Research On E.coli Microbial Fuel Cell

Because of energy shortage,it has become a common sense to develop new types of clean energy and adjust energy structure in world.Microbial fuel cell (MFC)is just a new type of device which generates electricity by using microbes.In this paper,an indirect microbial fuel cell(MFC)was constructed by using E.coli as the biocatalyst,methylene blue as the electron mediator,glucose as the electron donor,and potassium ferricyanide as the electron acceptor;the electricity generation of E.coli MFC was tested:when the E.coli cells' initial concentration was 3.41mg dry cell weight/ml,the MFC's maximum power density was 263.94mW/m² with the corresponding current density 1287.50mA/m²;the internal resistance of MFC was 200Ω;experiments proved that E.coli MFC exhibited a good electrochemical cycle property,can be used as a rechargeable cell;and also proved that MFC's electricity generation mainly attributed to the electrochemically and biologically active cells attached to the electrode,while the suspended cells had no ability to catalyze electricity generation and almost had no electrochemically and biologically active,and the formation of mature biofilm attached to the anode is extremely important to the MFC's electricity generation.At the same time,online taming method was adopted to improve E.coli's electrochemical activity,namely a combination of taming E.coli and generating electricity simultaneously in the same that MFC,which did not need scrap off the MFC's biofilm.After the 4^thonline taming,the electricity generation of the tamed E.coli MFC was compared with the electricity generation of the parental E.coli MFC when the E.coli cells' initial concentration was 1.24mg dry cell weight/ml,the tamed E.coli MFC showed a 54%improvement in peak current density,which reached to 612.50mA/m²;a 64%improvement in the maximum power output, which reached to 166.67mW/m².Meantime,the tamed biofilm's maturation time was obviously reduced to 240 min,quickened up 1 times compared the parental E.coli's.The online taming method described here does not need scrap off biofilm,has the strong points of the less taming-times and the shorter taming-time.