Biocatalytic reduction of short-chain carboxylic acids into their corresponding alcohols with syngas fermentation

Perez, JM; Richter, H; Loftus, SE; Angenent, LT

HERO ID

1454468

Reference Type

Journal Article

Year

2013

Language

English

PMID

23172270

HERO ID 1454468
In Press No
Year 2013
Title Biocatalytic reduction of short-chain carboxylic acids into their corresponding alcohols with syngas fermentation
Authors Perez, JM; Richter, H; Loftus, SE; Angenent, LT
Journal Biotechnology and Bioengineering
Volume 110
Issue 4
Page Numbers 1066-1077
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. © 2012 Wiley Periodicals, Inc.
Doi 10.1002/bit.24786
Pmid 23172270
Wosid WOS:000315360100007
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English