Medium-chain fatty acid production via microbial electrosynthesis: Mechanisms, progress, and prospects

Abstract

Microbial electrosynthesis (MES) offers a sustainable bioelectrochemical platform for converting renewable electricity and carbon sources, particularly carbon dioxide, into value-added chemicals. Medium-chain fatty acids (MCFAs, C6–C12) are of growing industrial interest due to their versatile applications and potential for sustainable production independent of fossil resources. This review critically examines the biochemical pathways and electrochemical principles underlying MCFA synthesis in MES systems. It also evaluates key system components, including microbial catalysts (e.g., Clostridium, Eubacterium), advanced electrode materials, and innovative reactor designs such as flow-through and fluidized bed configurations. Performance benchmarks, including production rates, titers, selectivity, and energy efficiencies, are summarized to assess technological progress. Major challenges related to electron transfer limitations, competing biological pathways, mass transfer constraints, and economic scalability are discussed. Finally, this review outlines future research directions and highlights how interdisciplinary advancements in reactor engineering, metabolic optimization, and system integration can accelerate the transition of MES from laboratory studies to industrial-scale sustainable bioproduction.