Abstract: Three anaerobic electrogenic bacteria named as Z1，Z2 and Z3 were isolated from a microbial electrolysis cell (MEC) by the method of Hungate roll tube. Phylogenetic analysis based on 16S rDNA gene sequence indicated that strain Z1 belonged to Citrobacter，while both strain Z2 and Z3 belonged to Clostridium. The physiological and biochemical characteristics showed that Z1 was facultative anaerobe，while Z2 and Z3 were strict anaerobes. Z1，Z2 and Z3 could tolerate acidic pH conditions，and the optimum pH level was 5 to 7.5. The optimum temperature of Z1 was 35 ℃，while the optimum temperature of Z2 and Z3 was 30 ℃. The optimum NaCl concentration range of three strains was 0.1% to 2.0%. Sucrose，starch，sodium propionate，sodium acetate could be used as their carbon sources. The study of electrocatalytic activity showed that these strains all had a reduction peak at voltage of ?0.29 V and they were applicable for the cathode of microbial fuel cell (MFC). The adding of a mixture of three kinds of strains might significantly shorten the time of start-up stage of MFC and enhance electricity production efficiency by 18.1%.

Key words: anaerobic electrogenic bacteria, isolation, physiological and biochemical characteristics, electrochemically active

摘要： 采用Hungate厌氧菌培养技术从微生物电解池（MEC）中分离得到3株厌氧产电菌Z1、Z2和Z3。16S rDNA基因测序和系统发育树构建结果表明，Z1属于柠檬酸杆菌属（Citrobacter），Z2和Z3属于梭菌属（Clostridium）。生理生化特性研究表明，Z1为兼性厌氧菌，Z2和Z3为严格厌氧菌；3种菌株能够耐受较酸的pH值条件，在pH值为5～7.5的环境中增殖良好；Z1的最适生长温度为35 ℃，Z2和Z3的最适生长温度为30 ℃；3种菌株的最适NaCl浓度为0.1%～2.0%；均能以蔗糖、淀粉、丙酸钠、乙酸钠等为碳源生长。产电活性测试试验表明，3种菌株在?0.29 V时具有较大还原峰，氧化峰不明显，适用于微生物燃料电池（MFC）的阴极。在MFC的启动试验中，加入3种菌株的混合物后，可显著缩短其启动周期，同时产电效能提高了18.1%。

关键词: 厌氧产电菌, 分离, 生理生化特征, 电化学活性