Project description:In this study, we analyzed the regulation of ƴ-aminobutyrate (GABA) utilization in Corynebacterium glutamicum by the PucR-type transcriptional regulator GabR and by alternative nitrogen and carbon sources.
Project description:Muconic acid production from engineered Corynebacterium glutamicum. Gene expression analysis in the pathway redesigned Corynebacterium glutamicum
Project description:For the establishment of synthetic microbial communities comprising complementary auxotrophic strains, transport processes for common goods are extremely important. Most auxotrophic strains reach wild type level growth with external supplementation of the required metabolite. One exception was the tryptophan auxotrophic strain Corynebacterium glutamicum ΔTRP ΔtrpP, which grew about 35% slower than the wild type in supplemented minimal medium. Corynebacterium glutamicum ΔTRP ΔtrpP lacks the whole tryptophan biosynthesis cluster (TRP) as well as the putative tryptophan transporter TrpP. We wanted to explore the role of TrpP in tryptophan transport or synthesis and to unravel the cause for the growth limitation of the auxotrophic strain.
Project description:The response regulator HrrA belonging to the HrrSA two-component system (previously named CgtSR11) is known to be repressed by the global iron-dependent regulator DtxR in Corynebacterium glutamicum. Sequence analysis indicated an involvement of the HrrSA system in heme-dependent gene expression. Growth experiments revealed that the non-pathogenic soil bacterium C. glutamicum is able to use hemin or hemoglobin as sole iron source. In DNA microarray analyses a putative operon encoding the hemin-binding protein HtaA and the putative hemin ABC transporter HmuTUV showed a strong upregulation in heme-grown cells. Deletion of the hmu operon clearly affects heme utilization, but does not completely abolish growth on heme or hemoglobin. As a central part of this study, we investigated the regulon of the response regulator HrrA via comparative transcriptome analysis of a hrrA deletion mutant and C. glutamicum wild type in combination with DNA-protein interaction studies with purified HrrA protein. Our data provide evidence for a heme-dependent transcriptional activation of heme oxygenase (hmuO), an enzyme involved in the utilization of heme as iron source. Besides hmuO, HrrA was shown to activate the expression of heme-containing components of the respiratory chain, namely ctaD and the ctaE-qcrCAB operon encoding subunits I and III of cytochrome aa3 oxidase and three subunits of the cytochrome bc1 complex. Furthermore, HrrA represses almost all genes involved in heme biosynthesis, including glutamyl-tRNA reductase (hemA), uroporphyrinogen decarboxylase (hemE), and ferrochelatase (hemH). Thus, our data clearly emphasize a central role of the HrrSA system in the control of heme homeostasis in C. glutamicum.
Project description:Metabolically engineered Corynebacterium glutamicum strains were constructed for the enhanced production of L-arginine, and their gene expression profiles were investigated
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.
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.
Project description:Metabolically engineered Corynebacterium glutamicum strains were constructed for the enhanced production of L-arginine, and their gene expression profiles were investigated Gene expression profiles of two C. glutamicum strains AR2 and AR6 were examined for the 3043 genes twice.
