Bioelectrical Potential of Escherichia Coli Recovered From Medical and Environmental Sources

The increasing global demand for sustainable energy accelerates the development of microbial fuel cells (MFCs), which utilize bacterial metabolism to generate electricity. This study addresses a critical gap in this field by investigating how the native environment of Escherichia coli influences its electrogenic potential. The research therefore aims to evaluate and contrast the bioelectricity generation of E. coli isolates sourced from wound, urine, and water samples. Guided by the theoretical framework of extracellular electron transfer, which posits that a bacterium's metabolic adaptations to its habitat directly impact its electron-shuttling efficiency, the study employs a standardized dual-chamber MFC. Isolates are cultured and identified using established microbiological techniques before being introduced into the MFC, which is equipped with a carbon paper anode and a Nafion®117 proton exchange membrane. Voltage and current outputs are meticulously recorded over a seven-day period. The results demonstrates that all E. coli isolates are capable of producing electricity, but their performance varies significantly based on their origin. The urine-derived isolate yields the highest and most stable output, peaking at 2.53 V and 1.27 A. The wound isolate shows a consistent increase, reaching 1.93 V and 0.67 A, while the water isolate produces the lowest and most declining output, with a maximum of 1.42 V and 0.39 A. The study concludes that the source of an E. coli isolate is a decisive factor in its electrogenic performance, with strains from nutrient-rich environments like urine holding the greatest promise. It is recommended that future MFC research prioritizes the selection of bacterial inocula based on their ecological background and explores the specific genetic and metabolic mechanisms underpinning these performance differences to optimize bioenergy systems.