A Comparison of the Rates of Fe(III) Reduction in Synthetic and Bacteriogenic Iron Oxides by Shewanella putrefaciens CN32
Abstract:The susceptibility of various bacteriogenic iron oxides (BIOS) to bacterial Fe(III) reduction was examined. Reduction resulted in complete dissolution of the iron mineral from the surfaces of the Fe-oxidizing consortium. Reduction rates were compared to that of synthetic ferrihydrite (HFO). The reduction rate of HFO (0.162 day- 1) was significantly lower than that of Aspo (Gallionella dominated) BIOS (0.269 day- 1). Two Canadian (Leptothrix dominated) BIOS samples showed statistically equivalent rates of reduction (0.541 day-1 and 0.467 day- 1), which were higher than both Aspo BIOS and HFO. BIOS produced by different iron-oxidizing genera have different susceptibilities to microbial reduction.
Document Type: Research Article
Affiliations: 1: Department of Earth Sciences, University of Ottawa, Ottawa, Ontario, Canada 2: Environmental Technologies Branch, Chalk River Laboratories, Atomic Energy of Canada Ltd., Ontario, Canada 3: Department of Geology, Earth Sciences Centre, Toronto, Ontario, Canada
Publication date: March 1, 2009