WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 3 - WAC - Oral 9 The wine microbial ecosystem: Molecular interactions between yeast species and evidence for higher order interactions

The wine microbial ecosystem: Molecular interactions between yeast species and evidence for higher order interactions

Abstract

Fermenting grape juice represents one of the oldest continuously maintained anthropogenic microbial environments and supports a well-mapped microbial ecosystem. Several yeast and bacterial species dominate this ecosystem, and some of these species are part of the globally most studied and best understood individual organisms. Detailed physiological, cellular and molecular data have been generated on these individual species and have helped elucidate complex evolutionary processes such as the domestication of wine yeast strains of the species Saccharomyces cerevisiae. These data support the notion that the wine making environment represents an ecological niche of significant evolutionary relevance. Taken together, the data suggest that the wine fermentation ecosystem is an excellent model to study fundamental questions about the working of microbial ecosystems and on the impact of biotic selection pressures on microbial ecosystem functioning. Indeed, and although well mapped, the rules and molecular mechanisms that govern the interactions between microbial species within this, and other, ecosystems remain underexplored. Here we present data derived from several converging approaches, including microbiome data of spontaneous fermentations, the population dynamics of constructed consortia, the application of biotic selection pressures in directed laboratory evolution, and the physiological and molecular analysis of pairwise and higher order interactions between yeast species. The data reveal the importance of cell wall-related elements in interspecies interactions and in evolutionary adaptation and suggest that predictive modelling and biotechnological control of the wine ecosystem during fermentation are promising strategies for wine making in future.

DOI:

Publication date: June 13, 2022

Issue: WAC 2022

Type: Article

Authors

Cleo Conacher, Florian F. Bauer, Natasha Luyt, Bryan K. Mundia, Mathabatha E. Setati, Debra Rossouw

Presenting author

Cleo Conacher | South African Grape and Wine Research Institute, Department of Viticulture and Oenology, Stellenbosch University

South African Grape and Wine Research Institute, Department of Viticulture and Oenology, Stellenbosch University

Contact the author

Keywords

Fermentation ecosystem, dominant yeast species, interactions, consortia, gene expression

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

Diagnosis of soil quality and evaluation of the impact of viticultural practices on soil biodiversity in a Southwestern France vineyard

The soil plays a pivotal role in the agroecological transition processes, due to its numerous implications in production support, water regulation, air and nutrient supply, and its function of reservoir for the major part of planet biodiversity. Therefore, soil quality and adequate soil management are key levers for an ecologically and economically sustainable viticulture. Gascogn’Innov (2017-2022) is an Operational Group funded by the European Innovation Partnership for Agriculture. As such, it gathered winegrowers from the south-west of France (Gascony), scientists, advisors and technicians, around a project focused on the biological functioning of viticultural soil and the design of better-adapted technical paths for soil protection.

Aroma compounds involved in the fruity notes of red wines potentially adapted to climate change.

Currently, climate change represents one of the major issues for the wine sector. The increasing temperature already recorded and expected in the upcoming years reduce the vegetative cycle of the grape varieties planted in Bordeaux area, affecting the physicochemical parameters of grapes and consequently, the quality of wine. From a sensory point of view, the attenuation of the fresh fruity character in some varietals is accompanied by the accentuation of dried-fruit notes [1]. As a new adaptive and ecological strategy on global warming, some winegrowers have initiated changes in the Bordeaux blend of vine varieties using late-ripening grape varieties [2]. 

REMEDIATION OF SMOKE TAINTED WINE USING MOLECULARLY IMPRINTED POLYMERS

In recent years, vineyards in Australia, the US, Canada, Chile, South Africa and Europe have been exposed to smoke from wildfires. Wines made from smoke-affected grapes often exhibit unpleasant smoky, ashy characters, attributed to the presence of smoke-derived volatile compounds, including volatile phenols (which occur in free and glycosylated forms). Various strategies for remediation of smoke tainted wine have been evaluated. The most effective strategies involve the removal of smoke taint compounds via the addition of adsorbent materials such as activated carbon, which can either be added directly or used in combination with nanofiltration. However, these treatments often simultaneously remove wine constituents responsible for desirable aroma, flavour and colour attributes.

Impact of press fractioning on Pinot noir and Pinot meunier grape juice and wine compositions and colour

The separation of different grape juice press fractions is an important step in the production of sparkling base wines. A complete press cycle for this style of wine is a series of pressure increases (squeezes) resulting in variations in juice composition during the press cycle. After alcoholic fermentation, wines obtained from grape juices also exhibit strong differences for numerous characteristics. Nevertheless, there is no statistical study of the impact of the press cycle on grape juices and wine colour/composition. So, the aim of this study (vintage 2018) was to investigate the changes in composition and colour parameters of Pinot noir and Pinot meunier grapes juices, as well as their corresponding wines, during the pressing cycle.

Influence of pedoclimatic factors during berry ripening in Burgundy

Berry composition at ripeness can be explained by many factors. This study was carried out from 2004 through 2011 in a 60 block network in the Yonne region, Burgundy.