A Novel Approach to Isolating Improved Industrial Interspecific Wine Yeasts Using Chromosomal Mutations as Potential Markers for Increased Fitness.

Jennifer R Bellon,Anthony R Borneman,Christopher M Ford,Paul J Chambers

doi:10.3389/fmicb.2018.01442

Jennifer R Bellon, Anthony R Borneman + Show 2 more

Open Access

https://doi.org/10.3389/fmicb.2018.01442

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Abstract

Wine yeast breeding programs utilizing interspecific hybridization deliver cost-effective tools to winemakers looking to differentiate their wines through the development of new wine styles. The addition of a non-Saccharomyces cerevisiae genome to a commercial wine yeast can generate novel phenotypes ranging from wine flavor and aroma diversity to improvements in targeted fermentation traits. In the current study we utilized a novel approach to screen isolates from an evolving population for increased fitness in a S. cerevisiae × S. uvarum interspecific hybrid previously generated to incorporate the targeted phenotype of lower volatile acidity production. Sequential grape-juice fermentations provided a selective environment from which to screen isolates. Chromosomal markers were used in a novel approach to identify isolates with potential increased fitness. A strain with increased fitness relative to its parents was isolated from an early timepoint in the evolving population, thereby minimizing the risk of introducing collateral mutations and potentially undesirable phenotypes. The evolved strain retained the desirable fermentation trait of reduced volatile acidity production, along with other winemaking traits of importance while exhibiting improved fermentation kinetics.

Highlights

An increasingly competitive global market requires winemakers to minimize production costs and target market niches by differentiating their wines through, for example, development of novel wine styles
One way of achieving these ends is to generate new yeast strains with improved fermentation traits and/or novel phenotypes that shape wine flavor and aroma
Saccharomyces spp. interspecific hybrid strain AWRI 1572, generated using rare-mating hybridization between S. cerevisiae diploid strain (AWRI 838) and spores from Saccharomyces uvarum strain AWRI 1176 as described in Bellon et al (2015); hybrid strain AWRI 2530 and control yeast strains for haploid, diploid and tetraploid DNA intensity determinations BY4741 MATa, BY4743 (Euroscarf R, Frankfurt, Germany) and 53-7 (Salmon, 1997) respectively

Summary

Introduction

An increasingly competitive global market requires winemakers to minimize production costs and target market niches by differentiating their wines through, for example, development of novel wine styles. One way of achieving these ends is to generate new yeast strains with improved fermentation traits and/or novel phenotypes that shape wine flavor and aroma. Such yeasts provide winemakers with tools that are readily and introduced into the winery without incurring additional costs or requiring processing interventions. There are various ways to generate new yeast strains, including breeding programs. This would involve mating strains of the same species, which, in the context of wine yeast, is Saccharomyces cerevisiae.

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