Wu Song, Xiao Yong, Zheng Zhi-Yong, Zheng Yue, Yang Zhao-Hui, Zhao Feng
Huan Jing Ke Xue. 2014 Oct;35(10):3933-9.
Extracellular electron transfer of electrochemically active microorganism plays vital role in biogeochemical cycling of metals and carbon and in biosynthesis of bioenergy. Compared to anaerobic anode, micro-aerobic anode captures more energy from microbial fuel cell. However, most of previous researches focused on functioning bacteria in anaerobic anode, functioning bacteria in micro-aerobic anode was rarely studied. Herein, we used the traditional aerobic screening technology to isolate functioning bacteria from a micro-aerobic anode. Three pure cultures Aeromonas sp. WS-XY2, Citrobacter sp. WS-XY3 and Bacterium strain WS-XY4 were obtained. WS-XY2 and WS-XY3 were belonged to Proteobacteria, whereas WS-XY4 was possibly a new species. Cyclic voltammetry and chronoamperometry analysis demonstrated all of them showed the electrochemical activity by direct extracellular electron transfer, and micro-aerobic anode could select bacteria that have similar electrochemical activity to proliferate on the anode. We further conclude that functioning bacteria in micro-aerobic anode are more efficient than that of anaerobic anode may be the reason that micro-aerobic anode has better performance than anaerobic anode. Therefore, a thorough study of functioning bacteria in micro-aerobic anode will significantly promote the energy recovery from microbial fuel cell.
电化学活性微生物的胞外电子转移在金属和碳的生物地球化学循环以及生物能源的生物合成中起着至关重要的作用。与厌氧阳极相比，微需氧阳极能从微生物燃料电池中捕获更多能量。然而，以往的大多数研究都集中在厌氧阳极中的功能细菌，对微需氧阳极中的功能细菌研究较少。在此，我们使用传统的好氧筛选技术从微需氧阳极中分离功能细菌。获得了三种纯培养物，即气单胞菌属WS-XY2、柠檬酸杆菌属WS-XY3和菌株WS-XY4。WS-XY2和WS-XY3属于变形菌门，而WS-XY4可能是一个新物种。循环伏安法和计时电流法分析表明，它们都通过直接胞外电子转移表现出电化学活性，并且微需氧阳极可以选择具有相似电化学活性的细菌在阳极上增殖。我们进一步得出结论，微需氧阳极中的功能细菌比厌氧阳极中的功能细菌更高效，这可能是微需氧阳极性能优于厌氧阳极的原因。因此，对微需氧阳极中功能细菌的深入研究将显著促进微生物燃料电池的能量回收。
