Extracellular electron transfer in acetogenic bacteria and its application for conversion of carbon dioxide into organic compounds

Appl Microbiol Biotechnol. 2017 Aug;101(16):6301-6307. doi: 10.1007/s00253-017-8421-3. Epub 2017 Jul 26.

Abstract

Acetogenic bacteria (i.e., acetogens) produce acetate from CO2 during anaerobic chemoautotrophic growth. Because acetogens fix CO2 with high energy efficiency, they have been investigated as biocatalysts of CO2 conversion into valuable chemicals. Recent studies revealed that some acetogens are capable of extracellular electron transfer (EET), which enables electron exchange between microbial cells and extracellular solid materials. Thus, acetogens are promising candidates as biocatalysts in recently developed bioelectrochemical technologies, including microbial electrosynthesis (MES), in which useful chemicals are biologically produced from CO2 using electricity as the energy source. In microbial photoelectrosynthesis, a variant of MES technology, the conversion of CO2 into organic compounds is achieved using light as the sole energy source without an external power supply. In this mini-review, we introduce the general features of bioproduction and EET of acetogens and describe recent progress and future prospects of MES technologies based on the EET capability of acetogens.

Keywords: CO2fixation; acetogen; bioproduction; extracellular electron transfer; microbial electrosynthsis.

Publication types

  • Review

MeSH terms

  • Acetates / metabolism*
  • Bacteria / metabolism*
  • Biocatalysis
  • Carbon Dioxide / metabolism*
  • Electricity
  • Electron Transport
  • Organic Chemicals / metabolism*
  • Veillonellaceae / metabolism

Substances

  • Acetates
  • Organic Chemicals
  • Carbon Dioxide