Biocatalytic reduction of short‐chain carboxylic acids into their corresponding alcohols with syngas fermentation
- 21 November 2012
- journal article
- research article
- Published by Wiley in Biotechnology & Bioengineering
- Vol. 110 (4), 1066-1077
- https://doi.org/10.1002/bit.24786
Abstract
Short-chain carboxylic acids generated by various mixed- or pure-culture fermentation processes have been considered valuable precursors for production of bioalcohols. While conversion of carboxylic acids into alcohols is routinely performed with catalytic hydrogenation or with strong chemical reducing agents, here, a biological conversion route was explored. The potential of carboxydotrophic bacteria, such as Clostridium ljungdahlii and Clostridium ragsdalei, as biocatalysts for conversion of short-chain carboxylic acids into alcohols, using syngas as a source of electrons and energy is demonstrated. Acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, and n-caproic acid were converted into their corresponding alcohols. Furthermore, biomass yields and fermentation stoichiometry from the experimental data were modeled to determine how much metabolic energy C. ljungdahlii generated during syngas fermentation. An ATP yield of 0.4–0.5 mol of ATP per mol CO consumed was calculated in the presence of hydrogen. The ratio of protons pumped across the cell membrane versus electrons transferred from ferredoxin to NAD+ via the Rnf complex is suggested to be 1.0. Based on these results, we provide suggestions how n-butyric acid to n-butanol conversion via syngas fermentation can be further improved. Biotechnol. Bioeng. 2013; 110: 1066–1077.Keywords
This publication has 32 references indexed in Scilit:
- Prolonged conversion of n‐butyrate to n‐butanol with Clostridium saccharoperbutylacetonicum in a two‐stage continuous culture with in‐situ product removalBiotechnology & Bioengineering, 2011
- Waste to bioproduct conversion with undefined mixed cultures: the carboxylate platformTrends in Biotechnology, 2010
- Biochemistry, evolution and physiological function of the Rnf complex, a novel ion-motive electron transport complex in prokaryotesCellular and Molecular Life Sciences, 2010
- ATP synthase: From sequence to ring size to the P/O ratioProceedings of the National Academy of Sciences, 2010
- Clostridium ljungdahlii represents a microbial production platform based on syngasProceedings of the National Academy of Sciences, 2010
- Biomass-derived syngas fermentation into biofuels: Opportunities and challengesBioresource Technology, 2010
- Cellulosic BiofuelsAnnual Review of Plant Biology, 2009
- Removal of fermentation inhibitors from alkaline peroxide pretreated and enzymatically hydrolyzed wheat straw: Production of butanol from hydrolysate using Clostridium beijerinckii in batch reactorsBiomass and Bioenergy, 2008
- Acetogenesis and the Wood–Ljungdahl pathway of CO2 fixationBiochimica et Biophysica Acta (BBA) - Proteins and Proteomics, 2008
- Structural Investigations of the Membrane-Embedded Rotor Ring of the F-ATPase from Clostridium paradoxumJournal of Bacteriology, 2006