Beyond the farm: making edible protein from CO2 via hybrid bioinorganic electrosynthesis

Mingyi Xu, Huihui Zhou, Rusen Zou, Xiaoyong Yang, Yanyan Su, Irini Angelidaki, Yifeng Zhang*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Climate change and food shortage are two of the defining challenges in the coming decades. Considering that conventional approaches for protein production may associate with negative environmental impacts and greenhouse gas emissions, alternative protein sources that rely on inexhaustible substrates/energy should be pursued. In this proof-of-concept study, we propose a two-stage bioinorganic electrosynthesis process that can first convert CO2 and excessive electricity into methane and then synthesize single-cell protein. With an external voltage of 3.5 V and a CO2 inflow rate of 50 mL·d−1, it was possible to produce methanotrophic biomass of 118.7 ± 9.2 mg·L−1 with an amino acids mass content of 54.6% ± 8.3%, resulting in nitrogen assimilation and CO2 conversion efficiency of 91.0% ± 1.3% and 71.0%. The applied voltages, CO2 inflow rates, and O2 supply were found to affect the process significantly. This process using renewable feedstocks was proved independent of conventional agriculture for protein production.

Original languageEnglish
JournalOne Earth
Volume4
Issue number6
Pages (from-to)868-878
ISSN0144-8595
DOIs
Publication statusPublished - 2021

Bibliographical note

Funding Information:
This work was supported by the Novo Nordisk Foundation (NNF16OC0021568, Denmark) and the Carlsberg Foundation Distinguished Fellowships (CF18-0084, Denmark). The authors would like to acknowledge the financial support from the China Scholarship Council (China) and the Otto M?nsted Fond (Denmark). The authors would like to thank Hector Gracia, Sinh Hy Nguyen, Mikael Emil Olsson, and Dan Zhao for the experimental assistance. M.X. and Y.Z. contributed to the conceptualization. M.X. and H.Z. designed the methodology and conducted the experiments. M.X. R.Z. X.Y. and S.Y. contributed to the resources and the visualization. Y.Z. and I.A. contributed to funding acquisition. M.X. wrote the original manuscript. Y.Z, I.A. and S.Y. commented on or edited the manuscript. The authors declare no competing interests.

Funding Information:
This work was supported by the Novo Nordisk Foundation ( NNF16OC0021568 , Denmark) and the Carlsberg Foundation Distinguished Fellowships ( CF18-0084 , Denmark). The authors would like to acknowledge the financial support from the China Scholarship Council (China) and the Otto Mønsted Fond (Denmark). The authors would like to thank Hector Gracia, Sinh Hy Nguyen, Mikael Emil Olsson, and Dan Zhao for the experimental assistance.

Publisher Copyright:
© 2021 Elsevier Inc.

Keywords

  • aerobic methane oxidation
  • aerobic methanotrophs
  • carbon capture and utilization
  • electromethanogensis
  • hydrogenotrophic methanogens
  • microbial electrosynthesis
  • power to protein
  • renewable electricity
  • single-cell protein

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