Grant: Discovery Grants Program - Individual

The long term objective of my research program is to understand which stress related pathways are required for yeast survival during industrial wine fermentations.  The yeast Saccharomyces cerevisiae (S. cerevisiae) has served as a model organism to study fundamental aspects of biology in eukaryotes.  Significant research advances have been achieved with laboratory strains of S. cerevisiae including the sequencing of its genome, systematic deletion of every gene and genome-wide expression analysis.  Despite the major advances in characterizing S. cerevisiae in the laboratory, we have a very limited understanding of gene function in yeast during fermentations.  Only 20% of genes in the S. cerevisiae genome were found to be essential for growth in standard laboratory glucose media, which contains 2% glucose.  However in the vineyard and in the winery, yeast are exposed to much higher sugar concentrations (~20% sugar) from grapes.  It is likely that many of the genes presently considered nonessential for growth and genes of unknown function will have a role during growth in high sugar stress conditions.  My proposal aims to use the genomic resources available in lab yeast to identify genes that are required for tolerance to fermentation related stress conditions such as high sugar concentration.  Each yeast gene has been systematically deleted from the genome and unique sequence tags (molecular bar codes) placed in each gene deletion to allow the strains to be analyzed in parallel.  My lab will use the bar code technology to identify genes important for stress response during yeast fermentation.  Approximately 1,000 out of 6,000 S. cerevisiae yeast genes have no known function.  By studying S. cerevisiae gene function under the natural and industrial environment that yeast has been exposed, to we aim to attribute functions for uncharacterized yeast genes that could not otherwise be characterized using conventional laboratory conditions.  The ultimate goal is that my research will have practical implications for the growing wine industry in Canada by predicting and improving stress response in wine yeast.