ABSTRACT
The rise in global energy demands with depleting fossil fuels has triggered the quest for alternative renewable fuels; scarcity of usable water demands a sustainable wastewater treatment technique. As the world’s demands for energy are increasing day by day, the exhaustion of conventional resources is nearing. The upcoming Microbial Electrochemical System (MES) technology has dual benefits of wastewater treatment and energy generation where electricity is produced by conversion of chemical energy contained in bonds of organic compounds, present in the wastewater by bacteria. Extremophilic organisms, which dwell in the otherwise lethal environment, have shown considerable efficiency in MFCs as they are resistent of conditions like extremely low or high pH, temperature, pressure, etc. Their tolerance to such a harsh environment is credited to their evolved metabolic pathways and electron transport system. This chapter aims to describe the idea behind the working principle of MFC, different extreme environments and the role of extremophiles in microbial electrochemical systems. The extracellular electron transport mechanism of these organisms is also briefly discussed in this chapter. MFCs with extremophiles as a catalyst has the rising potential to replace the conventional energy means with its renewable and eco-friendly approach. This chapter highlights the application of different types of extremophiles as biocatalysts in MES and its future prospectus. It explains the principle of different MESs, microbes associated with anode and catabolic pathway (exocellular electron transfer) responsible for microbial oxidation of the substrate. Besides, the physicochemical factors affecting energy harvesting and challenges in MFC operation during electrogenesis are described. The present chapters help the readers to understand the fundamentals of extremophiles bioelectrochemical energy recovery.
