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Updated: Sep 19, 2025

Characterizing Mediated Extracellular Electron Transfer in Lactic Acid Bacteria with a Three-Electrode, Two-Chamber Bioelectrochemical System
Published on: August 23, 2024
Synergy among multiple electron donors in electro-fermentation chain elongation: Accelerated directional electron
Dengfei Li1, Aijuan Zhou2, Jun Mei3
1Department of Water Supply and Drainage, Taiyuan University of Technology, Taiyuan 030024, China; Shanxi-Zheda Institute of Advanced Material and Chemical Engineering, Taiyuan 030000, China.
Abstract:
Electro-fermentation assisted chain elongation (EF_CE) effectively converts organic waste into medium-chain fatty acids (MCFAs), yet the regulatory mechanisms involving multiple electron donors (EDs) require elucidation. This study systematically explored the synergistic effects of ethanol and lactate as EDs on MCFA biosynthesis in EF_CE systems. The cross-niche microbial associations shaped by multiple EDs coupled with inoculation with caproate-synthesizing bacteria led to a 2.9-3.9-fold increase in caproate synthesis. Metagenomic analysis revealed that multiple EDs decreased the relative abundances of genes encoding Mut in the acrylate pathway, while increasing the relative abundances of genes encoding ascB in the Wood-Ljungdahl pathway, and ADH, kor and cdhA in ethanol and lactate oxidation pathways. These findings highlight the dual role of EDs synergy in directing MCFAs production and reshaping microbial networks, offering insights for improving organic waste/wastewater recycling.
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