Comparison of Electrode Reduction Activities of Geobacter sulfurreducens and an Enriched Consortium in an Air-Cathode Microbial Fuel Cell
Comparison of Electrode Reduction Activities of Geobacter sulfurreducens and an Enriched Consortium in an Air-Cathode Microbial Fuel Cell
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DOI：
10.1128/aem.01639-08
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发表时间：
2008-12-01
影响因子：
4.4
通讯作者：
Sekiguchi, Yuji
中科院分区：
文献类型：
--
作者：
Ishii, Shun'ichi;Watanabe, Kazuya;Sekiguchi, Yuji
将一种发电细菌 GeobactersulfurreducensPCA 接种到单室空气阴极微生物燃料电池 (MFC) 中，以确定从细菌到阳极的最大电子转移率。为了创造阳极反应限制条件，其中从细菌到阳极的电子转移是速率限制步骤，具有生电生物膜的阳极尺寸被减小，并使用六种不同尺寸的阳极进行测试。由于电极上的细菌质量有限，最小的阳极（7 cm(2)，或比阴极大 1.5 倍）达到了阳极反应限制条件。在此条件下，极限电流密度达到最大值1,530 mA/m(2)，功率密度达到最大值461 mW/m(2)。电子转移速率的单位生物质效率恒定为 32 fmol cell(-1) day(-1) (178 mu mol g 蛋白质(-1) min(-1))，该速率与以固体铁作为电子受体的速率相当，但低于用富马酸盐或可溶性铁实现的速率。相比之下，在相同条件下，富集的发电财团的蛋白质(-1) min(-1)达到374 mu mol g，这表明该财团具有更大的电极还原能力。这些结果表明，每个生物质的电极还原率（通过阳极上的电流密度和生物质密度计算）可用于帮助更好地比较 MFC 中的生电活动。
An electricity-generating bacterium, Geobacter sulfurreducens PCA, was inoculated into a single-chamber, air-cathode microbial fuel cell (MFC) in order to determine the maximum electron transfer rate from bacteria to the anode. To create anodic reaction-limiting conditions, where electron transfer from bacteria to the anode is the rate-limiting step, anodes with electrogenic biofilms were reduced in size and tests were conducted using anodes of six different sizes. The smallest anode (7 cm(2), or 1.5 times larger than the cathode) achieved an anodic reaction-limiting condition as a result of a limited mass of bacteria on the electrode. Under these conditions, the limiting current density reached a maximum of 1,530 mA/m(2), and power density reached a maximum of 461 mW/m(2). Per-biomass efficiency of the electron transfer rate was constant at 32 fmol cell(-1) day(-1) (178 mu mol g of protein(-1) min(-1)), a rate comparable to that with solid iron as the electron acceptor but lower than rates achieved with fumarate or soluble iron. In comparison, an enriched electricity-generating consortium reached 374 mu mol g of protein(-1) min(-1) under the same conditions, suggesting that the consortium had a much greater capacity for electrode reduction. These results demonstrate that per-biomass electrode reduction rates (calculated by current density and biomass density on the anode) can be used to help make better comparisons of electrogenic activity in MFCs.