Contribution of soil for tipifiyng wines in four geographical indications at Serra Gaúcha, Brazil

Bacillus velezensis and Trichoderma harzianum are relevant microorganisms used in viticulture as biocontrol agents against pathogens of trunk (e.g. Phaeoacremonium minimum), leaves (e.g. Plasmopara viticola) or fruit (e.g. Botrytis cinerea), or as biostimulants, improving the resilience of plants against biotic or abiotic stressors through different direct and non-direct interactions.
In this biotechnological approach, formulation plays a crucial role. Controlling water activity in the product, thus stabilising microbial viability is key to ensuring effective application. We present the benefits of the citrate ester CITROFOL® AI (triethyl citrate) as a novel bio-based carrier liquid in microbial formulations. CITROFOL® AI is safe for humans and the environment, thus offering a promising base for sustainable treatments in viticulture.

In a recent study several genes controlling the acidification properties of the wine yeast Saccharomyces cerevisiae have been identified by a QTL approach [1]. Many of these genes showed allelic variations that affect the metabolism of malic acid and the pH homeostasis during the alcoholic fermentation. Such alleles have been used for driving genetic selection of new S. cerevisiae starters that may conversely acidify or deacidify the wine by producing or consuming large amount of malic acid [2]. This particular feature drastically modulates the final pH of wine with difference of 0.5 units between the two groups.

During a three-year period, the vineyards of the Carnuntum wine district are investigated for their terroir characteristics. The interdisciplinary study is aimed at the description of the physiogeographic

Fumaric acid has been approved by the OIV in 2021 for its application on wine to control the growth and activity of lactic acid bacteria. Fumaric acid is currently being evaluated by the OIV as an acidifier of must and wine. Investigations during the 2023 vintage provided further information on its use on must or during AF, thus completing information provided during the previous vintage.

A great variability in the amount of polysaccharides recovered at the end of fermentations carried out by pure cultures of 89 non-Saccharomyces yeasts was observed. The utilization of the best polysaccharides producers in mixed cultures with S. cerevisiae resulted in considerable increases in the final concentration of polysaccharides and showed a strain dependent effect on glycerol production as compared to pure culture of S. cerevisiae.