Grant: Collaborative Research and Development Grants

Saccharomyces cerevisiae responds transcriptionally to stress by general and/or stimuli-specific response mechanisms. We identified 62 non-annotated genes exhibiting sustained and dramatic induction (4 to 80-fold) during wine fermentation and named these genes the Fermentation Stress Response (FSR) genes. Over the past three years we have studied the biological functions of these 62 non-annotated S. cerevisiae FSR genes. We used a systems biology approach and have now successfully elucidated the functions of thee non-annotated FSR genes, which will lead to a patent. In this grant proposal we will use the same approach, transcriptomics, proteomics and metabolomics, to study the functions of an additional 150 non-annotated genes in the M2 industrial wine yeast strain during Chardonnay fermentations; these genes are constitutively expressed and thus play an important role during wine fermentations. Our objective is to determine the functions of as many as possible of the 150 non-annotated genes, and to establish how metabolic and regulatory networks where these genes are involved, function and interact to allow S. cerevisiae to adapt to the extreme conditions experienced during wine making. The identification and characterization of regulatory circuits that regulate metabolism during wine fermentations will provide an insight into the remarkable ability of S. cerevisiae to flourish and ferment grape must and then survive the hostile environment of wine for months. We will also investigate whether S. cerevisiae contains a signal transduction pathway enabling yeast cells to adapt and tolerate higher concentrations of ethanol, the primary product of the alcoholic fermentation process. If such a pathway exists, modification of this signal transduction pathway can lead to yeasts that might tolerate higher concentrations of ethanol, which will be useful for the commercial production of ethanol.