Faculty of Materials & Energy, Chongqing Key Laboratory for Advanced Materials & Technologies of Clean Energies, Southwest University, Chongqing 400715, China.
Faculty of Materials & Energy, Chongqing Key Laboratory for Advanced Materials & Technologies of Clean Energies, Southwest University, Chongqing 400715, China.
Bioelectrochemistry. 2017 Oct;117:34-39. doi: 10.1016/j.bioelechem.2017.04.003. Epub 2017 May 23.
Bacteria biofilm plays a key role in current generation of microbial fuel cells (MFCs), especially for the start-up stage. However, the detailed mechanism of the biofilm promoting the power generation is not very clear so far, especially for those exoelectrogens who rely on the self-excreted electron mediators for extracellular electron transfer. In this work, a biofilm formation inhibitor-sodium houttuyfonate (SH) is used to build a "non-biofilm" anode of Pseudomonas aeruginosa (P. aeruginosa) without affecting the bacteria growth during the MFC operation. According to the comparison results of the "non-biofilm" anode and biofilm-covered anode on current generation, phenazines concentration variation and anodic electrocatalysis, the biofilm on the anode not only provides plenty of bacterial cells for catalysis but also promotes the interfacial phenazine redox reaction through accumulating the self-generated mediators on anode for fast interfacial electron transfer. This work proves that the biofilm assisted electron mediator accumulation will benefit such kind of exoelectrogens to sustain sufficient electron mediators for extracellular electron transfer.
细菌生物膜在当前一代微生物燃料电池 (MFC) 中起着关键作用，尤其是在启动阶段。然而，到目前为止，生物膜促进发电的详细机制还不是很清楚，特别是对于那些依赖自身分泌的电子介体进行细胞外电子转移的外电子受体。在这项工作中，使用生物膜形成抑制剂-虎杖次酸钠 (SH) 构建了铜绿假单胞菌 (P. aeruginosa) 的“无生物膜”阳极，在 MFC 运行过程中不会影响细菌的生长。根据“无生物膜”阳极和生物膜覆盖阳极在电流产生、苯醌浓度变化和阳极电催化方面的比较结果，阳极上的生物膜不仅为催化提供了大量的细菌细胞，而且还通过在阳极上积累自身产生的介体来促进界面苯醌氧化还原反应，从而实现快速的界面电子转移。这项工作证明，生物膜辅助电子介体积累将有利于这类外电子受体维持足够的电子介体进行细胞外电子转移。
