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:
Issue: OENO Macrowine 2023
Type: Article
Authors
South African Grape and Wine Research Institute, Department of Viticulture and Oenology, Stellenbosch University, Stellenbosch, South Africa