1 research outputs found
Long-term Operation of Microbial Electrosynthesis Systems Improves Acetate Production by Autotrophic Microbiomes
Microbial electrosynthesis
is the biocathode-driven production
of chemicals from CO<sub>2</sub> and has the promise to be a sustainable,
carbon-consuming technology. To date, microbial electrosynthesis of
acetate, the first step in order to generate liquid fuels from CO<sub>2</sub>, has been characterized by low rates and yields. To improve
performance, a previously established acetogenic biocathode was operated
in semi-batch mode at a poised potential of β590 mV vs SHE
for over 150 days beyond its initial development. Rates of acetate
production reached a maximum of 17.25 mM day<sup>β1</sup> (1.04
g L<sup>β1</sup> d<sup>β1</sup>) with accumulation to
175 mM (10.5 g L<sup>β1</sup>) over 20 days. Hydrogen was also
produced at high rates by the biocathode, reaching 100 mM d<sup>β1</sup> (0.2 g L<sup>β1</sup> d<sup>β1</sup>) and a total
accumulation of 1164 mM (2.4 g L<sup>β1</sup>) over 20 days.
Phylogenetic analysis of the active electrosynthetic microbiome revealed
a similar community structure to what was observed during an earlier
stage of development of the electroacetogenic microbiome. <i>Acetobacterium</i> spp. dominated the active microbial population
on the cathodes. Also prevalent were <i>Sulfurospirillum</i> spp. and an unclassified Rhodobacteraceae. Taken together, these
results demonstrate the stability, resilience, and improved performance
of electrosynthetic biocathodes following long-term operation. Furthermore,
sustained product formation at faster rates by a carbon-capturing
microbiome is a key milestone addressed in this study that advances
microbial electrosynthesis systems toward commercialization