Project description:Wine biological aging is a wine making process used to produce specific beverages in several countries in Europe, including Spain, Italy, France, and Hungary. This process involves the formation of a velum at the surface of the wine. Here, we present the first large scale comparison of all European flor strains involved in this process. We inferred the population structure of these European flor strains from their microsatellite genotype diversity and analyzed their ploidy. We show that almost all of these flor strains belong to the same cluster and are diploid, except for a few Spanish strains. Comparison of the array hybridization profile of six flor strains originating from these four countries, with that of three wine strains did not reveal any large segmental amplification. Nonetheless, some genes, including YKL221W/MCH2 and YKL222C, were amplified in the genome of four out of six flor strains. Finally, we correlated ICR1 ncRNA and FLO11 polymorphisms with flor yeast population structure, and associate the presence of wild type ICR1 and a long Flo11p with thin velum formation in a cluster of Jura strains. These results provide new insight into the diversity of flor yeast and show that combinations of different adaptive changes can lead to an increase of hydrophobicity and affect velum formation.
Project description:The yeast Saccharomyces cerevisiae is a model for biology and is also one of the most important microorganisms for food and drink production. Surprisingly, only a few genes involved in the adaptation to anthropic niches have been described until now. Wine fermentation and flor aging, which are performed by strains from two closely related groups of yeast, are two technologies that have opposite approaches toward oxygen, which results in contrasting lifestyles for yeast: fermentation growth on grape for wine yeast, and biofilm aerobic growth on ethanol and glycerol contained in wine for flor strains. This pair of environments and the associated yeast populations can be a model for studying adaptation to anthropic environments. In this project, we have obtained high-quality genome sequences of 20 yeast strains from 9 flor yeast, 9 wine yeast as well as EC1118 and haploid derivative 59A. Phylogeny and population structure analysis, based on GATK genotyping, enable us to characterize a group of flor yeast that is clearly different from wine yeast. A comparison of the genomes of wine and flor yeasts using various methods (PCA, nucleotidic diversity, McDonald Kreitman test, potentially impacted genes according to SIFT) enabled us to note divergent regions, or genes, with potential non-neutral evolution, and highly variant genes. The results of these genomic comparisons are echoed by the comparison of a wine and a flor yeast transcriptome. These methods, as expected, highlight key genes that are involved in FLO11 regulation as well as in biofilm growth, but they also revealed the presence of many allelic variations in genes that are involved in the sensing and regulation of osmotic pressure (such as SLN1, HKR1, SSK22, AQY2) and specific metabolic traits, such as the fructophily of flor yeast, which carry a fructophile allele of HXT3. More remarkable is the accumulation of mutations in multiple genes, which creates a pattern of convergent mutations in regulatory networks, as seen in FLO11 regulation or the HOG MAP kinase pathway. The rewiring of these regulatory networks is clearly one of the hallmarks of domestication for the flor yeast genome. Data presented here correspond to the comparison of Flor yeast P3-D5 and wine yeast K1-280-2B transcriptomes under conditions potentially enabling the production of a biofilm.
Project description:Wine biological ageing is led in different countries in Europe: Spain, Italy, France, and Hungary, but until now no comparison of all these flor strains has been led. In this manuscript we investigated the population structure of these European flor strains from their microsatellite genotypes and analysed as well as their ploidy. We showed that almost all of these strains belong to the same cluster, and are mainly diploids. In order to detect a shared amplification pattern, we compared the hybridization profile on array of 6 flor strains from these four countries, and found only 2 genes amplified in the genome of 4 strains. Finally FLO11 polymorphism analysis revealed that most strains carry a 111 deletion in ICR1 non coding RNA, except a group of Jura Flor strains, which in contrast presented longer central core of the protein Flo11p. These results show that amplification is very likely not the main mechanism leading to the adaptation of flor yeast, and suggest that different adaptive itineraries can leading to an increase of hydrophobicity and velum formation. Wine and flor strains hybridization on affymetrix yeast2 arrays are compared to S288C Each strain is compared to S288C and is hybridized in duplicate or triplicate
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: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:By an evolutionary approach based on long-term culture on gluconate as the sole carbon source, a Saccharomyces cerevisiae wine strains with enhanced flux through the pentose phosphate (PP) pathway were obtained. One of these evolved strains, ECA5, exhibited several novel properties with great potential for wine making, including a higher than wild-type fermentation rate and altered production of acetate and aroma compounds. To describe the mechanisms underlying this complex phenotype, we performed a comparative analysis of transcriptomic profiles between ECA5 and its ancestral strain, EC1118, under low nitrogen, wine fermentation conditions.
Project description:Industrial wine yeast strains are geno- and phenotypically highly diversified, and have adapted to the ecological niches provided by industrial wine making environments. These strains have been selected for very specific and diverse purposes, and the adaptation of these strains to the oenological environment is a function of the specific expression profiles of their genomes. It has been proposed that some of the primary targets of yeast adaptation are functional binding sites of transcription factors (TF) and the transcription factors themselves. Sequence divergence or regulatory changes related to specific transcription factors would lead to far-reaching changes in overall gene expression patterns, which will in turn impact on specific phenotypic characteristics of different yeast species/ strains. Variations in transcriptional regulation between different wine yeast strains could thus be responsible for rapid adaptation to different fermentative requirements in the context of commercial wine-making. In this study, we compare the transcriptional profiles of five different wine yeast strains in simulated wine-making conditions: Comparative analyses of gene expression profiles in the context of TF regulatory networks provided new insights into the molecular basis for variations in gene expression in these industrial strains. We also show that the metabolic phenotype of one strain can indeed be shifted in the direction of another by modifying the expression of key transcription factors. SOK2 was one target transcription factor identified in this study. This expression factor was overexpressed in order to validate our hypotheses that altered expression levels of key transcription factors could shift metabolism in a directed, predicted manner.
Project description:We used RNA-seq to identify gene expression changes in C. elegans old-1(ok1273) and flor-1(icb93) mutants along with old-1 overexpression transgenic strains
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 ânoisyâ changes in gene expression in response to experimental factors such as fermentation stage and strain identity. Experiment Overall Design: Two industrial wine yeast strains (BM45 and VIN13) grown micro-aerobically in Colombar must. Microarray analysis was performed at three time points during fermentation (days 2, 5 and 14), representing the exponential, early and late stationary growth phases respectively.