Long-term arsenic monitoring with an Enterobacter cloacae microbial fuel cell

• An E. cloacae MFC was characterized by CV and current ramp potentiometry.
• Biofilms were grown in the absence and presence of inorganic arsenic species.
• Arsenic caused reduced power and current output from the microbial fuel cell.
• Arsenite detection: linear from 0 M to 0.5 M with a detection limit of 4.4 μM.
• Arsenate detection: linear from 0 M to 0.5 M with a detection limit of 46 μM.

A microbial fuel cell was constructed with biofilms of Enterobacter cloacae grown on the anode. Bioelectrocatalysis was observed when the biofilm was grown in media containing sucrose as the carbon source and methylene blue as the mediator. The presence of arsenic caused a decrease in bioelectrocatalytic current. Biofilm growth in the presence of arsenic resulted in lower power outputs whereas addition of arsenic showed no immediate result in power output due to the short term arsenic resistance of the bacteria and slow transport of arsenic across cellular membranes to metabolic enzymes. Calibration curves plotted from the maximum current and maximum power of power curves after growth show that this system is able to quantify both arsenate and arsenate with low detection limits (46 μM for arsenate and 4.4 μM for arsenite). This system could be implemented as a method for long-term monitoring of arsenic concentration in environments where arsenic contamination could occur and alter the metabolism of the organisms resulting in a decrease in power output of the self-powered sensor.