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:Four C. thermocellum DSM-1313 derived strains were assessed using metabolite and DNA microarray tools in order to better understand carbon and electron flow within this organism. C. thermocellum is able to ferment cellulose into its fermentation end products L-lactate, acetate, formate, hydrogen gas, and ethanol, with the latter being the desired end product to be used as biorenewable fuel. In addition to the parent strain (genotype: hpt spo0A), strains with either or both of the genes encoding lactate dehydrogenase (ldh) and phosphate acetyltransferase (pta) deleted were studied. The strains used are a parent strain (M1726: genotype: hpt spo0A), and strains with either the gene encoding lactate dehydrogenase (M1629: hpt spo0A ldh) or phosphate acetyltransferase (M1630: hpt spo0A pta) deleted, or with both genes deleted (M1725: hpt spo0A ldh pta). Controlled batch fermentations using cellobiose as sole carbon source were grown for each strain, and samples in mid-exponential phase and at the time of carbon depletion were examined by DNA microarray. Four strains were grown each as three independent biological replicates (fresh batch of media was made before each run). Per fermentation, two samples were taken for DNA microarray analysis as was determined by the optical density: mid-exponential was defined as O.D. 0.4 (measured by Dasgip probe); point of carbon depletion was defined by both the maximum O.D. reached and observation that no base was added to the fermentation to control pH. In total, 4 strains x 3 fermentation x 2 time points per fermentor = 24 arrays. Parent strain was used as reference strain.
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:Four C. thermocellum DSM-1313 derived strains were assessed using metabolite and DNA microarray tools in order to better understand carbon and electron flow within this organism. C. thermocellum is able to ferment cellulose into its fermentation end products L-lactate, acetate, formate, hydrogen gas, and ethanol, with the latter being the desired end product to be used as biorenewable fuel. In addition to the parent strain (genotype: hpt spo0A), strains with either or both of the genes encoding lactate dehydrogenase (ldh) and phosphate acetyltransferase (pta) deleted were studied. The strains used are a parent strain (M1726: genotype: hpt spo0A), and strains with either the gene encoding lactate dehydrogenase (M1629: hpt spo0A ldh) or phosphate acetyltransferase (M1630: hpt spo0A pta) deleted, or with both genes deleted (M1725: hpt spo0A ldh pta). Controlled batch fermentations using cellobiose as sole carbon source were grown for each strain, and samples in mid-exponential phase and at the time of carbon depletion were examined by DNA microarray.
Project description:The goal of this experiment is compare gene expression profiles between C. acetobutylicum wild-type and pks mutant strains to determine which genes might be under the control of self-produced polyketides. Samples for RNA-seq comparison were taken from batch fermentation cultures 26 hours post-inoculation.
Project description:A longitudinal multi-omics analysis was carried out over a 26-hour small-scale fermentation of B. pertussis. Fermentations were performed in batch mode and under culture conditions intended to mimic industrial processes.