Metabolic and practical considerations on microbial electrosynthesis

The production of biofuels and biochemicals is highly electron intensive. To divert fermentative and respiratory pathways to the product of interest, additional electrons (i.e. reducing power) are often needed. Meanwhile, the past decade has seen the breakthrough of sustainable electricity sources such as solar and wind. Microbial electrosynthesis (MES) is at the nexus of both, as it uses electrical energy as source of reducing power for microorganisms. This review addresses the key opportunities and challenges for MES. While exciting as a concept, MES needs to overcome many biological, electrochemical, logistical and economic challenges. Particularly the latter is critical, as on a ‘per electron basis’ MES does not yet appear to deliver a substantial benefit relative to existing approaches.

Research highlights
► Microbial electrosynthesis concerns electricity driven bioproduction processes.
► We evaluate the challenges and opportunities for microbial electrosynthesis.
► There is no apparent direct financial benefit of electricity over sugar driven production.
► The low energy yield of homoacetogenesis will likely lead to low product yields.
► Land independent bioproduction is a key advantage of microbial electrosynthesis.