Macrowine 2021
IVES 9 IVES Conference Series 9 Improvement of non-Saccharomyces yeast dominance during must fermentation by using spontaneous mutants resistant to SO2, EtOH and high pressure of CO2

Improvement of non-Saccharomyces yeast dominance during must fermentation by using spontaneous mutants resistant to SO2, EtOH and high pressure of CO2

Abstract

AIM: A genetic study of four wine T. delbrueckii strains was done. Spore clones free of possible recessive growth‐retarding alleles with enhanced resistance to winemaking stressing conditions were obtained from these yeasts.

METHODS: The genetic marker of resistance to cycloheximide (cyhR) allows easy monitoring of the new mutants obtained from these yeasts. Identity of the high pressure resistant (HPR) mutants was verified by analysis of cell morphology, killer phenotype, cyhR marker, presence of viral dsRNA, RFLPs of mtDNA, and sequencing of Internal Transcribed Spacer ofribosomal DNA (ITS).

RESULTS: T. Delbrueckii mutants were isolated from some spore clones. Papillae resistant to SO2 were isolated. Subsequently, new spontaneous mutants capable of growing on YEPD plates with 10% ethanol were isolated. Rosé sparkling wine (cava) was made using these mutants. Two mutants, with the best fermentation kinetics and closest to the reference yeast Sc 85R4, were isolated from some bottles with high CO2 pressure and some were selected there after (Td MutHP41 and Td MutHP42). They had better fermentation kinetics and dominance than their parental yeast. Td MutHP41 showed great improvement for industrial base wine fermentation with respect to its parental yeast. Re-isolation and selection procedure to obtain new reinforced HPR mutants from previously selected HPR mutants was not a sound strategy to continue improving the fermentative capability of T. delbrueckii under high CO2 pressure. Continuous shaking during inocula preparation further improved the fermentative capability of T. delbrueckii yeasts.

CONCLUSIONS: Isolation of spontaneous mutants resistant to SO2 and ethanol seems to be a good strategy to slightly improve the fermentative efficiency of T. delbrueckii in must and base wine. The new mutants were genetically stable enough to be considered for industrial production, and their fermentative capability was further improved by continuously supplying oxygen during the conditioning stage before yeast culture inoculation in base wine.

DOI:

Publication date: September 10, 2021

Issue: Macrowine 2021

Type: Article

Authors

Alberto Martínez Brígido 1, Rocío Velázquez 1, Joaquín Bautista-Gallego 1, Emiliano Zamora 2, Manuel Ramírez 1

1 Departamento de Ciencias Biomédicas, Universidad de Extremadura, 06006 Badajoz, Spain.
2 Estación Enológica, Junta de Extremadura. 

Contact the author

Keywords

Torulaspora delbrueckii; wine fermentation, sporeclone; sparkling wine; ethanol resistance; SO2 resistance; pressure resistance

Citation

Related articles…

A applied viticultural zoning, based on the “secteurs de la reference” methodology, in the Cognac vineyard (France)

Dans les Charentes, en réponse à une crise de production du vignoble destiné à la production de Cognac, un plan de diversification viticole pour des vins de pays de qualité est mis en place. Il nécessite une connaissance des sols et de leurs caractéristiques viticoles pour orienter le choix des types de vins et adapter l’itinéraire technique de production.

Anthocyanin content and composition of Merlot grapes under temperature and late pruning conditions 

One of the main aspects of Climate Change is the increase of temperatures during summer and grape maturity period. Physiological processes are influenced by these high temperatures and result in grapes with higher sugar concentration, less acidity and less anthocyanin content among other quality changes. One strategy to deal with the climate change effects is the implementation of late winter pruning to alter the effect of high temperatures during key periods by delays in maturity time.

Amyndeon‐naoussa: the two faces of Xinomavro

Xinomavro is the most important indigenous red wine variety grown in Northern Greece. It participates in the production of several PGI wines in Macedonia while from 100% Xinomavro the PDO “Amyndeon” and “Naoussa” are produced. The viticultural area of Amyndeon lies in a plateau of 550 ‐700 m of altitude, in a semi‐continental climate with mostly deep sandy loamy soils derived from limestone and marl bedrocks while in Naoussa, Xinomavro is grown in a Mediterranean climate on more heavy textured soils, sandy clay loam to clay, derived from ophiolithic, limestone and marl bedrocks, in an altitude which varies from 150 to 400 m. Different soil, climate and viticultural technique interactions, result in great variability with respect to morphological, ampelographical and physiological characters of Xinomavro as well as in the characteristics of the wines produced. 

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

Revealing the origins of old bordeaux wines using terpene quantification

The overall quality of fine wines is linked to the development of “bouquet” during wine bottle ageing (1). Bordeaux red wine ageing bouquet is defined by the association of several odours