Microbial Electron Transfer Networks: From Single Cells to Ecosystems

Electrons play a central role in biological energy acquisition in individual cells, populations, and ecosystems. The energy released from electron flow provides fuel for biological growth and evolution, through fermentation, anaerobic and aerobic respiratory chains, and chemosynthetic and photosynthetic systems. Electron transfer occurs across scales: between neighboring cells, through communities, and in ecosystems. Across these scales, what limits electron flow also limits the amount and types of organisms that prosper in a given environment. Electron flow is facilitated by redox-active soluble molecules of carbon, hydrogen, oxygen, nitrogen, sulfur, and iron, or via a number of mechanisms associated with direct interspecies electron transfer. Redox reactions involving these elements form the basis of the associated geochemical cycles on Earth, affecting redox conditions not only in the biosphere but also in the atmosphere and lithosphere.

The aim of this collection is to bring together recent research in the area of electron transfer as it occurs through various mechanisms and at multiple scales in microbial systems. Understanding “electron transfer networks” may broaden our understanding of the processes governing electron flow across scales and how these connect to biological growth and evolution, and are also connected to geochemical cycling at the planetary scale.


This Research Topic welcomes contributions that can help identify electron transfer networks at multiple levels, including within individual cells, populations and communities, and ecosystems, occurring through carbon, hydrogen, oxygen, nitrogen, sulfur, and iron, or direct interspecies interaction. New understandings of electron exchange between cells and non-cellular material are also welcomed. This topic covers biochemical, physiological, ecological, evolutionary, and theoretical studies of aquatic, terrestrial, marine, and thermophilic natural environments as well as artificial environments of various treatments and model systems. Not being limited to contemporary biology, we also welcome contributions concerning electron transfer networks that may have facilitated the origin of metabolism on Earth, and also those that exist on other planets.