Project description:Saccharomyces pastorianus is the yeast used to make lager beer; it is known to be an interspecific hybrid formed by the fusion between S. cerevisiae and S. bayanus genomes. This data set queries 17 S. pastorianus strains, collected at various times over the last 125 years from various breweries located in different geographical locations, which were obtained from CBS and DBVPG culture collections. The data in this set represent array-CGH experiments performed with these strains, using "2-species" custom Agilent arrays (the "2-species" arrays contain probes spaced every ~2 kb across the whole genomes of both S. cerevisiae and S. bayanus; the probes are unique and specific for each genome). The data set also contains 3 self-self hybridizations (S. cerevisiae + S. bayanus DNA mixed together in equimolar amounts, then labeled green or red in separate reactions, then hybridized to the "2-species" arrays) used for normalization in CGH-Miner analysis. A strain or line experiment design type assays differences between multiple strains, cultivars, serovars, isolates, lines from organisms of a single species.
Project description:We report the gene expression profile of two polypolid Saccharomyces pastorianus, lager yeast strains, the Group I strain CBS1538 and the Group II strain W34/70. Saccharomyces pastorianus is a hybrid of Saccharomuyces cerevisiaie and Saccharomyces eubayanus. We report that the gene expression patterns are correlated with the gene copy number of S. cerevisiae and S. eubayanus alleles.
Project description:Saccharomyces pastorianus is the yeast used to make lager beer; it is known to be an interspecific hybrid formed by the fusion between S. cerevisiae and S. bayanus genomes. This data set queries 17 S. pastorianus strains, collected at various times over the last 125 years from various breweries located in different geographical locations, which were obtained from CBS and DBVPG culture collections. The data in this set represent array-CGH experiments performed with these strains, using "2-species" custom Agilent arrays (the "2-species" arrays contain probes spaced every ~2 kb across the whole genomes of both S. cerevisiae and S. bayanus; the probes are unique and specific for each genome). The data set also contains 3 self-self hybridizations (S. cerevisiae + S. bayanus DNA mixed together in equimolar amounts, then labeled green or red in separate reactions, then hybridized to the "2-species" arrays) used for normalization in CGH-Miner analysis. A strain or line experiment design type assays differences between multiple strains, cultivars, serovars, isolates, lines from organisms of a single species. Keywords: strain_or_line_design
Project description:S. pastorianus strains are hybrids of S. cerevisiae and S. eubayanus that have been domesticated for several centuries in lager-beer brewing environments. As sequences and structures of S. pastorianus genomes are being resolved, molecular mechanisms and evolutionary origin of several industrially relevant phenotypes remain unknown. This study investigates how maltotriose metabolism, a key feature in brewing, may have arisen in early S. eubayanus x S. cerevisiae hybrids. To address this question, we generated a near-complete genome assembly of Himalayan S. eubayanus strains of the Holarctic subclade. This group of strains have been proposed to be the origin of the S. eubayanus subgenome of current S. pastorianus strains. The Himalayan S. eubayanus genomes harbored several copies of an SeAGT1 -oligoglucoside transporter gene with high sequence identity to genes encountered in S. pastorianus. Although Himalayan S. eubayanus strains are unable to grown on maltose and maltotriose, their maltose-hydrolase and SeMALT1 and SeAGT1 maltose-transporter genes complemented the corresponding null mutants of S. cerevisiae. Expression, in a Himalayan S. eubayanus strain, of a functional S. cerevisiae maltose-metabolism regulator gene (MALx3) enabled growth on oligoglucosides. The hypothesis that the maltotriose-positive phenotype in S. pastorianus is a result of heterosis was experimentally tested by constructing a S. cerevisiae x S. eubayanus laboratory hybrid with a complement of maltose-metabolism genes that resembles that of current S. pastorianus strains. The ability of this hybrid to consume maltotriose in brewer's wort demonstrated regulatory cross talk between sub-genomes and thereby validated this hypothesis. These results provide experimental evidence of the evolutionary origin of an essential phenotype of lager-brewing strains and valuable knowledge for industrial exploitation of laboratory-made S. pastorianus-like hybrids.
Project description:Chromosomal copy number variation in Saccharomyces pastorianus: evidence for extensive genome dynamics in industrial lager brewing strains.
Project description:A transcriptome analysis of the bottom-fermenting yeast S. pastorianus KBY011 during a time course of lager beer fermentation in the wort was carried out (0, 2, 6, 8, 10, 14, 24, 34, 40, 52, 64, 120, and 156h). RNA preparation followed by DNA microarray analysis was performed for the yeast harvested from the yeast storage tank either just prior to, or just after the actual fermentation, as well as from 12 different time points during fermentation.
Project description:Four hybrid yeast strains isolated from a variety of industrial substrates were hybridized to an array-CGH platform containing probes to query the whole genomes of seven different Saccharomyces species. For most of the strains we found evidence of multiple interspecific hybridization events and multiple introgressed regions. The strains queried were GSY205 (isolated from a cider fermentation), GSY505 (a contaminant from a lager beer fermentation), GSY2232 (a commercial wine yeast strain), and GSY312 (a commercial lager beer strain). Additionally, 3 different rare viable spores derived from laboratory-created interspecific S. cerevisiae-S. bayanus (aka S. uvarum) hybrids were queried, before and after evolution in chemostats, via S. cerevisiae-S. bayanus microarrays.