High-glutathione producing yeasts obtained by genetic improvement strategies: a focus on adaptive evolution approaches for novel wine strains

In yeasts, β-glucosidase activity has been extensively described, especially in non-Saccharomyces species, while there is only little evidence of this activity in strains belonging to the Saccharomyces species. In winemaking, β-glucosidase plays essential roles in the hydrolysis of glyco-conjugated precursors and the release of active aromatic compounds. This study provides new insights into the β-glucosidase activity in strains belonging to Saccharomyces cerevisiae and Saccharomyces uvarum species, which are the most important strains in wine industry. Our results point out a marked enzymatic activity for the tested S. uvarum strains. These strains could be exploited for their potential ability to enhance the aroma profiles of wine. In addition, they could be potential sources for the commercial production of enzymes to be applied in winemaking.

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“…; De Vero et al . , ). Although the mating frequency for crossings between S. cerevisiae and S. uvarum is low (Solieri et al .…”

Section: Resultsmentioning

confidence: 99%

Qualitative and quantitative screening of theβ-glucosidase activity inSaccharomyces cerevisiaeandSaccharomyces uvarumstrains isolated from refrigerated must

Bonciani

Vero

Giannuzzi

et al. 2018

Lett Appl Microbiol

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“…Random mutagenesis is based on the application of mutagens in order to improve the natural mutation rate of microorganisms. However, it has limited efficacy in wine yeasts, since they are usually diploid and homothallic ( De Vero et al, 2017 ), and phenotypic variants are produced at a slower rate. On the other hand, sexual hybridization strategies have been described as the most efficient way to generate artificial diversity in yeast.…”

Section: Introductionmentioning

confidence: 99%

Adaptive Laboratory Evolution of Native Torulaspora delbrueckii YCPUC10 With Enhanced Ethanol Resistance and Evaluation in Co-inoculated Fermentation

2020

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Torulaspora delbrueckii is a yeast species typically present in the early stages of the fermentation process. T. delbrueckii positively modifies the aromatic properties of wines. However, its contribution to the final quality of the wine is restricted by its low tolerance to ethanol. T. delbrueckii is capable of fermenting and tolerating an ethanol concentration ranging from 7.4% (v/v) to slightly higher than 9% (v/v). For this reason, it cannot complete fermentation, when alcohol reach levels higher than 12% (v/v), limiting their use in the industry. The objective of this work was to obtain new variants of T. delbrueckii with improved resistance to ethanol through adaptive laboratory evolution. Variants capable of tolerating ethanol levels of 11.5% (v/v) were obtained. These presented improved kinetic parameters, and additionally showed an increase in resistance to SO2 in ethanol compared to the original strain. Co-inoculated fermentations were performed with the original strain (FTd/Sc) and with the evolved strain (FTdF/Sc), in addition to a control fermentation using only Saccharomyces cerevisiae EC1118 (FSc). The results obtained show that FTdF/Sc present higher levels of 2-Ethylhexanol, compared to FTd/Sc and FSc. Furthermore, FTdF/Sc presents higher levels of total alcohols, total aldehydes, total phenolic derivatives, and total sulfur compounds with significant differences with FSc. These results provide a T. delbrueckii YCPUC10-F yeast with higher resistance to ethanol, which can be present throughout the fermentation process and be used in co-inoculated fermentations. This would positively impact the performance of T. delbrueckii by allowing it to be present not only in the early stages of fermentation but to remain until the end of fermentation.

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“…Moreover, GSH could contribute to the reduction of sulfur dioxide, which is used to prevent wine spoilage but can have a negative impact on consumer preference and flavor [ 4 ]. Accordingly, there is strong interest in developing novel wine yeast strains with enhanced GSH production [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

Genetic variation and expression changes associated with molybdate resistance from a glutathione producing wine strain of Saccharomyces cerevisiae

Mezzetti

Fay²,

Giudici

et al. 2017

PLoS ONE

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Glutathione (GSH) production during wine fermentation is a desirable trait as it can limit must and wine oxidation and protect various aromatic compounds. UMCC 2581 is a Saccharomyces cerevisiae wine strain with enhanced GSH content at the end of wine fermentation. This strain was previously derived by selection for molybdate resistance following a sexual cycle of UMCC 855 using an evolution-based strategy. In this study, we examined genetic and gene expression changes associated with the derivation of UMCC 2581. For genetic analysis we sporulated the diploid UMCC 855 parental strain and found four phenotype classes of segregants related to molybdate resistance, demonstrating the presence of segregating variation from the parental strain. Using bulk segregant analysis we mapped molybdate traits to two loci. By sequencing both the parental and evolved strain genomes we identified candidate mutations within the two regions as well as an extra copy of chromosome 1 in UMCC 2581. Combining the mapped loci with gene expression profiles of the evolved and parental strains we identified a number of candidate genes with genetic and/or gene expression changes that could underlie molybdate resistance and increased GSH levels. Our results provide insight into the genetic basis of GSH production relevant to winemaking and highlight the value of enhancing wine strains using existing variation present in wine strains.

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High-glutathione producing yeasts obtained by genetic improvement strategies: a focus on adaptive evolution approaches for novel wine strains

Cited by 28 publications

References 77 publications

Qualitative and quantitative screening of theβ-glucosidase activity inSaccharomyces cerevisiaeandSaccharomyces uvarumstrains isolated from refrigerated must

Qualitative and quantitative screening of theβ-glucosidase activity inSaccharomyces cerevisiaeandSaccharomyces uvarumstrains isolated from refrigerated must

Adaptive Laboratory Evolution of Native Torulaspora delbrueckii YCPUC10 With Enhanced Ethanol Resistance and Evaluation in Co-inoculated Fermentation

Genetic variation and expression changes associated with molybdate resistance from a glutathione producing wine strain of Saccharomyces cerevisiae

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