Bio-electrical engineering: a promising frontier for synthetic biology

What do the following have in common? The production of methane gas from farm waste; toilets at a music festival, lit with LED lights; a bacterial biofilm that is on the brink of starvation. All of these involve microbes that are making use of bio-electrical processes. Though it is difficult to define the limits of what can be called bio-electrical, these processes are typically responding to or creating a current or voltage, with the electrical effects extending beyond the limit of an individual cell. In the examples above, current is flowing between organisms of different species or between an organism and an abiotic material, or voltage changes are being sensed and propagated across a colony of cells. Our appreciation of the extent of electrical phenomena in microbial biology has seen a recent revival, with studies revealing not just the variety of bioelectrical processes that exist but also defining the molecular mechanisms responsible. Now, we can begin to apply the approaches and techniques of synthetic biology. By re-engineering natural systems, we can hope to improve our understanding of how their components function and repurpose them for exciting biotechnological applications.