Microbial electrochemistry

Microbes obtain energy by oxidizing an electron donor with low potential and reducing an electron acceptor with higher potential. Recently, it was discovered that some microbes can utilize a solid electrode as electron donor or acceptor and, thus, serve as living catalysts for electrochemical reactions. This microbial electrochemical system could potentially be used for a range of different processes. We investigate fundamental aspects of microbial electrochemistry and develop new processes that could be of industrial relevance, for example in the field of wastewater treatment.

One focus area is microbial electrosynthesis, which refers to a process where microorganisms accept electrons from a cathode and synthesize a chemical by reducing a soluble electron acceptor. For example, carbon dioxide can be reduced to acetate. Currently, very little is known about electrosynthesis functions in microorganisms. Our project aims to answer: Which microorganisms can carry out the process? How do they obtain electrons from the cathode surface? What products can they produce? This project is funded by VR, the ERC, and the Magnus Bergvall foundation.

Another area of research is metal recovery from dilute solutions. Valuable metals can be leached out from solid waste incineration ashes using e.g. acids. To recover the metals from the leachates electrolysis must be carried out, which is very energy consuming. In a microbial electrochemical system, we can utilize the energy content of organic compounds in wastewater to recover the metals. For example, copper can be recovered without a net input of electrical energy. This project is funded by Avfall Sverige, KVVS Göteborg, and Renova AB.

A third area of research is the development of BOD sensors based on microbial electrochemical technology. This project does not currently have dedicated funding.