Project description:Bordetella pertussis is the bacterial causative agent of whooping cough, a serious respiratory illness. An extensive knowledge on its virulence regulation and metabolism is a key factor to ensure pertussis vaccine manufacturing process robustness. The aim of this study was to refine our comprehension of B. pertussis physiology along the fermentation process. 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 intending to mimic industrial processes. Putative cysteine and proline starvations were respectively observed at the beginning of the exponential phase (from 4h to 8h) and during the exponential phase (18h45). As revealed by multi-omics analyses, the proline starvation induced major molecular changes, including a transient metabolism with internal stock consumption. In the meantime, growth and specific total PT, PRN and Fim2 antigen productions were negatively affected. Interestingly, the master virulence-regulating two-component system of B. pertussis (BvgASR) was not evidenced as the sole virulence regulator in this in vitro growth condition. Indeed, novel intermediate regulators were identified as putatively involved in the expression of some virulence-activated genes (vags). Such longitudinal multi-omics analysis applied to B. pertussis fermentation process emerges as a powerful tool for characterization and incremental optimization of vaccine antigen production.
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:The fermentable carbohydrate composition of wort and the manner in which it is utilised by yeast during brewery fermentation has a direct influence on fermentation efficiency and quality of the finished product. In this study the response of a brewing yeast strain to changes in wort fermentable carbohydrate concentration and composition during full-scale (3275 hL) brewery fermentation was investigated by measuring transcriptome changes with the aid of oligonucleotide based DNA arrays. Up to 90% of the detectable genes showed a significant (P ≤ 0.05) differential expression pattern during fermentation and the majority of these genes showed either transient or prolonged peaks in expression following the exhaustion of the monosaccharides glucose and fructose from the wort. Those which did not display this apparent carbon catabolite derepression response were mainly those genes involved in cytokinesis and cell budding, which had higher expression values during active growth of cells. Transcriptional activity of many genes was consistent with their known responses to glucose de/repression under laboratory conditions, despite the presence of di- and trisaccharide sugars in the wort. Experimenter name: Katherine Smart Experimenter phone: 0044-1159516214 Experimenter address: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire Experimenter zip/postal_code: LE12 5RD Experimenter country: England Keywords: time series design
Project description:The first aim was to investigate the suitability of FSCF to analyze yeast physiology during the stationary phase of wine making. In this way, a comparative transcriptomic analysis was performed on mRNA samples collected from the third stage of FSCF and from batch culture, at the same fermentation progress (164 g/L residual glucose). In a second part, FSCF device was used to study the impact at the transcriptomic level of nitrogen addition performed at the beginning of the stationary phase. Gene expression profiles were compared at steady state between cells from the third stage of FSCF operating in presence or absence of continuous valine or ammonium perfusion.
Project description:To select candidate promoters that function in the presence of xylose, we performed comprehensive gene expression analyses using xylose-utilizing yeast strains both during xylose and glucose fermentation.
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.
