Department of Material Sciences and Chemical Engineering, Shizuoka University, Hamamatsu, Shizuoka 432-8561, Japan.
J Biosci Bioeng. 2013 Jul;116(1):106-13. doi: 10.1016/j.jbiosc.2013.01.019. Epub 2013 Mar 13.
It is important for practical use of microbial fuel cells (MFCs) to not only develop electrodes and proton exchange membranes but also to understand the bacterial community structure related to electricity generation. Four lactate fed MFCs equipped with different membrane electrode assemblies (MEAs) were constructed with paddy field soil as inoculum. The MEAs significantly affected the electricity-generating properties of the MFCs. MEA-I was made with Nafion 117 solution and the other MEAs were made with different configurations of three kinds of polymers. MFC-I equipped with MEA-I exhibited the highest performance with a stable current density of 55 ± 3 mA m⁻². MFC-III equipped with MEA-III with the highest platinum concentration, exhibited the lowest performance with a stable current density of 1.7 ± 0.1 mA m⁻². SEM observation revealed that there were cracks on MEA-III. These results demonstrated that it is significantly important to prevent oxygen-intrusion for improved MFC performance. By comparing the data of DGGE and phylogenetic analyzes, it was suggested that the dominant bacterial communities of MFC-I were constructed with lactate-fermenters and Fe(III)-reducers, which consisted of bacteria affiliated with the genera of Enterobacter, Dechlorosoma, Pelobacter, Desulfovibrio, Propioniferax, Pelosinus, and Firmicutes. A bacterium sharing 100% similarity to one of the DGGE bands was isolated from MFC-I. The 16S rRNA gene sequence of the isolate shared 98% similarity to gram-positive Propioniferax sp. P7 and it was confirmed that the isolate produced electricity in an MFC. These results suggested that these bacteria are valuable for constructing the electron transfer network in MFC.
对于微生物燃料电池（MFC）的实际应用，不仅要开发电极和质子交换膜，还要了解与发电相关的细菌群落结构。以稻田土为接种物，构建了 4 个以乳酸为底物的 MFC，配备了不同的膜电极组件（MEA）。MEA 显著影响 MFC 的发电性能。MEA-I 由 Nafion 117 溶液制成，其他 MEA 由三种聚合物的不同组合制成。配备 MEA-I 的 MFC-I 表现出最高的性能，稳定电流密度为 55 ± 3 mA m⁻²。配备 MEA-III（铂浓度最高）的 MFC-III 表现出最低的性能，稳定电流密度为 1.7 ± 0.1 mA m⁻²。SEM 观察表明 MEA-III 上有裂缝。这些结果表明，为了提高 MFC 的性能，防止氧气侵入非常重要。通过比较 DGGE 和系统发育分析的数据，表明 MFC-I 的优势细菌群落是由乳酸发酵菌和 Fe(III)还原菌构建的，其中包括与肠杆菌属、脱氯弧菌属、Pelobacter 属、脱硫弧菌属、丙酸菌属、Pelosinus 属和厚壁菌门相关的细菌。从 MFC-I 中分离出与 DGGE 带之一相似度为 100%的细菌。分离株的 16S rRNA 基因序列与阳性革兰氏丙酸菌属 P7 相似度为 98%，并证实该分离株在 MFC 中产生电能。这些结果表明，这些细菌对于构建 MFC 中的电子传递网络具有重要价值。
