Project description:In this study, disruption and overexpression of sigD were performed in Corynebacterium glutamicum and analyzed by transcriptome sequencing (RNA-seq) to understand the SigD regulon in C. glutamicum. For the effect of sigD overexpression, the relative abundance of mRNA was compared in WT(pVWEx1-sigD) without IPTG or with 50 M of IPTG. For the effect of sigD disruption, the abundance was compared between the sigD disrupted mutant and the wild type strain.
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:To identify genes regulated by SigD, transcriptome profiles between wild type strain and sigD mutant with pI486-sigD, in which sigD level is low compared to wild type strain, were analyzed.
Project description:To understrand the altered global gene expression levels in C. glutamicum wild type in presence of furfural, transcriptome profiling was performed.
Project description:(Coryno)mycolate is a α-branched, β-hydroxylated long-chain fatty acid specifically synthesized in bacteria in the suborder Corynebacterineae of the phylum Actinobacteria. It forms an outer membrane and functions as a permeability barrier conferring pathogenic mycobacteria to resistance to antibiotics. Whereas mycolate biosynthetic pathway has been intensively studied, the studies on the transcriptional regulation of genes involved in the pathway are limited. Here, we report that the previously uncharacterized extracytoplasmic function σ factor, σD, is a key regulator of the mycolate synthetic genes in Corynebacterium glutamicum in the suborder. Chromatin immunoprecipitation with microarray analysis detected σD-binding regions in the genome, establishing a consensus promoter sequence for σD recognition. The σD regulon comprises acyl-CoA carboxylase subunits, acyl-AMP ligase, polyketide synthase, and mycolyltransferases, all of which are involved in mycolate synthesis. Actually, deletion or overexpression of sigD encoding σD modified the amount of extractable mycolate. Immediately downstream of sigD, rsdA encoded anti-σD and was under the control of a σD-dependent promoter. Another σD regulon member, L,D-transpeptidase, conferred lysozyme resistance. Thus, σD modifies cell wall composition and enhances mycolate synthesis to provide resistance to environmental stress.
