CcpA, a Pleiotropic Key Regulator in Butanol-producing Clostridium acetobutylicum ATCC 824

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).