The transfer of electrons among molecules is essential to all organisms, microbes are no exception, for this process generates energy by which they need to survive. While some microorganisms living in oxygen-deprived environments have evolved a unique form of breathing that involves excreting and pumping out electrons, have the potential to act as electricity-producing components that can be used in microbial fuel cells (MFCs), which can be put into use of contributing energy. But not just limit to that, by the energy harvesting process of microbial anaerobic digestion, MFCs is a brilliant tool for wastewater treatment, meanwhile, pathogens can also be reduced, which is a quite promising field in ecological restoration. Moreover, MFCs can work as biosensors to measure the solute concentration of wastewater, online monitoring can be realized as to BOD, COD, DO, toxics, etc.
Figure 1. A schematic diagram of microbial fuel cells (Clark, 2016)
In an MFC, microorganisms utilize the substrate of anode to produce electrons and protons, which are transferred from the anode to the cathode under the potential difference between two poles. Therefore, a loop is formed and that is how electricity is generated. Both characteristics of the cell and the range of its application depend hugely on the ability that bacteria generate electrons. Bacteria used in an MFC are mostly facultative anaerobes (mostly from phylum Proteobacteria and phylum Firmicutes), and some obligate anaerobes and obligate aerobes can be utilized as also.
Table 1 Microorganisms in anode MFC
Microbiosci is the premier institution providing professional and comprehensive microbial fuel cells research and development services from strains selection to MFCs structure optimization, to meet your requirements in energy needs and interdisciplinary application.
We specialize in:
• Strain selection: By combining genetic tools (for creating mutations) with our advanced screening techniques (such as microfluidic screening, high-throughput assay screening), we can assist you in mutating cells and select the most suitable for electron transfer.
• MFCs structure optimization: 1) Protons flow through the exchange membrane, modifying or developing suitable membrane replacement materials would surely improve energy conversion efficiency; 2) Anode should be conductive, bio compatible and chemically stable with substrate, thus, developing anode material with the quality of low resistance, high corrosion resistance, high porosity and high specific area will contribute to the quality of MFCs; 3) Electrons and protons recombine at the cathode, developing cost-effective cathode is as well important.
• Interdisciplinary application: MFCs can be used in multiple fields such as biosensor (interdisciplinary with electronics) and desalination and ecological restoration (interdisciplinary with environtology). With a rich network of resources, we can assist you designing schemes to meet your specific needs.
Simply let us know your requirement. We will provide support for each step in your workflow and propose the best strategy for you.
1. Clark D P, Pazdernik N J. Biotechnology (Second Edition). 2016