Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA.
Department of Civil and Environmental Engineering, Technical University of Catalunya, Barcelona-Tech, Spain.
Int Microbiol. 2017 Jun;20(2):55-64. doi: 10.2436/20.1501.01.285.
Power generation in microbial fuel cells implemented in constructed wetlands (CW-MFCs) is low despite the enrichment of anode electricigens most closely related to Geobacter lovleyi. Using the model representative G. lovleyi strain SZ, we show that acetate, but not formate or lactate, can be oxidized efficiently but growth is limited by the high sensitivity of the bacterium to oxygen. Acetate and highly reducing conditions also supported the growth of anode biofilms but only at optimal anode potentials (450 mV vs. standard hydrogen electrode). Still, electrode coverage was poor and current densities, low, consistent with the lack of key c-type cytochromes. The results suggest that the low oxygen tolerance of G. lovleyi and inability to efficiently colonize and form electroactive biofilms on the electrodes while oxidizing the range of electron donors available in constructed wetlands limits MFC performance. The implications of these findings for the optimization of CW-MFCs are discussed. [Int Microbiol 20(2):55-64 (2017)].
尽管在人工湿地微生物燃料电池（CW-MFC）中阳极电生成菌得到了富集，与 Geobacter lovleyi 关系最密切的阳极电生成菌，但发电效率仍然很低。本文使用模型代表菌株 G. lovleyi SZ 进行研究，结果表明，乙酸盐虽然可以被高效氧化，但由于细菌对氧气的高敏感性，其生长受到限制。乙酸盐和高度还原条件也支持阳极生物膜的生长，但只在最佳阳极电位（450 mV 对标准氢电极）下如此。尽管如此，电极覆盖率仍然很差，电流密度也很低，这与关键 c 型细胞色素的缺乏一致。结果表明，G. lovleyi 的低氧气耐受性以及在氧化人工湿地中可用的一系列电子供体的同时，无法有效地在电极上定殖和形成电活性生物膜，限制了 MFC 的性能。本文讨论了这些发现对优化 CW-MFC 的意义。[国际微生物学杂志 20(2):55-64 (2017)]。
