微生物燃料电池利用乳酸产电性能与微生物群落分布特征

Electricity generation from lactate using microbial fuel cell and the distribution characteristics of anode microbial community

【目的】为探讨以乳酸为基质的微生物燃料电池(Microbial fuel cell,MFC)产电性能以及微生物群落在阳极膜、悬浮液、阳极沉淀污泥中的分布特征,【方法】试验建立了双室MFC,以乳酸为阳极主要碳源,研究了反应器的启动过程及产电效能,同时以电镜和PCR-变性梯度凝胶电泳(Denaturing gradient gelelectrophoresis,DGGE)技术解析了微生物群落的空间分布特征。【结果】结果表明,反应器启动第7天时外电压达到0.56 V,当外阻为80Ω时,电流密度为415 mA/m2,MFC的功率密度达到最大值82 mW/m2。电镜观察发现大量杆菌附着在阳极表面,结合较为紧密;DGGE图谱显示阳极膜表面微生物与种泥最为相似,与阳极悬浮液、底部沉淀污泥中的主要菌群一致,条带序列与睾丸酮丛毛单胞菌(Comamonas testosteroni)和布氏弓形菌(Arcobacter butzleri)等最为相似。【结论】本研究表明以乳酸为基质MFC可产生较高的功率密度,阳极附着的优势菌与接种污泥来源密切相关。

[ Objective] Two-chamber microbial fuel cells （MFCs） were set up to understand the electrogenic capacity of MFCs fed with lactic acid to investigate the distribution characteristics of mieroflora in the anode biofilm, supernatant, and sediment. [ Methods] Using lactic acid as a carbon source in the anode, we explored the MFCs start-up process and the efficiency of electricity production, and also investigated the spatial distribution of microbial communities using scanning electron microscope （SEM） and PCR-denaturing gradient gel electrophoresis （DGGE） techniques. [ Results~ The results indicate that the MFCs reached the highest voltage, 0.56 V on the seventh day after startup. When external resistance and current density was 80 ~ and 415 mA/m2, respectively, the power density reached its maximum at 82 mW/m2. SEM revealed that a massive bacillus was attached tightly to the surface of the positive electrode. DGGE profiles revealed that microorganisms on the anode＇s surface were most similar to that of inoculated sludge, consistent with the major microorganism groups in anode suspension and sludge substrate. Communities developed on the anodes included exoelectrogenic bacteria, i.e. Comamonas testosterone, and Arcobacter butzleri. [ Conclusion] This research demonstrates that MFCs fed with lactic acid can generate a high efficiency of current density, and that the dominant microbes on the anodes are similar to that of inoculated sludge