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Characterization of the Weimberg Pathway in Caulobacter crescentus

Almqvist, Henrik LU ; Jonsdottir Glaser, Sara; Tufvegren, Celina LU ; Wasserstrom, Lisa LU and Lidén, Gunnar LU (2018) In Fermentation MDPI 4(2). p.44-44
Abstract
Caulobacter crescentus is a gram-negative bacterium that can utilize xylose as a substrate using the Weimberg pathway, which converts xylose to α-ketoglutarate in five steps without carbon loss. This is an interesting pathway for heterologous expression in other organisms in order to enable xylose utilization in biorefinery processes. C. crescentus was grown on xylose, arabinose and glucose, and maximum specific growth rates determined for the three substrates were 0.11 h−1, 0.05 h−1, and 0.15 h−1 respectively. Growth was found to be significantly inhibited at sugar concentration of 20 g L−1, shown primarily by an increased lag phase. Enzyme activity assays showed that the Weimberg pathway was active in cells grown, not only on xylose but... (More)
Caulobacter crescentus is a gram-negative bacterium that can utilize xylose as a substrate using the Weimberg pathway, which converts xylose to α-ketoglutarate in five steps without carbon loss. This is an interesting pathway for heterologous expression in other organisms in order to enable xylose utilization in biorefinery processes. C. crescentus was grown on xylose, arabinose and glucose, and maximum specific growth rates determined for the three substrates were 0.11 h−1, 0.05 h−1, and 0.15 h−1 respectively. Growth was found to be significantly inhibited at sugar concentration of 20 g L−1, shown primarily by an increased lag phase. Enzyme activity assays showed that the Weimberg pathway was active in cells grown, not only on xylose but also on arabinose. No activity was found for growth on glucose. Furthermore, substantial amounts of α-ketoglutarate—up to a yield of 0.4 g g−1—was excreted during growth on xylose, but no other extracellular intermediates in the Weimberg pathway were detected during growth on xylose. Apparently, C. crescentus is not well adapted for efficient growth on high xylose levels, and responds by an extended lag phase and secretion of α-ketoglutarate. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Caulobacter crescentus, Weimberg pathway, xylose, arabinose, physiological characterization, enzyme activity
in
Fermentation MDPI
volume
4
issue
2
pages
11 pages
ISSN
2311-5637
DOI
10.3390/fermentation4020044
language
English
LU publication?
yes
id
9a579f65-0d82-4bb5-9e92-68412970d109
date added to LUP
2018-06-18 09:46:36
date last changed
2018-06-19 16:21:27
@article{9a579f65-0d82-4bb5-9e92-68412970d109,
  abstract     = {Caulobacter crescentus is a gram-negative bacterium that can utilize xylose as a substrate using the Weimberg pathway, which converts xylose to α-ketoglutarate in five steps without carbon loss. This is an interesting pathway for heterologous expression in other organisms in order to enable xylose utilization in biorefinery processes. C. crescentus was grown on xylose, arabinose and glucose, and maximum specific growth rates determined for the three substrates were 0.11 h−1, 0.05 h−1, and 0.15 h−1 respectively. Growth was found to be significantly inhibited at sugar concentration of 20 g L−1, shown primarily by an increased lag phase. Enzyme activity assays showed that the Weimberg pathway was active in cells grown, not only on xylose but also on arabinose. No activity was found for growth on glucose. Furthermore, substantial amounts of α-ketoglutarate—up to a yield of 0.4 g g−1—was excreted during growth on xylose, but no other extracellular intermediates in the Weimberg pathway were detected during growth on xylose. Apparently, C. crescentus is not well adapted for efficient growth on high xylose levels, and responds by an extended lag phase and secretion of α-ketoglutarate.},
  author       = {Almqvist, Henrik and Jonsdottir Glaser, Sara and Tufvegren, Celina and Wasserstrom, Lisa and Lidén, Gunnar},
  issn         = {2311-5637},
  keyword      = {Caulobacter crescentus,Weimberg pathway,xylose,arabinose,physiological characterization,enzyme activity},
  language     = {eng},
  month        = {06},
  number       = {2},
  pages        = {44--44},
  series       = {Fermentation MDPI},
  title        = {Characterization of the Weimberg Pathway in Caulobacter crescentus},
  url          = {http://dx.doi.org/10.3390/fermentation4020044},
  volume       = {4},
  year         = {2018},
}