Project description:Previously, we performed DNA array-based transcriptomic analysis of Clostridium acetobutylicum biofilm adsorbed onto fibrous matrix in batch fermentation. Here, to further shed light on the transcriptomic modulation of maturing Clostridium acetobutylicum biofilm, we performed the DNA array-based transcriptomic analysis in repeated-batch fermentation. Significant time course changes in expression levels were observed for the genes involved in amino acid metabolism, oligopeptide ABC transporter, nitrogen fixation, and various other processes.
Project description:Immobilization of Clostridium acetobutylicum B3 onto fibrous matrix by surface-adsorption was developed and applied to biobutanol production. The immobilized C. acetobutylicum B3 cells formed biofilm and showed dramatically improved butanol tolerance and production rate. DNA array-based transcriptional analysis of C.acetobutylicum B3 biofilm cells was conducted to elucidate the gene expression profile of the biofilm cells. Results showed that about 16% of the whole genome was differentially expressed. The most apparently differentially expressed genes were involved in amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, and coenzyme transport and metabolism.
Project description:Immobilization of Clostridium acetobutylicum B3 onto fibrous matrix by surface-adsorption was developed and applied to biobutanol production. The immobilized C. acetobutylicum B3 cells formed biofilm and showed dramatically improved butanol tolerance and production rate. DNA array-based transcriptional analysis of C.acetobutylicum B3 biofilm cells was conducted to elucidate the gene expression profile of the biofilm cells. Results showed that about 16% of the whole genome was differentially expressed. The most apparently differentially expressed genes were involved in amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, and coenzyme transport and metabolism.
Project description:Immobilization of Clostridium acetobutylicum B3 onto fibrous matrix by surface-adsorption was developed and applied to biobutanol production. The immobilized C. acetobutylicum B3 cells formed biofilm and showed dramatically improved butanol tolerance and production rate. DNA array-based transcriptional analysis of C.acetobutylicum B3 biofilm cells was conducted to elucidate the gene expression profile of the biofilm cells. Results showed that about 16% of the whole genome was differentially expressed. The most apparently differentially expressed genes were involved in amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, and coenzyme transport and metabolism. Samples for biofilm cells and planktonic cells were withdrawn at four diffierent fermentation phases. The gene expression pattern of biofilm cells were investigated relative to that of planktonic cells from the same phase. The experiment was carried out twice independently. Cotton fibrous matrix (60 g/L) was used as biofilm carrier.
Project description:Immobilization of Clostridium acetobutylicum B3 onto fibrous matrix by surface-adsorption was developed and applied to biobutanol production. The immobilized C. acetobutylicum B3 cells formed biofilm and showed dramatically improved butanol tolerance and production rate. DNA array-based transcriptional analysis of C.acetobutylicum B3 biofilm cells was conducted to elucidate the gene expression profile of the biofilm cells. Results showed that about 16% of the whole genome was differentially expressed. The most apparently differentially expressed genes were involved in amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, and coenzyme transport and metabolism. Samples for biofilm cells and planktonic cells were withdrawn at four diffierent fermentation phases. The gene expression pattern of biofilm cells were investigated relative to that of planktonic cells from the same phase. The experiment was carried out twice independently. Cotton fibrous matrix (60 g/L) was used as biofilm carrier.
Project description:Previously, we performed DNA array-based transcriptomic analysis of Clostridium acetobutylicum biofilm adsorbed onto fibrous matrix in batch fermentation. Here, to further shed light on the transcriptomic modulation of maturing Clostridium acetobutylicum biofilm, we performed the DNA array-based transcriptomic analysis in repeated-batch fermentation. Significant time course changes in expression levels were observed for the genes involved in amino acid metabolism, oligopeptide ABC transporter, nitrogen fixation, and various other processes. Repeated-batch fermentation was carried out in 2-L stainless steel columns packed with 40 g of cotton towel ?cut into pieces?approximately 3 cm × 5 cm) containing 1.5 L of P2 medium. Medium circulation rate was maintained at 35 mL/min via a peristaltic pump and the temperature was controlled at 37°C. Fermentation broth was replaced with fresh P2 medium every 12 h. Samples were withdrawn at 6 h after the medium replacement at predetermined interval, except for the last 3 samples. The last 3 samples were withdrawn at 12 h, 15 h, and 17 h after the medium replacement, respectively, to study the transcriptomic response to the adverse condition at the end of fermentation. A total of 8 samples were withdrawn over a period of 7 days, and time course gene expression profiles were studied.
Project description:Clostridium acetobutylicum has been extensively exploited to produce biofuels and solvents and its biofilm could dramatically improve its productivities. However, genetic control of C. acetobutylicum biofilm has not been dissected so far. Here, a total of 24 disruptants were finally obtained over several years of attempts. Biofilm formation and physiological phenotypes were characterized for these disruptants and most of them showed robust biofilm formation still, or showed both impaired biofilm formation and cell growth. Only a mutant with a disputed histidine kinase gene (CA_C2730, designated bfcK in this study) abolished biofilm formation without impaired cell growth or solvent production. Phosphoproteomic analysis revealed that bfcK could control C. acetobutylicum flagellar motility at both translational and post-translational (protein phosphorylation) levels. The bfcK also showed apparent regulation of a serine/threonine protein kinase (encoded by CA_C0404) which was involved in protein secretion. Based on these findings, possible bfcK-based mechanisms for biofilm formation in C. acetobutylicum were proposed.
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.