iScience
Volume 23, Issue 12, 18 December 2020, 101794
Journal home page for iScience

Review
Sparking Anaerobic Digestion: Promoting Direct Interspecies Electron Transfer to Enhance Methane Production

https://doi.org/10.1016/j.isci.2020.101794Get rights and content
Under a Creative Commons license
open access

Anaerobic digestion was one of the first bioenergy strategies developed, yet the interactions of the microbial community that is responsible for the production of methane are still poorly understood. For example, it has only recently been recognized that the bacteria that oxidize organic waste components can forge electrical connections with methane-producing microbes through biologically produced, protein-based, conductive circuits. This direct interspecies electron transfer (DIET) is faster than interspecies electron exchange via diffusive electron carriers, such as H2. DIET is also more resilient to perturbations such as increases in organic load inputs or toxic compounds. However, with current digester practices DIET rarely predominates. Improvements in anaerobic digestion associated with the addition of electrically conductive materials have been attributed to increased DIET, but experimental verification has been lacking. This deficiency may soon be overcome with improved understanding of the diversity of microbes capable of DIET, which is leading to molecular tools for determining the extent of DIET. Here we review the microbiology of DIET, suggest molecular strategies for monitoring DIET in anaerobic digesters, and propose approaches for re-engineering digester design and practices to encourage DIET.

Subject Areas

Chemistry
Energy Resources
Biotechnology
Energy Materials

Cited by (0)