Genetic engineering of shewanella oneidensis MR-1 for boosting electricity output in microbial fuel cells

Shewanella oneidensis MR-1(S.oneidensis MR-1), a model species of the proteobacteria Shewanella, is a commonly used microorganism in Microbial Fuel Cells (MFCs) due to its signature feature of extracellular metal reduction. A MFC has the potential to convert chemical energy from a biological substrate into electrical energy. S.oneidensis MR-1 resides in the anaerobic anode of the MFC and during respiration feeds on and oxidizes a carbon substrate source. The oxidized carbon source generates electrons that are transported through the electron transfer pathway of the bacterium to finally reduce the extracellular metal electrode of the MFC to produce electricity. S.oneidensis MR-1 possesses unique lactate utilization machinery to utilize lactate as the sole carbon energy source during respiration. Although MFCs have numerous benefits compared to traditional fossil fuels, the bioelectricity yield in MFCs is capped at a low level. One strategy that can be adopted is metabolic engineering of reaction pathways that produce electron carriers such as NADH and NADPH, to increase electrons in the extracellular electron transfer pool, which boosts the current output in a MFC. The metabolic engineering approach focuses on modifying the regulatory processes of specific genes identified to achieve the goal of increased NADH or NADPH concentration. Hence, this review looks into S.oneidensis MR-1’s features and role in a MFC; the principles, advantages and shortcomings of MFCs and the basis for increasing the electricity yield in a MFC.Bachelor of Engineering (Chemical and Biomolecular Engineering