Project description:A time-course transcriptomic experiment was performed in three geographically different wine yeast strains in order to test differences in gene expression as response to different nitrogen availability
Project description:Comparison of 3 yeast strains grown under nitrogen starvation, nitrogen rich conditions, with and without quorum sensing molecule 2-phenylethanol
Project description:A time-course transcriptomic experiment was performed in three geographically different wine yeast strains in order to test differences in gene expression as response to different nitrogen availability mRNA amounts for different wine yeast strains at different nitrogen availability was determined along the fermentation of a syntethic must. mRNA determinations were made at different fermentation stages (12, 24, 36 and 96 h after innoculation) Please note that there are two replicates per each stage (i.e. two raw data files per each sample; R1.txt and R2.txt) and the data were combined to generate the normalized data for each stage (i.e. sample).
Project description:To characterize the ecological interactions among S. cerevisiae strains coming from the same geographical area, we examined the fitness of two natural isolates from San Giovese grapes, alone or in competition, in synthetic wine must (SWM). We performed genome-wide analyses in order to identify the genes involved in yeast competition and cooperation.
Project description:To characterize the ecological interactions among S. cerevisiae strains coming from the same geographical area, we examined the fitness of two natural isolates from San Giovese grapes, alone or in competition, in synthetic wine must (SWM). We performed genome-wide analyses in order to identify the genes involved in yeast competition and cooperation.
Project description:Laboratory strains of Saccharmoyces cerevisiae have been widely used as a model for studying eukaryotic cells and mapping the molecular mechanisms of many different human diseases. Industrial wine yeasts, on the other hand, have been selected over hundreds of years on the basis of their adaptation to stringent environmental conditions and the organoleptic properties they confer to wine. Here, we applied a two-factor design to study the response of a standard laboratory strain, CEN.PK.113-7D, and an industrial wine yeast-strain, EC1118, to growth temperature at 15°C and 30°C under 12 nitrogen-limited, anaerobic steady-state chemostat cultures. Physiological characterization revealed that growth temperature strongly impacted biomass yields in both strains. Moreover, we observed that the wine yeast is better adapted to mobilizing resources for biomass and that the laboratory yeast exhibited higher fermentation rates. To elucidate mechanistic differences controlling the growth temperature response and underlying adaptive mechanisms between strains, DNA microarrays and targeted metabolome analysis were used. We identified 1007 temperature dependent genes and 473 strain dependent genes. The transcriptional response was used to identify highly correlated subnetworks of significantly changing genes in metabolism. We show that temperature differences most strongly affect nitrogen metabolism and the heat shock response. Lack of STRE mediated gene induction, coupled with reduced trehalose levels, indicates a decreased general stress response at 15°C relative to 30°C. Between strains, differential responses are centred around sugar uptake, nitrogen metabolism and expression of genes related to organoleptic properties. Our study provides global insight into how growth temperature exerts a differential physiological and transcriptional response in laboratory and wine strains of S. cerevisiae.
Project description:Oxygen additions play a critical role in winemaking. However, few studies have focused on how this oxygen affects yeast metabolism and physiology in wine making conditions. We performed microarrays to unveil the oxygen response in wine making conditions. We extracted RNA from nitrogen-limited chemostats, simulating wine making conditions, sparged with nitrogen and 1%, 5% and 20% oxygen-nitrogen mixtures to achieve different dissolved oxygen levels representative of those found during wine making. These correspond to 0, 0.8, 4 and 11 micromolar dissolved oxygen
