Characterization of the Weimberg Pathway in Caulobacter crescentus
| Autor: | Celina Tufvegren, Sara Jonsdottir Glaser, Henrik Almqvist, Lisa Wasserstrom, Gunnar Lidén |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Arabinose 030106 microbiology Plant Science Xylose Biochemistry Genetics and Molecular Biology (miscellaneous) 03 medical and health sciences chemistry.chemical_compound Caulobacter crescentus Extracellular arabinose lcsh:TP500-660 biology fungi physiological characterization xylose Substrate (chemistry) food and beverages biochemical phenomena metabolism and nutrition biology.organism_classification lcsh:Fermentation industries. Beverages. Alcohol Enzyme assay enzyme activity Weimberg pathway Biochemistry chemistry biology.protein bacteria Heterologous expression biological phenomena cell phenomena and immunity Bacteria Food Science |
| Zdroj: | Fermentation, Vol 4, Iss 2, p 44 (2018) Fermentation Volume 4 Issue 2 |
| ISSN: | 2311-5637 |
| Popis: | Caulobacter crescentus is a gram-negative bacterium that can utilize xylose as a substrate using the Weimberg pathway, which converts xylose to &alpha 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&minus 1, 0.05 h&minus 1, and 0.15 h&minus 1 respectively. Growth was found to be significantly inhibited at sugar concentration of 20 g L&minus 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 &alpha ketoglutarate&mdash up to a yield of 0.4 g g&minus 1&mdash 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 &alpha ketoglutarate. |
| Databáze: | OpenAIRE |
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