Project description:Purpose:C. beijerinckii DSM 6423 is the most cited natural IpOH producer. Improving the natural production of this strain through a targeted approach required a full sequencing and characterization of its genome, together with transcriptomic analyses of its own regulations.The goals of this study are then to evaluate the transcriptional profile (RNA-Seq) of C. beijerinckii DSM6423, a natural isopropanol producer, during a fermentation of glucose in controlled bioreactors. Methods : A RNA-Seq approach was chosen in order to have a timelapse study of DSM 6423 throughout the fermentation process. Three independent duplicate fermentations of DSM 6423 were carried out in bioreactors on three different weeks, showing good reproducibility. On each cultivation, five biomass samples were collected for RNA-Seq analyses.and DNA was eliminated after DNAse I treatment (AM1906, Invitrogen). The 15 resulting RNA samples were sequenced and analyzed using the previously reconstructed genome of DSM 6423. Results: Using a data analysis workflow (TAMARA) developed by the Genoscope platform of Evry, we were able to highlight the transcriptional regulation along the fermentation by calculating the transcription profiles of each gene, using the 3h sample as reference. Clustering was performed using CAST algorithm revealed 8 clusters containing 953 genes and corresponding to genes up-regulated at 6, 8, 11 or 24 hours and gene down-regulated at 6, 8, 11 or 24 hours. Conclusion : Such analyses were carried out in this study and provide useful data to better understand the genetic background and the physiological specificities of C. beijerinckii DSM6423 isopropanol producer. Notably, this work is the first omic study of a natural IBE producer. The data gathered needs time for proper exploitation, but a better understanding of the metabolic pathways and various genes involved opens the door for future targeted approaches.
Project description:This SuperSeries is composed of the following subset Series: GSE12358: Clostridium beijerinckii NCIMB 8052 wild-type fermentation time course GSE12359: Clostridium beijerinckii BA101 mutant fermentation time course Refer to individual Series
Project description:The fermentation culture of Clostridium beijerinckii mutant BA101 was monitored from exponential growth to stationary phase. During this period the culture underwent a shift from acidogenesis to solventogenesis. Acetone and butanol production was initiated with the onset of the solventogenic phase. Using DNA microarray changes in gene expression were examined during the transitional period. RNA samples were taken from Clostridium beijerinckii mutant BA101 fermentation culture at individual time points during the acidogenic phase and the solventogenic phase. The samples were used for microarray hybridization.
Project description:The fermentation culture of Clostridium beijerinckii mutant BA101 was monitored from exponential growth to stationary phase. During this period the culture underwent a shift from acidogenesis to solventogenesis. Acetone and butanol production was initiated with the onset of the solventogenic phase. Using DNA microarray changes in gene expression were examined during the transitional period.
Project description:Clostridium beijerinckii is an anaerobic strain and well known for acetone-ethanol-butanol (ABE) fermentation using carbohydrates derived from cellulose or starch. During ABE fermentation, various byproducts are formed, mainly including acids (acetate, butyrate and lactate) and gas (hydrogen and carbon dioxide). recently, we found that Clostridium beijerinckii is able to produce a new product that had never been reported before and tightly regulated by pH and nitrogen source.
Project description:Furfural is the prevalent microbial inhibitor generated during pretreatment and hydrolysis of lignocellulosic biomass to monomeric sugars, but the molecular response of Clostridium beijerinckii NCIMB 8052 to this compound is unknown. To discern the effect of furfural on C. beijerinckii and to gain insights into the molecular mechanisms of action and detoxification, we studied the physiological changes of furfural-stressed cultures during acetone-butanol-ethanol (ABE) fermentation, and profiled differentially expressed genes by genome-wide transcriptional analysis. C. beijerinckii exposed to furfural stress during the acidogenic growth phase produced 13% more ABE than the unstressed control. The growth and ABE by C. beijerinckii ceased following exposure to furfural stress during the solventogenic growth phase. By comparing gene expression of furfural-stressed cultures to that of the unstressed control, at both the acidogenic and solventogenic phases, we ascertained that furfural induces expression of several genes including those that code for heat shock proteins, redox enzymes and cofactor associated proteins, and ATP-binding cassette transporters, and represses genes belonging to the phosphotransferase system, two-component system, chemotaxis and cell motility. Based on these results, we discuss the underpinning for furfural-mediated change in ABE fermentation by the solventogenic Clostridium species.
