Corynebacterium glutamicum R
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ABSTRACT:
PROVIDER: PRJNA226573 | ENA |
REPOSITORIES: ENA
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Project description:Bacteria are known to cope with environmental changes by using alternative sigma factors binding to RNA polymerase core enzyme. Sigma factor is one of the targets to modify transcription regulation in bacteria and to influence production capacities. In this study, the effect of overexpressing all annotated sigma factor genes on C. glutamicum WT was assayed using an IPTG inducible plasmid system and different IPTG concentrations. It was revealed that growth was severely decreased when sigD or sigH were overexpressed with IPTG concentrations higher than 50 μM. Overexpression of sigH led to an obvious phenotypic change, a yellow-colored supernatant. HPLC analysis revealed that riboflavin was excreted to the medium when sigH was overexpressed and DNA Microarray analysis confirmed increased expression of riboflavin biosynthesis genes. In addition, genes for enzymes of the pentose phosphate pathway and for enzymes dependent on FMN, FAD or NADPH as cofactor were upregulated when sigH was overexpressed. To test if sigH overexpression can be exploited for production of riboflavin-derived FMN or FAD, the endogenous gene for bifunctional riboflavin kinase/FMN adenyltransferase was co-expressed with sigH from a plasmid. Balanced expression of sigH and ribF improved accumulation of riboflavin (19.8 ± 0.3 μM) and allowed for its conversion to FMN (33.1 ± 1.8 μM) in the supernatant. While a proof-of-concept was reached, conversion was not complete and titers were not high. This study revealed that inducible and gradable overexpression of sigma factor genes is an interesting approach to switch gene expression profiles and to discover untapped potential of bacteria for chemical production. Endogenous sigma factor gene, sigH, was overexpressed in C. glutamicum ATCC13032 from IPTG inducible vector, pEKEx3. Two different concentration of IPTG (10 μM and 15 μM) was used for induction of SigH expression.
2015-06-20 | E-GEOD-70017 | biostudies-arrayexpress
Project description:Chip-chip analysis of C. glutamicum SigD
| PRJNA397508 | ENA
Project description:Chip-chip analysis of C. glutamicum SigC
| PRJNA294084 | ENA
Project description:Chip-chip analysis of C. glutamicum GntR1
| PRJNA253045 | ENA
Project description:The extracytoplasmic function sigma factor SigH is responsible for heat and oxidative stress response in a biotechnologically -important bacterium Corynebacterium glutamicum. Due to the hierarchical nature of the regulatory network, it has not been possible to fully determine the SigH regulon by previous transcriptome analyses. Here, we determined the direct genome-wide targets of SigH were determined by ChIP-chip analysis using a deletion mutant of rshA, encoding an anti-sigma factor of SigH. Seventy-five SigH-dependent promoters, including 39 new ones, were identified. Firstly, SigH-dependent heat induction was confirmed for several of the new targets, including two genes (ilvD and lipA) encoding Fe-S cluster containing enzymes. Internal SigH-dependent promoters were found in operon-like gene clusters involved in the pentose phosphate pathway, and riboflavin biosynthesis, and Zn uptake. Accordingly, deletion of rshA resulted in hyperproduction of riboflavin probably due to the coordinated upregulation of these genes. A SigH-dependent promoter was also found upstream of znuC1 in the znuA1C1B1 operon encoding an ABC-type transporter for Zn uptake. Overexpression of znuC1B1 by deletion of rshA and by an IPTG-inducible promoter and similarly affected expression of Zn-responsive genes, indicating that SigH-dependent upregulation of part of the operon potentiates Zn uptake. probably through Zn overload, indicating new physiological roles of SigH. Furthermore, reporter assays demonstrated that rshA in the sigH-rshA operon was heat-inducible under the control of an internal SigH-dependent promoters, identified upstream of rshA within the sigH-rshA operon, while the sigH promoter was independent of SigH, suggesting negative autoregulation of SigH activity. Finally, a SigH-dependent promoter identified and upstream of sigA encoding the primary sigma factor , wereas highly heat-inducible, but much weaker than the known SigA-dependent one.. The promoter upstream of sigH was independent of SigH but showed weak heat-shock response. The known SigA-dependent sigA promoter was much stronger than the SigH-dependent one. Taken together with the fact that SigH also regulates sigB encoding the primary-like sigma factor, Tthese findings uncovered a complicated regulatory network of the sigma factors.
