Project description:Transcriptomic analyses of fermenting yeast are increasingly being carried out under small scale simulated winemaking conditions. It is not known to what degree data generated from such experiments are a reflection of transcriptional processes in large-scale commercial fermentation tanks. In this experiment we set out to determine the effect of scale, or fermentation volume, on the transcriptional respone of wine yeast strains. Parallel fermentations were carried out in laboratory fermentation vials and commercial fermentation tanks using the same wine media and inoculated yeast strain. Comparative transcriptomic analyses were carried out at three time points during alcoholic fermentation.
Project description:Transcriptomic analyses of fermenting yeast are increasingly being carried out under small scale simulated winemaking conditions. It is not known to what degree data generated from such experiments are a reflection of transcriptional processes in large-scale commercial fermentation tanks. In this experiment we set out to determine the effect of scale, or fermentation volume, on the transcriptional respone of wine yeast strains. Parallel fermentations were carried out in laboratory fermentation vials and commercial fermentation tanks using the same wine media and inoculated yeast strain. Comparative transcriptomic analyses were carried out at three time points during alcoholic fermentation. Fermentations were carried out in Chardonnay wine must in triplicate for both the lab-scale (80ml) and commercial scale (300L) fermentations. Sampling of yeast for RNA extractions were performed at day 2 of fermentation (during the exponential growth phase of the yeast cells), and again at day 5 (early stationary growth phase) and day 10 (late stationary growth phase) of fermentation.
Project description:In wine fermentation, the blending of non-Saccharomyces yeast with Saccharomyces cerevisiae to improve the complexity of wine has become common practice, but data regarding the impact on yeast physiology and on genetic and metabolic regulation remain limited. Here we describe a transcriptomic analysis of single species and mixed species fermentations.
Project description:Comparative genome-wide gene expression analysis between a wine yeast strain belonging to the species S. cerevisiae and the type strain from S. kudriavzevii IFO1802, a cryotolerant yeast, in natural must fermentations.
Project description:In order to asses yeast EC1118® strain expression changes during wine alcoholic fermentation triggered by various nutrient starvations, this experiment describes the gene expression under micronutrient starvations that lead to yeast cell death (oleic acid starvation, ergosterol starvation, pantothenic acid starvation and nicotinic starvation) or allow the maintenance of yeast viability (nitrogen starvation).
Project description:Natural grape-juice fermentations involve the sequential development of different yeast species which strongly influence the chemical and sensorial traits of the final product. In the present study,we aimed to examine the transcriptomic response of Saccharomyces cerevisiae to the presence of Hanseniaspora guilliermondii wine fermentation. Paralell fermentations were carried out in natural grape-juice using S. cerevisiae for both single and mixed culture with a H. guilliermondii strain. For RNA extraction, cells were collected at 24h, 48h and 96 h from both fermentations
Project description:Yeast cells can be affected during their growth to several stress conditions. One of the most known and characterised is the osmotic stress and most of the studies about osmotic sterss response in yeast have been focused on salt or sorbitol stress. However, during yeast growth in industrially relevant processes (for instance throughout alcoholic fermentation on the must to produce alcoholic beverages) the osmotic stress is mainly due to the high sugar(in particular glucose) concentration (200-250 g/L).
Project description:In this study we investigate the molecular physiology of the main S. cerevisiae commercial strain (PE-2) used on Brazilian bioethanol process under two distinct conditions: typical (TF) and flocculated (co-aggregated - FL) fermentation. Transcriptional machinery of PE-2 was assessed by high throughput sequencing-based methods (RNA-seq) during industrial fed-batch fermentations. Data from comparative analysis revealed distinct transcriptional profiles among conditions, characterized mainly by a deep gene repression on FL process.
Project description:Natural grape-juice fermentations involve the sequential development of different yeast species which strongly influence the chemical and sensorial traits of the final product. In the present study,we aimed to examine the transcriptomic response of Saccharomyces cerevisiae to the presence of Hanseniaspora guilliermondii wine fermentation.
