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| Status |
Public on Feb 13, 2013 |
| Title |
Glucose catabolism via a partially cyclic pentose phosphate pathway in Gluconobacter oxydans 621H: a combined fluxomics and transcriptomics analysis |
| Organism |
Gluconobacter oxydans 621H |
| Experiment type |
Expression profiling by array
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| Summary |
In this study, the distribution and regulation of periplasmic and cytoplasmic carbon fluxes in Gluconobacter oxydans 621H with glucose were studied by 13C-based metabolic flux analysis (13C-MFA) in combination with transcriptomics and enzyme assays. For 13C-MFA, cells were cultivated with specifically 13C-labeled glucose and intracellular metabolites were analyzed for their labeling pattern by LC-MS. In growth phase I, 90% of the glucose was oxidized periplasmatically to gluconate and partially further oxidized to 2-ketogluconate. Of the glucose taken up by the cells, 9% was phosphorylated to glucose 6-phosphate, whereas 91% was oxidized by cytoplasmic glucose dehydrogenase to gluconate. Additional gluconate was taken up into the cells by transport. Of the cytoplasmic gluconate, 70% was oxidized to 5-ketogluconate and 30% was phosphorylated to 6-phosphogluconate. In growth phase II, 87% of gluconate was oxidized to 2-ketogluconate in the periplasm and 13% was taken up by the cells and almost completely converted to 6-phosphogluconate. Since G. oxydans lacks phosphofructokinase, glucose 6-phosphate can only be metabolized via the oxidative pentose phosphate pathway (PPP) or the Entner-Doudoroff pathway (EDP). 13C-MFA showed that 6-phosphogluconate is catabolized primarily via the oxidative PPP in both phase I and II (62% and 93%) and demonstrated a cyclic carbon flux through the oxidative PPP. The transcriptome comparison revealed an increased expression of PPP genes in growth phase II, which was supported by enzyme activity measurements and correlated with the increased PPP flux in phase II. Moreover, genes possibly related to a general stress response displayed increased expression in growth phase II.
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| Overall design |
The transcriptome comparisons of G. oxydans growth phase II vs. growth phase I were repeated independently three times in biological replicates resulting in 3 hybridizations as termed by sample 1 to 3.
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| Contributor(s) |
Hanke T, Nöh K, Noack S, Polen T, Bringer S, Sahm H, Wiechert W, Bott M |
| Citation(s) |
23377928 |
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| Submission date |
Nov 12, 2012 |
| Last update date |
Feb 13, 2013 |
| Contact name |
Tino Polen |
| E-mail(s) |
t.polen@fz-juelich.de
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| Organization name |
Forschungszentrum Jülich GmbH
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| Department |
IBG-1: Biotechnology
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| Street address |
Leo Brandt Str.
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| City |
Juelich |
| State/province |
NRW |
| ZIP/Postal code |
52425 |
| Country |
Germany |
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| Platforms (1) |
| GPL15741 |
FZ_IBG-1_Goxydans_10K_Ver1 array |
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| Samples (3) |
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| Relations |
| BioProject |
PRJNA179373 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE42223.txt.gz |
54.5 Kb |
(ftp)(http) |
TXT |
| GSE42223_RAW.tar |
2.5 Mb |
(http)(custom) |
TAR (of GPR) |
| Processed data included within Sample table |
| Processed data are available on Series record |
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