Electricity production from paddy soil in double chamber microbial fuel cells and isolation of the electroactive bacteria involved

Microbial fuel cells have recently garnered attention due to the growing interest in producing sustainable energy. Submerged paddy soil creates an environment with low levels of oxygen, known as microaerophilic, and contains a significant amount of organic matter. Consequently, it prevents the decomposition of organic materials and retards their decomposition. Diversification of EAB may differ based on the type of medium used. Hence, this study aimed to construct functional DMFCs using a salt bridge design and isolate EAB from paddy soil enriched in DMFCs. Soil samples were collected from a specific paddy field from Machang, Kelantan, enrichment of the paddy soil in MFCs, soil DNA extraction, isolation and cultivation of bacteria, and characterization of the bacteria using biochemical tests. Functionality of DMFCs could be observed by observing the colour changes of potassium ferricyanide due to the reduction process. Remarkable improvement in power density during the experiment, notably in the second enrichment setup, showed a very significant difference with a 40-fold increment. Maximum value of power density for first enrichment setup was 22.300 W/m2 while the second enrichment setup was 1208.830 W/m². This study reported three bacterial strains (MC-1, MC-2, and MC-3) were isolated from the second DMFCs. In conclusion, EAB from paddy soil can generate electricity and significantly contributes to advancing our comprehension of EAB behavior in paddy soil within the flooded habitat. These findings highlight the potential of paddy soil as a resource for sustainable energy production through microbial fuel cell technology.