terclim by ICS banner
IVES 9 IVES Conference Series 9 Microbial ecosystems in wineries – molecular interactions between species and modelling of population dynamics

Microbial ecosystems in wineries – molecular interactions between species and modelling of population dynamics

Abstract

Microbial ecosystems are primary drivers of viticultural, oenological and other cellar-related processes such as wastewater treatment. Metagenomic datasets have broadly mapped the vast microbial species diversity of many of the relevant ecological niches within the broader wine environment, from vineyard soils to plants and grapes to fermentation. The data highlight that species identities and diversity significantly impact agronomic performance of vineyards as well as wine quality, but the complexity of these systems and of microbial growth dynamics has defeated attempts to offer actionable tools to guide or predict specific outcomes of ecosystem-based interventions. The application of such tools in future will depend on our understanding of the physiological and molecular drivers that govern microbial ecosystems. Here we describe several integrated approaches to characterize the molecular interactions between species within the fermentation and the waste-water ecosystem and to model the development of these ecosystems. Binary (two species) and consortia-based approaches indicate ecosystem-specific developmental patterns in these systems. On a molecular level, data strongly support that cell-wall related properties of yeast species impact the development of fermentation ecosystems during wine making and highlight the importance of physical contacts between species in these ecological processes. To model the wine yeast fermentation ecosystem, high-throughput flow cytometry-based approaches were developed, and specific models based on a machine-learning approach were developed. In winery wastewater, laboratory-based evolution of two species exposed to biotic selection pressure in a synthetic environment, Saccharomyces cerevisiae and the microalga Chlorella sorokiniana, identified two specific genes involved in carbon and nitrogen catabolite repression that facilitate mutualistic behaviors between yeast and microalgae when inactive. Taken together the data suggest novel strategies for microbial ecosystem-based decision making in wine making and improved integration of natural microbial biodiversity in the process.

DOI:

Publication date: February 11, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Florian F. Bauer, Cleo Conacher, Jennifer Oosthuizen, Georgia Strydom, Evodia Setati, Rene Naidoo-Blassoples

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

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

DETERMINATION OF FREE AMINO ACIDS, AMINO ACID POTENTIAL AND PROTEASE ACTIVITY IN THE LEES AND STILL WINES OF CHAMPAGNE

Prior to winemaking, organic or mineral nitrogen compound concentrations are usually measured in the vineyard and in grape musts. These indicators facilitate vine cultivation decisions, usually through yield or vigor. During vinification, yeast and bacteria metabolize nitrogen compounds in the musts in order to generate biomass. After fermentation, the microorganisms rerelease a part of this nitrogen as soluble compounds into the wines. Another part remains bound in the lees and can be lost during racking. The must’s natural nitrogen quantities, additional supplements during fermentation, and lees contact management enhance the release of nitrogen compounds to the wines. During ageing these nitrogen compounds – primarily the amino acids – are implicated in the generation of odorous compounds such as heterocycles(1).

Beyond liking scores: the importance of the drinking experience to understand our consumers

The presentation will approach the understanding of wine consumers´ perception based on the experiential model suggested by Warell (2008). In this framework, wine consumption gives rise to a
variety of experiences related to the perception, understanding, and judgment of the product. These
multidimensional facets of the drinking experience can be explored by measuring affective, cognitive,
and sensory responses of consumers, which are shown to be stable regardless of the social context.

EXPLORING RED WINE TYPICITY OF CORBIÈRES: EVALUATION OF THE DEGREE OF IMPACT OF VINIFICATION PROCESS ON THE CHEMICAL COMPOSITION AND ORGANOLEPTIC PROPERTIES OF WINES FROM DIFFERENT TERROIR

It is important nowadays for wine producers to create a product that is an expression of their terroir, a concept including the interaction between a place (topography, climate, soil), the people (tradition, winemaking and viticultural practices) and the resulting product (grape varieties, wines) [1]. Nonetheless, wine’s typicity linked to those terroirs must be easily recognizable by consumers thanks to distinctive sensory characters and composition [2]. Among the compounds of interest, aromatic compounds and polyphenols play an important role in the quality of red wines, by impacting on the odour, color and astringency. To explore the influence of terroir factors, including climate, soil and human practices, on the chemical and sensory profile of wines, red wines from five terroirs of the Corbières appellation were subjected to a general study approach.

RED WINE AGING THROUGH 1H-NMR METABOLOMICS

Premium red wines are often aged in oak barrel. This widespread winemaking process is used, among others, to provide roundness and complexity to the wine. The study of wine evolution during barrel aging is crucial to better ensure control of wine quality.
¹H-NMR has already been proved to be an efficient tool to monitor winemaking process [1]. Indeed, it is a non-destructive technique, it requires a small amount of sample and a short time of analysis, yet it provides clues about several chemical families.

WHAT’S FUTURE FOR SANTORINI’S VITICULTURE IN THE CONTEXT OF CLIMATE CHANGE

The own-rooted vineyard of Santorini is a unique case of vineyard worldwide that is been cultivated for thousands of years. On the island’s volcanic soil, the vines are still cultivated with traditional techniques, which are adapted to the specific and extreme weather conditions that prevail on it. While climate change is a reality in the Mediterranean region, will Santorini vineyard endure its impact? The study of the traditional training systems, techniques and vine density, as well as the application of sustainable solutions (cover crops and use of kaolin etc.) revealed sustainable methods for the adaptation of the local viticulture to new climatic phenomena that tend to be more and more frequent in the region due to climate change.