A New Electro-Active Bacterium, Paraclostridium Sp. AKS46, Converts Waste Efficiently into Electricity in Microbial Fuel Cell

Microbial fuel cell (MFC) has gained importance for its ability to convert waste into energy. Exoelectrogens are the essential component of MFC that plays an important role in determining the efficiency of MFC. Therefore, the current study aimed at isolating efficient exoelectrogen(s) with significant biodegradation ability. Based on iron reduction ability, the current study isolated a bacterium that exhibited a high level of current generation and significant COD reduction (58–70%) of the medium/waste used in MFC. The maximum current density achieved in the 80 ml capacity of two electrodes MFC by the new isolate was 632 mA/m2. The ribotyping analysis identified this isolate as a member of the Paraclostridium genera and named Paraclostridium sp. AKS46. Further study revealed that this new isolate is capable of forming a biofilm on the anode, and the result showed a positive correlation of this biofilm formation with the current generation. Field emission-scanning electron microscopy (SEM), energy dispersive X-ray-SEM, Fourier transform infrared spectroscopy, gas chromatography-mass spectroscopy, and high-performance liquid chromatography analysis of the AKS46 reveal multiple electron transfer routes to the electrode surface. Furthermore, this new isolate was found to be capable of utilizing diverse carbon sources and thus generated current efficiently using different household wastes in MFC. Hence, the present study isolated an efficient exoelectrogen, Paraclostridium sp. AKS46, which can generate a high level of electricity with a significant reduction of COD of diverse wastes. Thus the new isolate has the potential to be used in MFC for sustainable development.