Transcriptomics of cryophilic Saccharomyces kudriavzevii reveals the key role of gene translation efficiency in cold stress adaptations
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ABSTRACT: 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. RNA samples taken from wine fermentations at 12M-BM-:C and 28M-BM-:C at the beginning of exponential phase. Three biological replicates.
Project description:Comparative genome-wide gene expression analysis between two industrial wine yeast hybrid strains belonging to the species S. cerevisiae x S. Kudriavzevii, in natural must 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:The aim of this project was to evaluate the ploidy of a S. cerevisiae *S. kudriavzevii hybrid in comparison to the lab strain S288C. Other wine yeast have been icluded in the project for the global analysis.
Project description:The aim of this project was to evaluate the ploidy of a S. cerevisiae *S. kudriavzevii hybrid in comparison to the lab strain S288C. Other wine yeast have been icluded in the project for the global analysis. Comparison of Eg8 (2 arays) , to S288C (3 arrays), other strains V5, U13, Eg25 (2 arrays) are used to enable signal normalization acccross arrays with RMA package.
Project description:Analysis of genomic variation in several Saccharomyces cerevisiae x S. kudriavzevii natural hybrids S. cerevisiae and S. kudriavzevii yeasts have been described among wine strains. These strains exhibit enological properties of interest for the wine industry. A preliminary characterization of these hybrids showed a trend to reduce the S. kudriavzevii fraction of the hybrid genome. As a first approach to understand the mechanisms involved in the genome changes occurred after hybridization that may account for differences in their enological properties, we characterized the genomic constitution of several wine S. cerevisiae x S. kudriavzevii strains by using a combined approach based on the RFLP analysis of gene regions, comparative genome hybridizations with S. cerevisiae DNA arrays, ploidy analysis and gene dose determination by quantitative real-time PCR. Genomic DNA hybridizations of w27, w46, SPG1691 and 441 hybrids were compared against the laboratory strain FY1679. Hybridizations were performed by triplicate in order to obtain the final CGH ratio.
Project description:Comparative gene expression analysis of two wine yeast strains at three time points (days 2, 5 and 14) during fermentation of colombar must. In our study we conducted parallel fermentations with the VIN13 and BM45 wine yeast strains in two different media, namely MS300 (syntheticmust) and Colombar must. The intersection of transcriptome datasets from both MS300 (simulated wine must;GSE11651) and Colombar fermentations should help to delineate relevant and ‘noisy’ changes in gene expression in response to experimental factors such as fermentation stage and strain identity.
Project description:The aim of this experiment is to characterize the genome composition of the two hybrids IF6 and MR25. IF6 and MR25 are hybrids among S.cerevisiae and S. kudriavzevii. The hybridization of the genome extraction with the microarray was at 65C, under this condition only S. cerevisiae genes can hybridize. In this case we are only studying the genome composition of S. cerevisiae parental in the hybrids. The study of S. kudriavzevii parental genome was done by other methods.
Project description:The yeast Dekkera bruxellensis is as ethanol tolerant as Saccharomyces cerevisiae and may be found in bottled wine. It causes the spoilage of wine, beer, cider and soft drinks. In wines, the metabolic products responsible for spoilage by Dekkera bruxellensis are mainly volatile phenols. These chemical compounds are responsible for the taints described as M-bM-^@M-^XM-bM-^@M-^XmedicinalM-bM-^@M-^YM-bM-^@M-^Y in white wines (due to vinyl phenols) and as M-bM-^@M-^XM-bM-^@M-^XleatherM-bM-^@M-^YM-bM-^@M-^Y, M-bM-^@M-^XM-bM-^@M-^Xhorse sweatM-bM-^@M-^YM-bM-^@M-^Y and M-bM-^@M-^XM-bM-^@M-^XstableM-bM-^@M-^YM-bM-^@M-^Y in red wines (due to ethyl phenols mainly 4-ethylphenol). Apart from the negative aroma nuances imparted by these yeasts, positive aromas such as M-bM-^@M-^XsmokyM-bM-^@M-^Y, M-bM-^@M-^XspicyM-bM-^@M-^Y and M-bM-^@M-^XtoffeeM-bM-^@M-^Y are also cited. Our goal was to identify the impact that the wine spoilage yeast Dekkera bruxellensis has on fermenting S. cerevisiae cells, especially on its gene expression level. To this end we co-inoculated both yeast species at the start of fermentation in a synthetic wine must, using S. cerevisiae-only fermentations without Dekkera bruxellensis as a control. All fermentations were employed in special membrane reactors (50 KDa pore size cut-off) physically separating Dekkera bruxellensis from wine yeast S. cerevisiae. Biomass separation with this membrane was done to abolish the possibility of hybridizing also D. bruxellensis probes on Agilent V2 (8x15K format) G4813 DNA microarrays designed just for S. cerevisiae ORF targets. The 50 KDa pore membrane separating both yeasts allowed the exchange of ethanol, metabolites and sugars during the fermentation. Fermentations were carried out in synthetic wine must in duplicate for both the control S. cerevisiae (strain Lalvin EC1118) and mixed fermentation. Sampling of yeast S. cerevisiae for RNA extractions were performed at 22 h of fermentation, during the exponential growth phase of S. cerevisiae, at 92 h and 144 h of fermentation, during its early and late stationary growth phase and at 187 h of fermentation, during its phase of growth decline.
Project description:Pichia kudriavzevii causes life-threatening infections in immune compromised hosts including hospitalized neonates. This pathogen is resistant to fluconazole while uncommon, strains resistant to multiple antifungal drugs voriconazole, amphotericin B and echinocandins have been reported in healthcare environments. Understanding how P. kudriavzevii spread, persist, and adapt to healthcare settings could help us develop better management strategies. In this study, whole genome sequencing identifies multiple outbreaks of bloodstream infections caused by P. kudriavzevii in a single neonatal intensive care unit (NICU) over five years. Interestingly, two genetically diverse clusters of P. kudriavzevii population showed frequent loss of heterozygosity (LOH) events between two temporal samples. The first outbreak cluster (during 2015-16) showed LOH at chromosomes 1, 4 and 5 and the other outbreak cluster (year 2020) exhibited marked LOH at chromosome 2. The circulation of two separate strain clusters of P. kudriavzevii suggests nosocomial transmission in the NICU in different time periods. Further, to evaluate the gene expression difference between isolates from two clusters, we compared the transcriptomic profiles of three isolates of cluster I and II and exhibiting distinct fluconazole MICs. While no difference was found at the azole target gene ERG11 or the ATP-binding cassette (ABC) transporter genes, differences in transcript abundance were found between the two isolates in genes coding for cell division and filamentation, repressor of ABC gene, FCR1 and ERG5 gene involved in ergosterol biosynthesis pathway. Our study indicates significant diversity, persistence, and rapid evolution of P. kudriavzevii within a single NICU.
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.