New and Improved yeast and bacterial starter cultures-novel attributes, process efficiency and wine distinctiveness
Summary
Objective
The core objective of this project is to improve the wine microbial toolkit available for fermentation and provide a robust and tailored suite of yeast and bacteria specifically targeted to address wine sector requirements. Efforts will be directed at current challenges and the winemaker’s needs for distinct sensory or processing-related benefits of new strains.
Background
Once grapes have been harvested and crushed, Australian winemakers face many challenges to a successful fermentation. These include conditions such as those arising from dilution of high sugar juice, where new nutrient imbalances may complicate fermentation success and wine flavour profile. There is an opportunity to develop new microbial strains which move away from the generic optimisation of microbial process efficiency and towards today’s specific challenges.
Research approach
Directed evolution will be used in combination with other methodologies in small-scale ferments to generate improved yeast strains for starter cultures. Genome sequencing, RNA sequencing and/or QTL analysis will be used, as appropriate, to understand the underlying genetic basis for the successful fermentations.
In addition, opportunities for securing novel yeast attributes such as the ability to enhance wine flavour, colour, mouthfeel and freshness, and innovative ways to use microbes to reduce additives/downstream processing (e.g. protein stability, SO2 additions, etc), will be investigated.
The processes above will also be applied to generation or isolation of improved lactic acid bacteria, and data collected on the presence of novel inhibitors or bacteriophages in wineries with failed malolactic fermentation.
Yeast and/or lactic acid bacterial strains with enhanced or distinct properties will be offered to starter culture companies for evaluation for commercialisation.
Sector benefits
New and improved yeast and bacterial cultures will be available to the wine sector to improve winemaking process efficiency and sensory outcomes. In addition, understanding of the genetic basis of improvements in wine microbes will enable further ‘mining’ for genetic modification or selection for desirable fermentation traits.