Directing Clostridium ljungdahlii fermentation products via hydrogen to carbon monoxide ratio in syngas

Journal Article · 04 April 2019 · Biomass and Bioenergy

DOI: https://doi.org/10.1016/j.biombioe.2019.03.011 · OSTI ID:1510418

Jack, Joshua ^[1]; Lo, Jonathan ^[1]; Maness, Pin-Ching ^[1]; Ren, Zhiyong Jason  ^[2]

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1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
2. Univ. of Colorado, Boulder, CO (United States); Princeton Univ., NJ (United States)

Clostridium ljungdahlii was grown on syngas of varying composition to investigate how syngas blends used in fermentation can be tailored toward desired product formation. Experiments were conducted with liquid batch cultures exposed to the same volume of gas with varying ratios of hydrogen to carbon monoxide (H₂/CO). Formation of acetate was favored by higher concentrations of hydrogen in the headspace. The maximum acetate concentration of 35.21 +/- 0.84 mM was obtained using an H₂/CO ratio of 2.0. Generation of more reduced metabolites was favored by greater carbon monoxide concentrations in the headspace. Maximum ethanol (7.53 +/- 0.58 mM) and 2,3-Butanediol (5.20 +/- 0.79 mM) concentrations were achieved under an H₂/CO ratio of 0.5. Linear relationships were obtained in that describe the effect of the syngas H₂/CO ratios on acetate, ethanol, and 2,3-BD formation, respectively.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: Renewable and Sustainable Energy Institute (RASEI); National Science Foundation (NSF)
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1510418
• Report Number(s): NREL/JA-2700-73838
• Journal Information: Biomass and Bioenergy, Vol. 124, Issue C; ISSN 0961-9534
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English