TY - JOUR
T1 - Genetic manipulation of butyrate formation pathways in Clostridium butyricum
AU - Cai, Guiqin
AU - Jin, Bo
AU - Saint, Chris
AU - Monis, Paul
PY - 2011/9/20
Y1 - 2011/9/20
N2 - Clostridium butyricum is one of the commonly used species for fermentative hydrogen production. While producing H
2, it can produce acids (lactic, acetic and butyric acids) and CO
2, as well as a small amount of ethanol. It has been proposed that elimination of competing pathways, such as the butyrate formation pathway, should increase H
2 yields in Clostridium species. However, the application of this strategy has been hindered by the unavailability of genetic tools for these organisms. In this study, we successfully transferred a plasmid (pMTL007) to C. butyricum by inter-specific conjugation with Escherichia coli and disrupted hbd, the gene encoding β-hydroxybutyryl-CoA dehydrogenase in C. butyricum. Fermentation data showed that inactivation of hbd in C. butyricum eliminated the butyrate formation pathway, resulting in a significant increase in ethanol production and an obvious decrease in H
2 yield compared with the wild type strain. However, under low partial pressure of H
2, the hbd-deficient strain showed increased H
2 production with the simultaneous decrease of ethanol production, indicating that H
2 production by C. butyricum may compete for NADH with the ethanol formation pathway. Together with the discovery of a potential bifurcating hydrogenase, this study extends our understanding of the mechanism of H
2 production by C. butyricum.
AB - Clostridium butyricum is one of the commonly used species for fermentative hydrogen production. While producing H
2, it can produce acids (lactic, acetic and butyric acids) and CO
2, as well as a small amount of ethanol. It has been proposed that elimination of competing pathways, such as the butyrate formation pathway, should increase H
2 yields in Clostridium species. However, the application of this strategy has been hindered by the unavailability of genetic tools for these organisms. In this study, we successfully transferred a plasmid (pMTL007) to C. butyricum by inter-specific conjugation with Escherichia coli and disrupted hbd, the gene encoding β-hydroxybutyryl-CoA dehydrogenase in C. butyricum. Fermentation data showed that inactivation of hbd in C. butyricum eliminated the butyrate formation pathway, resulting in a significant increase in ethanol production and an obvious decrease in H
2 yield compared with the wild type strain. However, under low partial pressure of H
2, the hbd-deficient strain showed increased H
2 production with the simultaneous decrease of ethanol production, indicating that H
2 production by C. butyricum may compete for NADH with the ethanol formation pathway. Together with the discovery of a potential bifurcating hydrogenase, this study extends our understanding of the mechanism of H
2 production by C. butyricum.
KW - Bifurcating hydrogenase
KW - Conjugation
KW - Hbd
KW - Hydrogen production
KW - Intron integration
UR - http://www.scopus.com/inward/record.url?scp=80052364547&partnerID=8YFLogxK
U2 - 10.1016/j.jbiotec.2011.07.004
DO - 10.1016/j.jbiotec.2011.07.004
M3 - Article
VL - 155
SP - 269
EP - 274
JO - Journal of Biotechnology
JF - Journal of Biotechnology
SN - 0168-1656
IS - 3
ER -