生物阴极微生物燃料电池中同步产电反硝化菌的分离鉴定与性能

Multiple denitrification screening mediums were used to isolate and purify denitrifying bacteria from the biocathode of a stably operated MFC-AA/O reactor, and 16S rRNA sequence analysis was conducted to identify the pure strains. The electricity production capacity was tested by inoculating the pure bacterial strains into cathodic chambers of MFCs to screen simultaneous electricity production and denitrification strains. Then, operation temperature and pH of MFC were further optimized. Finally, the electricity production mechanism was analyzed by scanning cyclic voltammetry curve. The results indicated that one isolated strain, identified as Pseudomonas aeruginosa, could achieve simultaneous electricity production and denitrification. The maximum output voltage could reach about 168 mV, and the optimum pH and temperature for denitrification were 7.5 and 30 ℃, respectively. Electrochemical analysis indicated that the simultaneous electricity production and denitrification might be catalyzed by some secretions of Pseudomonas aeruginosa, which could act as mediators to obtain electrons from the electrode and complete nitrates reduction. This study demonstrated that Pseudomonas aeruginosa as a pure electricigen inoculated in cathode chamber of MFC could achieve simultaneous electricity production and denitrification, which might lay a foundation for the practical application of MFC with denitrifying biocathode.