Cheng Ka Yu, Cord-Ruwisch Ralf, Ho Goen
Faculty of Sustainability, Environment and Life Sciences, Murdoch University, WA 6150, Australia.
Bioelectrochemistry. 2009 Feb;74(2):227-31. doi: 10.1016/j.bioelechem.2008.10.002. Epub 2008 Nov 5.
Electrochemically active bacteria in a microbial fuel cell (MFC) usually exist as a biofilm attached to an electrode surface. Conventional cyclic voltammetry using potentiostat is considered as a powerful and reliable method to study electrochemical behavior of MFC biofilm. In this paper, we introduce a new approach to evaluate redox behavior of an electro-active MFC biofilm without using a potentiostat. Analogous to a conventional cyclic voltammetry study, we controlled the biofilm-electrode potential by computer-feedback controlling the external resistance of an operating MFC. In this way, the MFC can still operate as a "fuel cell" without being "interrupted" by an external device (i.e. potentiostat) that normally does not belong to the system. Relationship between current and biofilm-electrode potential was obtained and showed agreement with a potentiostat-controlled method under similar experimental conditions. The method could be added to our technical repertoire for analysis of bacterial mediator involved in the exocellular electron transfer of a MFC-biofilm, and it could potentially serve as a practical process monitoring method for MFC operation. The application of computer-control components should be further explored to facilitate control, diagnosis as well as optimization of MFC processes.
微生物燃料电池（MFC）中的电化学活性细菌通常以附着在电极表面的生物膜形式存在。使用恒电位仪的传统循环伏安法被认为是研究MFC生物膜电化学行为的一种强大且可靠的方法。在本文中，我们介绍了一种无需使用恒电位仪即可评估电活性MFC生物膜氧化还原行为的新方法。类似于传统的循环伏安法研究，我们通过计算机反馈控制运行中的MFC的外部电阻来控制生物膜-电极电位。通过这种方式，MFC仍可作为“燃料电池”运行，而不会被通常不属于该系统的外部设备（即恒电位仪）“中断”。获得了电流与生物膜-电极电位之间的关系，并表明在相似的实验条件下与恒电位仪控制方法一致。该方法可补充到我们用于分析参与MFC生物膜胞外电子转移的细菌介质的技术方法中，并且它有可能作为MFC运行的一种实用过程监测方法。应进一步探索计算机控制组件的应用，以促进MFC过程的控制、诊断和优化。
