关键词: 厌氧产电菌, 分离, 生理生化特征, 电化学活性

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