Carbon dioxide reduction by mixed and pure cultures in microbial electrosynthesis using an assembly of graphite felt and stainless steel as a cathode. (November 2015)

• Record Type: Journal Article
• Authors: Bajracharya, Suman; ter Heijne, Annemiek; Dominguez Benetton, Xochitl; Vanbroekhoven, Karolien; Buisman, Cees J.N.; Strik, David P.B.T.B.; Pant, Deepak
• Is Part Of: Bioresource technology. Volume 195(2015)
• Page Start: 14
• Page End: 24
• Publication Date: 2015-11
• Subjects: Microbial electrosynthesis -- CO2 reduction -- Biocathode -- Hydrogen evolution -- Bioproduction; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2015.05.081
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Stainless steel and graphite felt assembly as a CO2 reducing biocathode material. Higher acetate production rates from C. ljungdahlii with hydrogen evolution. CH4 production predominated from CO2 reduction by non-enriched mixed culture. H2 evolution appears to stimulate planktonic bacteria rather than cathodic-biofilm. Abstract: Carbon dioxide (CO2 ) reduction to multi-carbon compounds at the cathode using chemolithoautotrophs is an emerging application of microbial electrosynthesis (MES). In this study, CO2 reduction in MES was investigated at hydrogen evolving potentials, separately by a mixed culture and Clostridium ljungdahlii, using a graphite felt and stainless steel assembly as cathode. The mixed culture reactor produced acetate at the maximum rate of 1.3 mM d −1, along with methane and hydrogen at −1.1 V/Ag/AgCl . Over 160 days of run-time in four fed-batches, 26% of bicarbonate was converted to acetate between day 28 and 41, whereas in the late batches, methane production prevailed. Out of 45 days of run-time in the C. ljungdahlii reactor, 2.4 mM d −1 acetate production was achieved at −0.9 V/Ag/AgCl in Batch 1. Simultaneous product degradation occurred when the mixed culture was not selectively enriched. Hydrogen evolution is potentially the rapid way of transferring electrons to the biocatalysts for higher bioproduction rates.