Project description:Clostridium acetobutylicum is a typical bacterium of major importance to industrial butanol production. In order to dissect the regulatory network pertaining to the industrial application of this bacterium, catabolite control protein A (CcpA) was investigated for its global function by DNA microarray.It showed that CcpA of C. acetobutylicum controls hundreds of genes, not only carbon metabolism, but also solvent production and sporulation in the life cycle.The results here demonstrated that CcpA is an important pleiotropic regulator related to some specific physiological and biochemical process in butanol-producing C. acetobutylicum.
Project description:In this study the transcriptional behavior of the natural solvent producing bacterium Clostridium acetobutylicum was investigated following n-butanol stress using DNA microarray analysis. Therefore, a phosphate-limited chemostat culture was established and n-butanol stress (0.9%) was added to acidogenic cells at pH 5.7.
Project description:In this study the transcriptional behavior of the natural solvent producing bacterium Clostridium acetobutylicum was investigated following n butanol stress using DNA microarray analysis. Therefore, a phosphate-limited chemostat culture was established and n-butanol stress (0.9%) was added to acidogenic cells at pH 5.7.
Project description:Clostridium acetobutylicum is a typical bacterium of major importance to industrial butanol production. In order to dissect the regulatory network pertaining to the industrial application of this bacterium, catabolite control protein A (CcpA) was investigated for its global function by DNA microarray.It showed that CcpA of C. acetobutylicum controls hundreds of genes, not only carbon metabolism, but also solvent production and sporulation in the life cycle.The results here demonstrated that CcpA is an important pleiotropic regulator related to some specific physiological and biochemical process in butanol-producing C. acetobutylicum. In order to enable a global understanding of the regulatory roles of CcpA when fermenting mixed sugars, which is of great significance in utilization of lignocellulosic hydrolysates, D-glucose plus D-xylose were used as the carbon sources in fermentation for microarray analysis. Microarray analysis was performed at four time points:the time point M and L were chosen both in acidogenic phase, while the time point T and S were chosen in shift phase (from acidogenesis to solventogenesis) and solventogenic phase, respectively.One-color microarray assays were performed.Raw data were normalized by Quantile algorithm, Gene Spring Software 11.0 (Agilent technologies, Santa Clara, CA, US). The ratio of transcript level between wildtype and mutant can been achieved using the formula: 2^(value of wildtype)/2^(value of ccpA mutant).
Project description:Clostridium acetobutylicum is a Gram-positive, endospore-forming bacterium that is considered as a strict anaerobe. It ferments sugars to the organic acids acetate and butyrate or shifts to formation of the solvents - ethanol, butanol and acetone. In most bacteria the major regulator of iron homeostasis is Fur (ferric uptake regulator). Analysis of the genome of Clostridium acetobutylicum has revealed three genes encoding Fur-like proteins. The amino acid sequece of one of them showed 70% similarity to the Fur protein of the closely related Bacillus subtilis.<br>Thus, to gain insight into the role of Fur and the mechanisms for maintenance of iron homeostasis in this strict anaerobic organism, we determined its transcriptional profile in response to iron limitation and inactivation of fur.
Project description:Little is known regarding the entry into and the regulation of genes during the sporulation process of clostridia. Using C. acetobutylicum as a model organism we designed an antisense RNA construct targeting the CAC0654 gene to investigate the role of this gene during sporulation and solvent formation. Samples were taken throughout the growth phase and compared to a plasmid control strain to elucidate the transcriptional changes induced by the downregulation of the two-component system CAC0653 and CAC0654
