Bioengineering of Bacterial Extracellular Electron Transfer Towards Sustainable Wastewater Treatment

Abstract

Extracellular electron transfer (EET) referring to electron exchange between cells and solid matters is a unique electron transport process in bacteria that enables cells with very special character of electrode respiration. Based on bacterial electrode respiration, various bioelectrochemical systems (BES) for efficient wastewater treatment have been developed during the past decades. Besides augmentation of wastewater treatment, the BES are capable of harvesting the energy and recovery of resources from wastewater and can also produce value-added products by upgrading CO2 that was emitted during wastewater treatment. Therefore, BES hold a great promise to develop an energy-saving, emission-reducing, and economic feasible wastewater treatment approach for sustainable development, while EET efficiency engineering became the key step for the performance optimization of BES. In this chapter, typical EET pathways in several model exoelectrogens were introduced, and the potential of EET engineering for performance improvement of BES was highlighted. Moreover, future research directions for EET and BES engineering were also discussed.