Electrochemical interfacing of microbial metabolism

Lead Research Organisation: University of Warwick
Department Name: School of Life Sciences

Abstract

This project will involve the study of microbial electrochemical systems, investigating how they work at a fundamental level and using the knowledge gained to develop new and improved technologies and systems for the electrical interfacing and control of cells.
Existing microbial electrochemical systems use electrical interfacing with microbial metabolism to convert chemical feedstocks into electrical energy (microbial fuel cells) or desirable chemicals (microbial electrosynthesis or electrolysis).(Nevin, Woodard, Franks, Summers, & Lovley, 2010) Many of these systems rely on the use of a small number of bacterial species that are naturally electrochemically active, severely limiting the choices of organisms, and relying on processes that are poorly understood.(Wang & Ren, 2013) This project intends to overcome these limitations by developing new biological engineering paradigms focusing on redox biochemistry. In particular, we will use engineered redox systems that can work across cell boundaries, allowing them to form an intermediary between electrodes and cells.
The project will also investigate the application of bipolar electrochemistry techniques to microbial electrochemical systems. Bipolar electrochemistry is a unique technique that eliminates the need for membrane separated, connected electrochemical cells.(Fosdick, Knust, Scida, & Crooks, 2013) This concept has not yet been applied to microbial electrochemical system design. In combination with the use of mediator compounds, this could allow the development of systems containing multiple segregated organisms that are electrically connected, without relying on the use of semi-permeable membranes, and possibly allowing both scale-up and scale-down of biological electrochemical system design.
Overall, we envision this electrochemical engineering as an alternative to the genetic engineering of metabolism, allowing more specificity and higher control over metabolic fluxes. Developing a well characterised electrochemical system for the inclusion of an organism creates the opportunity for the realisation of microbial electrochemical systems that are designed-for-purpose rather than relying on natural systems and processes (like biofilm formation), expanding the synthetic biology engineering toolbox. Other synthetic biology tools such as genetic manipulation may also be used within the project, for example by engineering organisms to express their own mediator compounds, engineering additional redox reactions to alter cellular redox ratios (e.g. (Vemuri, Eiteman, McEwen, Olsson, & Nielsen, 2007)) or engineering the organisms to be adherent to electrodes.
Microbial electrochemical systems show great promise for use in environmentally friendly processes, as waste products can be used for feedstocks to generate useful output.(Venkata Mohan, Mohanakrishna, Srikanth, & Sarma, 2008) However, further development will be required for both scale-up and scale-down of these systems if they are to see significant real-word use. The semiconductor design company ARM is interested in the scale-down side, for the development of micro-scale microbial fuel cells to be used in ultra-low power internet-of-things devices, and have agreed to provide support for the project.
The project fits within the EPSRC research areas of synthetic biology, fuel cell technology, and bioenergy. Furthermore, the project sits within the emerging field of bioelectronics, where interfacing of cells with electrical circuits is expanding from neuronal systems to other cell types and tissue. This is an emerging. interdisciplinary area that fits within the EPSRC themes of biomedical research and innovation.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/R512333/1 01/10/2017 30/09/2021
2299623 Studentship EP/R512333/1 01/10/2017 30/09/2021 Alan Pledger Reed