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:Metabolite accumulation has pleiotropic, including toxic, effects on cellular physiology, but such effects are not well understood at the genomic level. Using DNA microarrays, the Clostridium acetobutylicum transcriptional stress response to acetate was analyzed. Keywords: stress response
Project description:Metabolite accumulation has pleiotropic, including toxic, effects on cellular physiology, but such effects are not well understood at the genomic level. Using DNA microarrays, the Clostridium acetobutylicum transcriptional stress response to butanol was analyzed. Keywords: stress response
Project description:Metabolite accumulation has pleiotropic, including toxic, effects on cellular physiology, but such effects are not well understood at the genomic level. Using DNA microarrays, the Clostridium acetobutylicum transcriptional stress response to butyrate was analyzed. Keywords: stress response
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 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.
