Quantification of Electron Transfer Rates to a Solid Phase Electron Acceptor through the Stages of Biofilm Formation from Single Cells to Multicellular Communities

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• 作者：Jeffrey S. McLean ; Greg Wanger ; Yuri A. Gorby ; Martin Wainstein ; Jeff McQuaid ; Shun’ ; ichi Ishii ; Orianna Bretschger ; Haluk Beyenal ; Kenneth H. Nealson
• 刊名：Environmental Science & Technology
• 出版年：2010
• 出版时间：April 1, 2010
• 年：2010
• 卷：44
• 期：7
• 页码：2721-2727
• 全文大小：309K
• 年卷期：v.44,no.7(April 1, 2010)
• ISSN：1520-5851

文摘

Microbial fuel cell (MFC) technology has enabled new insights into the mechanisms of electron transfer from dissimilatory metal reducing bacteria to a solid phase electron acceptor. Using solid electrodes as electron acceptors enables quantitative real-time measurements of electron transfer rates to these surfaces. We describe here an optically accessible, dual anode, continuous flow MFC that enables real-time microscopic imaging of anode populations as they develop from single attached cells to a mature biofilms. We used this system to characterize how differences in external resistance affect cellular electron transfer rates on a per cell basis and overall biofilm development in Shewanella oneidensis strain MR-1. When a low external resistance (100 Ω) was used, estimates of current per cell reached a maximum of 204 fA/cell (1.3 × 10⁶ e⁻ cell⁻¹ sec⁻¹), while when a higher (1 MΩ) resistance was used, only 75 fA/cell (0.4 × 10⁶ e⁻ cell⁻¹ sec⁻¹) was produced. The 1 MΩ anode biomass consistently developed into a mature thick biofilm with tower morphology (>50 μm thick), whereas only a thin biofilm (<5 μm thick) was observed on the 100 Ω anode. These data suggest a link between the ability of a surface to accept electrons and biofilm structure development.