Extracellular electron transfer via microbial nanowires.

TitleExtracellular electron transfer via microbial nanowires.
Publication TypeJournal Article
Year of Publication2005
AuthorsReguera G, McCarthy KD, Mehta T, Nicoll JS, Tuominen MT, Lovley DR
JournalNature
Volume435
Issue7045
Pagination1098-101
Date Published2005 Jun 23
ISSN1476-4687
KeywordsBiotechnology, Electric Conductivity, Electron Transport, Ferric Compounds, Fimbriae Proteins, Fimbriae, Bacterial, Genes, Bacterial, Geobacter, Microscopy, Atomic Force, Microscopy, Electron, Transmission, Mutation, Nanostructures, Phylogeny
Abstract

Microbes that can transfer electrons to extracellular electron acceptors, such as Fe(iii) oxides, are important in organic matter degradation and nutrient cycling in soils and sediments. Previous investigations on electron transfer to Fe(iii) have focused on the role of outer-membrane c-type cytochromes. However, some Fe(iii) reducers lack c-cytochromes. Geobacter species, which are the predominant Fe(iii) reducers in many environments, must directly contact Fe(iii) oxides to reduce them, and produce monolateral pili that were proposed, on the basis of the role of pili in other organisms, to aid in establishing contact with the Fe(iii) oxides. Here we report that a pilus-deficient mutant of Geobacter sulfurreducens could not reduce Fe(iii) oxides but could attach to them. Conducting-probe atomic force microscopy revealed that the pili were highly conductive. These results indicate that the pili of G. sulfurreducens might serve as biological nanowires, transferring electrons from the cell surface to the surface of Fe(iii) oxides. Electron transfer through pili indicates possibilities for other unique cell-surface and cell-cell interactions, and for bioengineering of novel conductive materials.

DOI10.1038/nature03661
Alternate JournalNature
PubMed ID15973408