Bacterial synthesis gas (syngas) fermentation

Abstract

Acetogenic bacteria employing the Wood–Ljungdahl pathway can be used as biocatalysts in syngas fermentation for the production of biofuels such as ethanol or butanol as well as biocommodities such as acetate, lactate, butyrate, 2,3 butanediol, and acetone. The potential of such processes can be projected by the global syngas output, which was 70,817 megawatts thermal in 2010 and is expected to increase up to 72% in 2016. To date, different acetogens are used as commercial production strains for industrial syngas fermentations in pilot or demonstration plants (Coskata, INEOS Bio, LanzaTech) and first commercial units are expected to launch operation in the near future (INEOS Bio, LanzaTech). Considerations on potential yields are quite promising for fermentative production. New methods for metabolic engineering were established to construct novel recombinant acetogenic biocatalysts. Synthetic biology will certainly play a major role in constructing strains for commercial operations. This way, a cheap and abundant carbon source most probably replace, processes based on crude oil or sugar in the near future.

Keywords:

• acetogenic bacteria
• acetogens
• carbon dioxide
• carbon monoxide
• syngas

Funding

Work in the author's laboratory has been and is supported by Grants from the BMBF GenoMik Plus (Competence Network Göttingen), Bio-Industrie 2021, ‘Chemische Prozesse und stoffliche Nutzung von CO₂’ programs, the BMELV program ‘Nachwachsende Rohstoffe’, and Evonik Industries AG.