Addition of glutathione-rich inactivated yeasts to white musts: effects on wine composition and sensory quality

The foliar application of urea has been shown to be able to satisfy the specific nutritional needs of the vine as well as to increase the nitrogen composition of the must. On the other hand, the use of nanotechnology could be of great interest in viticulture as it would help to slow down the release of urea and protect it against possible degradation. Several studies indicate that cell wall synthesis and remodeling are affected by nitrogen availability.

‘Tempranillo Tinto’ is a black-berried Iberian cultivar that originated from a hybridization between cvs. ‘Benedicto’ and ‘Albillo Mayor’ [1]. Today, it is the third most widely grown wine grape cultivar worldwide with more than 200,000 hectares of vineyards mostly distributed along the Iberian Peninsula, where it is also known as ‘Cencibel’, ‘Tinta de Toro’, ‘Tinta Roriz’, and ‘Aragonez’, among other synonyms. Here, we quantified the intra-varietal genomic diversity in this cultivar through the study of 35 clones or ancient vines from seven different Iberian wine-making regions. A comparative analysis after Illumina whole-genome sequencing revealed the presence of 1,120 clonal single nucleotide variants (SNVs).

The study conducted various fermentations of different grape juices using various strains of Lachancea thermotolerans and one strain of Saccharomyces cerevisiae. Because of the new conditions caused by climate change, wine acidity must be influenced as well as the volatile profile. Non-Saccharomyces yeasts such as L. thermotolerans are real options to mitigate the impact of climate change in wine production.

Melatonin is a bioactive compound with antioxidant properties, that has been found in many fermented beverages, such as beer and wine [1]. Indeed, it has been shown that yeast can synthesize melatonin during alcoholic fermentation, although its role inside the cell, as well as the metabolic pathway involved in its synthesis, is still unclear [1]. Recent studies showed that during fermentation, melatonin interacts with different proteins of the glycolytic pathway in both Saccharomyces and non-Saccharomyces yeast, for instance glyceraldehyde 3-phosphate dehydrogenase, pyruvate kinase or enolase [2].

Crops are facing increasing biotic and abiotic stress pressures due to global changes. However, trade-off mechanisms between these stresses and the underlying physiological processes are still poorly understood, especially in perennial crop species. To better understand these trade-offs, we studied the effect of drought on grapevine (Vitis vinifera) physiology and esca-related wood fungal communities. Esca is a vascular disease caused by a community of wood-infecting pathogenic fungi, and characterized by trunk necrosis, leaf scorch symptoms, yield losses, and mortality.