Production of Endotoxin-Free Microbial Biomass for Food Applications by Gas Fermentation of Gram-Positive H2-Oxidizing Bacteria

Antti Nyyssölä, Leo Ojala, Mikko Wuokko, Gopal Peddinti, Anu Tamminen, Irina Tsitko, Emilia Nordlund, Michael Lienemann*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

20 Citations (Scopus)
298 Downloads (Pure)

Abstract

The production of edible microbial biomass in bioreactors is an attractive alternative to agriculture, which is a major consumer of fresh water, an emitter of greenhouse gases, and a cause of eutrophication. This study examines microbial food production by gas fermentation of two endotoxin-free Gram-positive H2-oxidizing autotrophic bacterial strains, Nocardioides nitrophenolicus KGS-27 and Rhodococcus opacus DSM 43205. The supply of the gaseous substrates H2 and O2 by in situ water electrolysis was investigated as an alternative to providing them from an external source. N. nitrophenolicus KGS-27 produced ≤9.9 ±2.0 mg of biomass L−1 h−1 and was not affected by in situ water electrolysis, which potentially produces growth-inhibiting reactive oxygen species. With R. opacus DSM 43205, in turn, electrolysis slowed growth considerably and resulted in a volumetric productivity of 2.6 ± 0.8 mg of biomass L−1 h−1, which was a quarter of what was obtained with the gases supplied externally. The macromolecular compositions of biomasses produced by the two cultivation modes using the two bacterial strains were rather similar containing approximately 33−37% protein, 28−56% carbohydrates, and 4−5% fatty acids of the cell dry weight. Relatively high protein concentrations and balanced amino acid profiles, comparable to those of casein and soy protein, were achieved with both strains.
Original languageEnglish
Pages (from-to)470-479
JournalACS Food Science & Technology
Volume1
Issue number3
DOIs
Publication statusPublished - 16 Apr 2021
MoE publication typeA1 Journal article-refereed

Funding

This work was supported by the Academy of Finland (MOPED 295883, Optobio 287011, and Research Fellowship Grant to 321723 to M.L.), Business Finland (Fermatra 908/31/2016), and the Technology Industries of Finland Centennial Foundation and the Jane and Aatos Erkko foundation (“Feed and food from carbon dioxide and electricity—research and piloting of the future protein production”).

Keywords

  • Knallgas bacteria
  • gas fermentation
  • electrolysis
  • single-cell protein
  • cellular agriculture

Fingerprint

Dive into the research topics of 'Production of Endotoxin-Free Microbial Biomass for Food Applications by Gas Fermentation of Gram-Positive H2-Oxidizing Bacteria'. Together they form a unique fingerprint.

Cite this