Long-term operation of microbial electrosynthesis cell reducing CO2 to multi-carbon chemicals with a mixed culture avoiding methanogenesis

Suman Bajracharya, Rustiana Yuliasni, Karolien Vanbroekhoven, Cees J.N. Buisman, David P.B.T.B. Strik*, Deepak Pant

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

71 Citations (Scopus)

Abstract

In microbial electrosynthesis (MES), CO2 can be reduced preferably to multi-carbon chemicals by a biocathode-based process which uses electrochemically active bacteria as catalysts. A mixed anaerobic consortium from biological origin typically produces methane from CO2 reduction which circumvents production of multi-carbon compounds. This study aimed to develop a stable and robust CO2 reducing biocathode from a mixed culture inoculum avoiding the methane generation. An effective approach was demonstrated based on (i) an enrichment procedure involving inoculum pre-treatment and several culture transfers in H2:CO2 media, (ii) a transfer from heterotrophic to autotrophic growth and (iii) a sequential batch operation. Biomass growth and gradual acclimation to CO2 electro-reduction accomplished a maximum acetate production rate of 400 mg Lcatholyte − 1 d− 1 at − 1 V (vs. Ag/AgCl). Methane was never detected in more than 300 days of operation. Accumulation of acetate up to 7–10 g L− 1 was repeatedly attained by supplying (80:20) CO2:N2 mixture at − 0.9 to − 1 V (vs. Ag/AgCl). In addition, ethanol and butyrate were also produced from CO2 reduction. Thus, a robust CO2 reducing biocathode can be developed from a mixed culture avoiding methane generation by adopting the specific culture enrichment and operation procedures without the direct addition of chemical inhibitor.

Original languageEnglish
Pages (from-to)26-34
JournalBioelectrochemistry
Volume113
DOIs
Publication statusPublished - 2017

Keywords

  • Autotrophic bioproduction
  • Biocathode
  • CO reduction
  • Microbial electrosynthesis
  • Wood-Ljungdahl pathway

Fingerprint Dive into the research topics of 'Long-term operation of microbial electrosynthesis cell reducing CO<sub>2</sub> to multi-carbon chemicals with a mixed culture avoiding methanogenesis'. Together they form a unique fingerprint.

  • Cite this