2014-11-25 | GSE52040 | GEO
Project description:Bacteria are known to cope with environmental changes by using alternative sigma factors binding to RNA polymerase core enzyme. Sigma factor is one of the targets to modify transcription regulation in bacteria and to influence production capacities. In this study, the effect of overexpressing all annotated sigma factor genes on C. glutamicum WT was assayed using an IPTG inducible plasmid system and different IPTG concentrations. It was revealed that growth was severely decreased when sigD or sigH were overexpressed with IPTG concentrations higher than 50 μM. Overexpression of sigH led to an obvious phenotypic change, a yellow-colored supernatant. HPLC analysis revealed that riboflavin was excreted to the medium when sigH was overexpressed and DNA Microarray analysis confirmed increased expression of riboflavin biosynthesis genes. In addition, genes for enzymes of the pentose phosphate pathway and for enzymes dependent on FMN, FAD or NADPH as cofactor were upregulated when sigH was overexpressed. To test if sigH overexpression can be exploited for production of riboflavin-derived FMN or FAD, the endogenous gene for bifunctional riboflavin kinase/FMN adenyltransferase was co-expressed with sigH from a plasmid. Balanced expression of sigH and ribF improved accumulation of riboflavin (19.8 ± 0.3 μM) and allowed for its conversion to FMN (33.1 ± 1.8 μM) in the supernatant. While a proof-of-concept was reached, conversion was not complete and titers were not high. This study revealed that inducible and gradable overexpression of sigma factor genes is an interesting approach to switch gene expression profiles and to discover untapped potential of bacteria for chemical production.
2015-06-20 | GSE70017 | GEO
Project description:To identify genes which are differentially expressed in Corynebacterium glutamicum in the cg2460 deletion strain, we performed DNA microarray analyses of C. glutamicum Δcg2460 compared to the WT.
2019-07-11 | GSE123974 | GEO
Project description:To identify genes which are differentially expressed in Corynebacterium glutamicum in the cg2699 deletion strain, we performed DNA microarray analyses of C. glutamicum Δcg2699 compared to the WT.
2018-08-28 | GSE117566 | GEO
Project description:Ciprofloxacin, an inhibitor of bacterial gyrase and topoisomerase IV, was shown to inhibit growth of C. glutamicum with concomitant excretion of L-glutamate. C. glutamicum strains overproducing L-lysine, L-arginine, L-ornithine, and putrescine, respectively, produced L-glutamate instead of the desired amino acid when exposed to ciprofloxacin. Even in the absence of the putative L-glutamate exporter gene yggB, ciprofloxacin effectively triggered L-glutamate production. When C. glutamicum wild type was cultivated under nitrogen-limiting conditions, 2-oxoglutarate rather than L-glutamate was produced as consequence of exposure to ciprofloxacin. Transcriptome analysis revealed that ciprofloxacin increased RNA levels of genes involved in DNA synthesis, repair and modification. Enzyme assays showed that 2-oxoglutarate dehydrogenase activity was decreased due to ciprofloxacin addition. Here, it was shown for the first time that production of L-glutamate by C. glutamicum may be triggered by an inhibitor of DNA synthesis and L-glutamate titers of up to 37 ± 1 mM and a substrate specific L-glutamate yield of 0.13 g/g were reached.
2016-01-26 | GSE77189 | GEO
Project description:Full proteoform characterization of recombinant porin A, porin B, porin C and porin H from Corynebacterium glutamicum
2017-02-02 | MSV000080529 | MassIVE