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SoCoBio (Universities of Southampton, Kent, Sussex, Portsmouth and NIAB EMR)

MAGIC Yeast: Quantitative genetic analysis of phenotypic variation within Saccharomyces cerevisiae from UK vineyards to identify and develop novel wine yeast strains

Primary Supervisor: Prof Richard Harrison (NIAB EMR)
Co-supervisor: Dr Jordan Price (NIB EMR)
Co-supervisor: Dr Julien Lecourt (NIB EMR)
Co-supervisor: Dr Tobias von der Haar (University of Kent)
Advisor: Prof Mick Tuite (University of Kent)

Project Summary

This project aims to explore natural variation in yeast in order to determine additional genetic components present in wild yeasts contributing to fermentation and flavour profiles.

The UK has one of the fastest growing wine sectors and with the East Malling Viticulture Research Consortium being established in 2016, we are strategically placed to develop oenological studies in order to help improve quality within the UK wine sector.

Spontaneous fermentation of wine lead to inconsistent results between batches, which is why the majority of commercial winemakers use defined starter cultures. However, artisanal and high value wines often use natural fermentations. The differences in fermentation performance and flavour profiles imparted by different wine yeast strains is genetically determined [1].

Of the 229 Saccharomyces cerevisiae wine strains sequenced, the majority originated from the major wine production locations; none were of UK origin [2]. To increase variation within wine yeast strains, we propose to isolate S. cerevisiae strains from UK vineyards and wineries, understand their genetic diversity and characterise their phenotypes in wine-relevant environments.

Winemaking traits, such as fermentation rate, desired fermentation by-products, and tolerance to stresses, are complex and quantitative, and these polygenic traits are difficult to transfer with traditional genetic engineering methods [3].

To identify the genetic loci responsible for these traits, we will apply a three step process for quantitative trait loci (QTL) mapping. Firstly, we will perform multi-parental crosses over multiple generations creating a large pool of recombinant individuals with varying levels of winemaking traits [4]. We will then grow this population in wine-relevant environments measuring key traits. Finally, population DNA sequencing will be performed to identify QTL at unrivalled precision [5].

These analyses will enable us to develop strategies for targeted selection and genomic prediction and for the creation of novel wine yeast strains that are optimised for fermentations with UK grown grape varieties.

[1] Chambers PJ, Pretorius IS. (2010) Fermenting knowledge: the history of winemaking, science and yeast research. EMBO Rep 11: 914-920

[2] Peter J, De Chiara M, Friedrich A, et al. (2018) Genome evolution across 1,011 Saccharomyces cerevisiae isolates. Nature 556: 339–344

[3] Hyma, KE, Saerens SM, Verstrepen KJ, Fay JC (2011) Divergence in wine characteristics produced by wild and domesticated strains of Saccharomyces cerevisiae. FEMS yeast research.

[4] Kover PX, Valdar W, Trakalo J, Scarcelli N, Ehrenreich IM, Purugganan MD, et al. (2009) A Multiparent Advanced Generation Inter-Cross to Fine-Map Quantitative Traits in Arabidopsis thaliana. PLoS Genet 5(7): e1000551

[5] Parts L, Cubillos FA, Warringer J, Jain K, Salinas F, et al. (2011) Revealing the genetic structure of a trait by sequencing a population under selection. Genome Res. 21(7): 1131-8