Project description:The Clostridium beijerinckii NCIMB 8052 wild-type culture was monitored from exponential growth to stationary phase. During this period the culture underwent a shift from acidogenesis to solventogenesis. Acetone and butanol production was initiated with the onset of the solventogenic phase. Using DNA microarray changes in gene expression were examined during the transitional period. RNA samples were taken from Clostridium beijerinckii NCIMB 8052 wild-type fermentation culture at individual time points during the acidogenic phase and the solventogenic phase. The samples were used for microarray hybridization.
Project description:Solventogenic Clostridium species ferment carbohydrates to acetone, butanol and ethanol which are well-known next-generation biofuels. However, repeated subculture of or continuous fermentation by Clostridium often decreases and eventually terminates the solvent production and spore formation, which is a process called strain degeneration. Supplementation of CaCO3 to fermentation medium could partially recover metabolism of degenerated strain by more than 50% increase of cell growth and solvent production. The transcriptome profile of Clostridium beijerinckii NCIMB 8052 (DG-8052) and its response to CaCO3 treatment were analysed by microarray. Since fermentation by C. beijerinckii NCIMB 8052 is a biphasic process, gene expressions of two fermentations were compared at each stage, i.e. 12h and 24h fermentation time representing acidogenic phase and solventogenic phase, respectively. This study examined expression of 5168 genes capturing 98.6% of the C. beijerinckii NCIMB 8052 genome. With the addition of CaCO3, DG-8052 had 565 and 916 genes significantly up-regulated at acidogenic phase and solventogenic phase, respectively. According to the enrichment analysis of pathway and Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, these genes were significantly overrepresented in cellular functions such as Amino acid transport and metabolism, organic acid biosynthetic process, bacteria chemotaxis and defense mechanisms. On the other hand, there were 704 and 1044 genes significantly down-regulated at acidogenic phase and solventogenic phase, respectively. These repressed genes were mainly enriched in functions such as ion transmembrane transport, ATP synthesis, oxidative phosphorylation.
Project description:This experiment aim was to characterize the catabolism of L-rhamnose of Clostridium beijerinckii DSM 6423 by transcriptomic analysis, generating new insights and knowledge on utilization of L-rhamnose for production of chemicals, including Isopropanol, Butanol, Ethanol (IBE) and 1,2-propandiol. These analysis on cultures grown on L-rhamnose compared to D-glucose grown cultures showed upregulation of the L-rhamnose-related clusters and genes, and lower expression of the solventogenic genes, which was reflected in the products formed.
Project description:Furfural is the prevalent microbial inhibitor generated during pretreatment and hydrolysis of lignocellulosic biomass to monomeric sugars, but the molecular response of Clostridium beijerinckii NCIMB 8052 to this compound is unknown. To discern the effect of furfural on C. beijerinckii and to gain insights into the molecular mechanisms of action and detoxification, we studied the physiological changes of furfural-stressed cultures during acetone-butanol-ethanol (ABE) fermentation, and profiled differentially expressed genes by genome-wide transcriptional analysis. C. beijerinckii exposed to furfural stress during the acidogenic growth phase produced 13% more ABE than the unstressed control. The growth and ABE by C. beijerinckii ceased following exposure to furfural stress during the solventogenic growth phase. By comparing gene expression of furfural-stressed cultures to that of the unstressed control, at both the acidogenic and solventogenic phases, we ascertained that furfural induces expression of several genes including those that code for heat shock proteins, redox enzymes and cofactor associated proteins, and ATP-binding cassette transporters, and represses genes belonging to the phosphotransferase system, two-component system, chemotaxis and cell motility. Based on these results, we discuss the underpinning for furfural-mediated change in ABE fermentation by the solventogenic Clostridium species. C. beijerinckii 8052 pre-culture was incubated anaerobically to attain acidogenic or solventogenic growth phase. The culture was then subdivided into two bottles. One bottle was challenged with furfural and the other bottle was left unchallenged. After 3 h growth, C. beijerinckii 8052 samples were collected, during which the original concentration of furfural in the growth medium was reduced to more than half. Total RNA was isolated, purified, converted to enriched mRNA, and dye-coupled (Alexa Fluor 555) complementary cRNA. This was followed by hybridization and microarray data analysis.