A model for electron transfer and cell energetics in bacterial cables

Biological systems are known to communicate by diffusing chemical signals in the surrounding medium. However, most of the recent literature has neglected the electron transfer mechanism occurring amongst living cells, and its role in cell-to-cell communication. While the importance of biological electron transfer is well-known for individual cells, the past decade has also brought about remarkable discoveries of multi-cellular microbial communities that transfer electrons between cells and across centimeter length scales, e.g., biofilms and multi-cellular bacterial cables. This paper develops a stochastic model that links electron transfer to the energetic state of the cell. The model is also extensible to larger communities, by allowing for electron exchange between neighboring cells. The proposed model is a first step towards the design of electron-based communication networks in microbial communities, which may co-exist with the more well-known communication strategies based on molecular diffusion, while benefiting from a much shorter signaling delay.