Role of humic-bound iron as an electron transfer agent in dissimilatory Fe(III) reduction

Appl Environ Microbiol. 1999 Sep;65(9):4252-4. doi: 10.1128/AEM.65.9.4252-4254.1999.


The dissimilatory Fe(III) reducer Geobacter metallireducens reduced Fe(III) bound in humic substances, but the concentrations of Fe(III) in a wide range of highly purified humic substances were too low to account for a significant portion of the electron-accepting capacities of the humic substances. Furthermore, once reduced, the iron in humic substances could not transfer electrons to Fe(III) oxide. These results suggest that other electron-accepting moieties in humic substances, such as quinones, are the important electron-accepting and shuttling agents under Fe(III)-reducing conditions.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Deltaproteobacteria / metabolism*
  • Electron Transport
  • Ferric Compounds / metabolism*
  • Humic Substances / chemistry
  • Humic Substances / metabolism*
  • Iron / metabolism*
  • Oxidation-Reduction


  • Ferric Compounds
  • Humic Substances
  • Iron