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. Overall design: Method: three batches of fermentation were conducted with different DO level separately (50%, 30%, 0%), and sampled on 20h of fermentation, the transcriptome of Corynebacterium glutamicum generated using Illumina hiseq 2000.
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. Overall design: Method:three batches of fermentation were conducted with different DO level separately (50%, 30%, 0%),and sampled on 20h of fermentation,the transcriptome of Corynebacterium glutamicum generated using Illumina hiseq 2500.
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 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.
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.
Project description:To identify genes which are differentially expressed in Corynebacterium glutamicum chassis C1 in comparison to the prophage free strain MB001, we performed DNA microarray analyses of C. glutamicum C1 against MB001. For this purpose RNA was isolated from cells cultivated in CGXII minimal medium with 2% glucose (w v-1) and harvested in the exponential growth phase at an OD600 of 5. Four biological replicates were performed. Overall design: Corynebacterium glutamicum chassis C1 in comparison to the prophage free strain MB001
Project description:Transcriptional profiling of Corynebacterium glutamicum cells comparing wild-type cells with cg0196 deletion mutant cells by site-specific gene deletion using the non-replicable integration vector. cg0196 is gene conding transcriptional regulator related carbon metabolism. Two-condition experiment, Wild vs. Δcg0196 cells. Independently grown and harvested. One replicate per array.
Project description:Lignocellulosic biomass is an abundant and renewable resource for biofuels and bio-based chemicals. Vanillin is one of the major phenolic inhibitors in biomass production using lignocellulose. To assess the response of Corynebacterium glutamicum to vanillin stress, a global transcriptional response analysis was performed by using microarray. Overall design: Samples were collected during the mid-logarithmic growth phase in minimal medium with added glucose (control sample 100mM) or vanillin as the sole carbon source (3mM), respectively. Two-condition experiment, glucose vs. vanillin. Biological replicates: 4 control replicates, 4 treatment replicates.