Rabaey Korneel, Boon Nico, Höfte Monica, Verstraete Willy
Laboratory of Microbial Ecology and Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
Environ Sci Technol. 2005 May 1;39(9):3401-8. doi: 10.1021/es048563o.
High-rate electron transfer toward an anode in microbial fuel cells (MFCs) has thus far not been described for bacteria-producing soluble redox mediators. To studythe mechanism of electron transfer, we used a MFC isolate, Pseudomonas aeruginosa strain KRP1. Bacterial electron transfer toward the MFC anode was enabled through pyocyanin and phenazine-1-carboxamide. The presence of the anode stimulated pyocyanin production. Mutant strains, deficient in the synthesis of pyocyanin and phenazine-1-carboxamide, were unable to achieve substantial electron transfer and reached only 5% of the wild type's power output. Upon pyocyanin addition, the power output was restored to 50%. Pyocyanin was not only used by P. aeruginosa to improve electron transfer but as well enhanced electron transfer by other bacterial species. The finding that one bacterium can produce electron shuttles, which can be used also by other bacteria, to enhance electron-transfer rate and growth, has not been shown before. These findings have considerable implications with respect to the power output attainable in MFCs.
迄今为止，尚未有关于产生可溶性氧化还原介质的细菌在微生物燃料电池（MFC）中向阳极进行高速率电子转移的描述。为了研究电子转移机制，我们使用了一株MFC分离菌——铜绿假单胞菌KRP1菌株。细菌通过绿脓菌素和吩嗪 - 1 - 甲酰胺实现向MFC阳极的电子转移。阳极的存在刺激了绿脓菌素的产生。缺乏绿脓菌素和吩嗪 - 1 - 甲酰胺合成能力的突变菌株无法实现大量电子转移，其功率输出仅达到野生型的5%。添加绿脓菌素后，功率输出恢复到50%。绿脓菌素不仅被铜绿假单胞菌用于改善电子转移，还能增强其他细菌种类的电子转移。一种细菌能够产生可被其他细菌利用的电子穿梭体以提高电子转移速率和促进生长，这一发现此前尚未见报道。这些发现对于MFC中可实现的功率输出具有重要意义。
