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Phosphoketolase pathway dominates in Lactobacillus reuteri ATCC 55730 containing dual pathways for glycolysis

Årsköld, Emma LU ; Lohmeier-Vogel, Elke; Cao, Rong LU ; Roos, Stefan; Rådström, Peter LU and van Niel, Ed LU (2008) In Journal of Bacteriology 190(1). p.206-212
Abstract
Metabolic flux analysis indicated that the heterofermentative Lactobacillus reuteri strain ATCC 55730 uses both the Embden-Meyerhof pathway (EMP) and phosphoketolase pathway (PKP) when glucose or sucrose is converted into the three-carbon intermediate stage of glycolysis. In all cases studied, the main flux is through the PKP, while the EMP is used as a shunt. In the exponential growth phase, 70%, 73%, and 84% of the flux goes through the PKP in cells metabolizing (i) glucose plus fructose, (ii) glucose alone, and (iii) sucrose alone, respectively. Analysis of the genome of L. reuteri ATCC 55730 confirmed the presence of the genes for both pathways. Further evidence for the simultaneous operation of two central carbon metabolic pathways... (More)
Metabolic flux analysis indicated that the heterofermentative Lactobacillus reuteri strain ATCC 55730 uses both the Embden-Meyerhof pathway (EMP) and phosphoketolase pathway (PKP) when glucose or sucrose is converted into the three-carbon intermediate stage of glycolysis. In all cases studied, the main flux is through the PKP, while the EMP is used as a shunt. In the exponential growth phase, 70%, 73%, and 84% of the flux goes through the PKP in cells metabolizing (i) glucose plus fructose, (ii) glucose alone, and (iii) sucrose alone, respectively. Analysis of the genome of L. reuteri ATCC 55730 confirmed the presence of the genes for both pathways. Further evidence for the simultaneous operation of two central carbon metabolic pathways was found through the detection of fructose-1,6-bisphosphate aldolase, phosphofructokinase, and phosphoglucoisomerase activities and the presence of phosphorylated EMP and PKP intermediates using in vitro 31P NMR. The maximum specific growth rate and biomass yield obtained on glucose were twice as low as on sucrose. This was the result of low ATP levels being present in glucose-metabolizing cells, although the ATP production flux was as high as in sucrose-metabolizing cells due to a twofold increase of enzyme activities in both glycolytic pathways. Growth performance on glucose could be improved by adding fructose as an external electron acceptor, suggesting that the observed behavior is due to a redox imbalance causing energy starvation. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Bacteriology
volume
190
issue
1
pages
206 - 212
publisher
American Society for Microbiology
external identifiers
  • wos:000252080400019
  • scopus:37549020032
ISSN
0021-9193
DOI
10.1128/JB.01227-07
language
English
LU publication?
yes
id
f52b6152-71ca-4f0f-a89d-723b7165a8ed (old id 938395)
date added to LUP
2008-01-21 09:59:02
date last changed
2017-10-29 03:29:48
@article{f52b6152-71ca-4f0f-a89d-723b7165a8ed,
  abstract     = {Metabolic flux analysis indicated that the heterofermentative Lactobacillus reuteri strain ATCC 55730 uses both the Embden-Meyerhof pathway (EMP) and phosphoketolase pathway (PKP) when glucose or sucrose is converted into the three-carbon intermediate stage of glycolysis. In all cases studied, the main flux is through the PKP, while the EMP is used as a shunt. In the exponential growth phase, 70%, 73%, and 84% of the flux goes through the PKP in cells metabolizing (i) glucose plus fructose, (ii) glucose alone, and (iii) sucrose alone, respectively. Analysis of the genome of L. reuteri ATCC 55730 confirmed the presence of the genes for both pathways. Further evidence for the simultaneous operation of two central carbon metabolic pathways was found through the detection of fructose-1,6-bisphosphate aldolase, phosphofructokinase, and phosphoglucoisomerase activities and the presence of phosphorylated EMP and PKP intermediates using in vitro 31P NMR. The maximum specific growth rate and biomass yield obtained on glucose were twice as low as on sucrose. This was the result of low ATP levels being present in glucose-metabolizing cells, although the ATP production flux was as high as in sucrose-metabolizing cells due to a twofold increase of enzyme activities in both glycolytic pathways. Growth performance on glucose could be improved by adding fructose as an external electron acceptor, suggesting that the observed behavior is due to a redox imbalance causing energy starvation.},
  author       = {Årsköld, Emma and Lohmeier-Vogel, Elke and Cao, Rong and Roos, Stefan and Rådström, Peter and van Niel, Ed},
  issn         = {0021-9193},
  language     = {eng},
  number       = {1},
  pages        = {206--212},
  publisher    = {American Society for Microbiology},
  series       = {Journal of Bacteriology},
  title        = {Phosphoketolase pathway dominates in Lactobacillus reuteri ATCC 55730 containing dual pathways for glycolysis},
  url          = {http://dx.doi.org/10.1128/JB.01227-07},
  volume       = {190},
  year         = {2008},
}