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…

LARGE SURVEY OF THE CHEMICAL COMPOSITION OF WINES RESULTING OF THE PRESSING OF RED WINE MARC. FIRST RESULTS

In the Bordeaux vineyards, press red wine represents about 15% of the volume of wines. Valuing this large volume of press wine is necessary from an economic point of view, of course, but also because of their organoleptic contribution to the blend. Nevertheless, there is a lack of recent knowledge on the composition of press wines. This work aims to establish an initial assessment of their composition (aromatic and polyphenolic) and to set up hypothesis on to the links with their sensorial identity.

HOW TO EVALUATE THE QUALITY OF NATURAL WINES?

The movement of Natural wines has clearly increased in the last few years, to reach a high demand from consumers nowadays. Switzerland has not been left out of this movement and has created a dedicated association in 2021. This association has the ambition to develop a specific tasting sheet for natural wines. The study of the tasting notes shows that the olfactory description of wines is recent but predominant today. But wine is a product makes to be drunk and not (just) to smell it. Based on these findings, a new 100-point tasting sheet has been developed. The main characteristics are 1) an evaluation in the mouth before the description of the olfaction, 2) to give 50% of the points on the judgment for the mouth characteristics, 3) to pejorate the visual aspects only if the wine is judged as “not drinkable” and 4) to express personal emotions.

SENSORY IMPROVEMENT OF DEALCOHOLISED WINES

Interest and willing-ness to buy alcohol-free wines by customers is increasing for several years [1]. Due to the rising relevance of dealcoholised wines it is the objective of this study to contribute to a better understanding of the flavor variation among dealcoholised wines and to explore enological measures, how to improve final quality.
First a range of commercial, alcoholfree white wines were analysed by the holistic sensory method projective mapping, including a question for hedonic acceptance. Based on the combination of a non-target-HS-SPME-GC/MS analysis with sensory analysis we obtained a clustering of the wines into three groups.

PESTICIDE RESIDUES IN THE VINEYARD ENVIRONMENTS: VINE LEAVES, GRAPE BERRIES, WINES, HONEYBEES AND ASIAN HORNETS

Synthetic pesticides are widely used in viticulture to ensure steady harvest quality and quantity. Fungicides are primarily used to control grapevine diseases but insecticides and herbicides are likewise used. Pesticide residues in viticultural areas currently represent a strong societal concern, but may also affect different trophic chains in such areas. In this project we wish to analyse honeybees collected from hives placed in different vineyards, their natural predator (the invasive hornet Vespa velutina), as well as the honey, grape berries, and wines produced.

SENSORY DEFINITION OF A TECHNICAL UNAVOIDABLE TRANSFER OF AROMA COMPOUNDS VIA SEALING IN A BOTTLING LINE IN ORDER TO PREVENT PROSECUTION DUE TO FRAUDULENT AROMATIZATION OF A SUBSEQUENTLY FILLED WINE

In 2020, 12% of all bottled German wines were aromatized, which may increase further due to rising popularity of dealcoholized wines. As sealing polymers of a bottling line absorb aroma compounds and may release them into regular wines in the next filling¹, this unintentional carry-over bears the risk to violate the legal ban of any aromatization of regular wine. However, following EU legislation, German food control authorities accept a technical unavoidable transfer of aroma compounds, if this is of no sensory significance.