reductants, some microbes can access solid-phase materials as electron-acceptors or -donors via extracellular electron transfer. Many studies have focused on the reduction of solid-phase oxidants. Far less is known about electron uptake via microbial extracellular electron transfer, and almost nothing is known about the associated mechanisms. Here we show that the iron-oxidizing photoautotroph Rhodopseudomonas palustris TIE-1 accepts electrons from a poised electrode, with carbon dioxide as the sole carbon source/electron acceptor. Both electron uptake and ruBisCo form I expression are stimulated by light. Electron uptake also occurs in the dark, uncoupled from photosynthesis. Notably, the pioABC operon, which encodes a protein system essential for photoautotrophic growth by ferrous iron oxidation, influences electron uptake. These data reveal a previously unknown metabolic versatility of photoferrotrophs to use extracellular electron transfer for electron uptake.en-USBiological sciencesBiochemistryEcologyMicrobiologyJournal Article2014-09-1610.1038/ncomms4391