Nonlocal bacterial electron transfer to hematite surfaces

Authors

Kevin Rosso, Pacific Northwest National LaboratoryFollow
John M. Zachara, Pacific Northwest National LaboratoryFollow
James K. Fredrickson, Pacific Northwest National LaboratoryFollow
Yuri Gorby, Pacific Northwest National Laboratory
Steven Smith, Pacific Northwest National LaboratoryFollow

Date of this Version

2003

Citation

Geochimica et Cosmochimica Acta, Vol. 67, No. 5, pp. 1081–1087, 2003

Abstract

Mechanisms by which dissimilatory iron-reducing bacteria utilize iron and manganese oxide minerals as terminal electron acceptors for respiration are poorly understood. In the absence of exogenous electron shuttle compounds, extracellular electron transfer is generally thought to occur through the interfacial contact area between mineral surfaces and attached cells. Possible alternative reduction pathways have been proposed based on the discovery of a link between an excreted quinone and dissimilatory reduction. In this study, we utilize a novel experimental approach to demonstrate that Shewanella putrefaciens reduces the surface of crystalline iron oxides at spatial locations that are distinct from points of attachment.