Chemistry Division, Naval Research Laboratory, 4555 Overlook Ave., S.W., Washington, DC 20375, USA.
Biosens Bioelectron. 2012 Jan 15;31(1):492-8. doi: 10.1016/j.bios.2011.11.024. Epub 2011 Nov 22.
There are several interconnected metabolic pathways in bacteria essential for the conversion of carbon electron sources directly into electrical currents using microbial fuel cells (MFCs). This study establishes a direct exogenous method to increase power output from a Shewanella oneidensis MR-1 containing MFC by adding calcium chloride to the culture medium. The current output from each CaCl(2) concentration tested revealed that the addition of CaCl(2) to 1400 μM increased the current density by >80% (0.95-1.76 μA/cm(2)) using sodium lactate as the sole carbon source. Furthermore, polarization curves showed that the maximum power output could be increased from 157 to 330 μW with the addition of 2080 μM CaCl(2). Since the conductivity of the culture medium did not change after the addition of CaCl(2) (confirmed by EIS and bulk conductivity measurements), this increase in power was primarily biological and not based on ionic effects. Thus, controlling the concentration of CaCl(2) is a pathway to increase the efficiency and performance of S. oneidensis MR-1 MFCs.
在利用微生物燃料电池（MFC）将碳电子源直接转化为电流的过程中，细菌中有几个相互关联的代谢途径是必不可少的。本研究通过在培养基中添加氯化钙，建立了一种直接的外源方法来提高含有 Shewanella oneidensis MR-1 的 MFC 的输出功率。测试的每种 CaCl2 浓度的电流输出表明，添加 1400 μM 的 CaCl2 可将电流密度提高>80%（0.95-1.76 μA/cm2），此时唯一的碳源是乳酸钠。此外，极化曲线表明，添加 2080 μM CaCl2 可将最大功率输出从 157 增加到 330 μW。由于添加 CaCl2 后培养基的电导率没有变化（通过 EIS 和体电导率测量得到证实），因此这种功率的增加主要是生物的，而不是基于离子效应。因此，控制 CaCl2 的浓度是提高 S. oneidensis MR-1 MFC 效率和性能的途径。
