ABSTRACT: Comparative analysis of Corynebacterium glutamicum transcriptome in response to expression of Egfp under the change of dissolved oxygen in bioreactor
Project description:Purpose:dissolved oxygen (DO) level is an important factor that could significantly influence microorganisms’ growth, maintenance, metabolism and product yield.The goals of this study are to comparative analysis on Corynebacterium glutamicum transcriptome in response to expression of eGFP under the change of dissolved oxygen in bioreactor,find the critical pathways and genes.
Project description:Purpose: dissolved oxygen (DO) level is an important factor that could significantly influence microorganisms’ growth, maintenance, metabolism and product yield. The goals of this study are to do comparative analysis on Corynebacterium glutamicum transcriptome in response to the change of dissolved oxygen in bioreactor, find the critical pathways and genes.
Project description:The exploration of scale-down models to imitate the influence of large scale bioreactor inhomogeneities on cellular metabolism is a topic with increasing relevance. While gradients of substrates, pH, or dissolved oxygen are often investigated, oscillating CO2/HCO3- levels, a typical scenario in large industrial bioreactors, is rarely addressed. Hereby, we investigate the metabolic and transcriptional response in Corynebacterium glutamicum wild type as well as the impact on L-lysine production in a model strain exposed to pCO2 gradients of (75-315) mbar. A novel three-compartment cascade bioreactor system was developed and characterized that offers high flexibility for installing gradients and residence times to mimic industrial-relevant conditions, and provides the potential of accurate carbon balancing. The phenomenological analysis of cascade fermentations imposed to the pCO2 gradients at industry-relevant residence times of about 3.55 min did not significantly impair the process performance, with growth and product formation being similar to control conditions. However, transcriptional analysis disclosed up to 66 differentially expressed genes already after 3.55min under stimulus exposure, with the overall change in gene expression directly correlateable to the pCO2 gradient intensity and the residence time of the cells.
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:To identify genes which are differentially expressed in Corynebacterium glutamicum in the absence of copper, we performed DNA microarray analyses of cells cultivated under copper starvation conditions compared to copper sufficiency.
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 investigate the adaptation of Corynebacterium glutamicum to altering oxygen availabilities, we conceived a triple-phase fermentation process that describes a gradual reduction of dissolved oxygen depicting a shift from aerobiosis via microaerobiosis to anaerobiosis. The distinct process phases were clearly bordered by the bacteria’s physiologic response such as reduced growth rate, biomass substrate yield and altered yield of fermentation products. During the process, sequential samples were drawn at six points and analyzed via RNA-sequencing of Illumina TruSeq Stranded mRNA libaries sequenced paired end on an Illumina MiSeq system using 75 nt read length. We found transcriptional alterations of almost 50 % (1421 genes) of the entire protein coding genes and observed an upregulation of fermentative pathways, a rearrangement of respiration and mitigation of the basic cellular mechanisms such as transcription, translation and replication as a transient response related to the installed oxygen dependent process phases.
