Design of microbial consortia to improve the production of aromatic amino acid derived compounds during wine fermentation

Brettanomyces is a world-renowned yeast that negatively impacts the chemical composition of wines through the production of metabolites that negatively impact the sensory properties of the final product. Its resilience in wine conditions and ability to produce off-flavors make it a challenge for winemakers. Currently, the primary control technique involves adding sulfur dioxide (SO2); however, some Brettanomyces strains are developing resistance to this preservative agent. [1] Therefore, new management strategies are necessary to control this spoilage yeast.

The use of cover crops under the vines might be an alternative to the use of herbicides or tillage, improving grapevine quality and soil characteristics. The aim of this research was to study the implications of different management strategies of the soil under the vines (herbicide, cultivation or cover crops) on grapevine growth, water and nutritional status, gas exchange parameters and belowground microbial communities.
The experimental design consisted in 4 treatments applied on 35L-potted Tempranillo vegetative grapevines with 10 replicates each grown in an open-top greenhouse in 2022 and 2023. Treatments included two cover crop species (Trifolium fragiferum and Bromus repens), herbicide (glyphosate al 36%) and an untreated control.

Trichoderma is one of the most widely used fungal biocontrol agents on vineyards due to its multiple benefits on this crop, such as its fungicidal and growth promoting capacity. In this work, we have analyzed the effect on the concentration of nutrients in grapevine leaves and on the quality of the grape must after spraying an autochthonous strain of Trichoderma harzianum and one of the main secondary metabolites produced by this genus, 6-pentyl-α-pyrone (6PP).

Rootstocks not only provide tolerance to Phylloxera, but also ensure the supply of water and mineral nutrients to the whole plant. Rootstocks are an important way of adapting to environmental conditions while conserving the typical features of scion varieties. We can exploit the large diversity of rootstocks used worldwide to aid this adaptation. The aim of this study was to characterise rootstock regulation of scion mineral status and its relation with scion development.

Traditional drought tolerant varieties such as Cabernet Sauvignon, Monastrell, and Syrah [1], have been used as parents in the grapevine breeding program initiated by the Instituto Murciano de Investigación y Desarrollo Agrario y Medioambiental (IMIDA) in 1997 [2]. This work presents the results of evaluating three new genotypes obtained from crosses between ‘Monastrell’ and ‘Cabernet Sauvignon’ (MC16 and MC80) and between ‘Monastrell’ and ‘Syrah’ (MS104), comparing their performance under conditions of water scarcity and high temperatures with that of their respective parental varieties. For this purpose, the six genotypes were cultivated under controlled irrigation conditions (60% ETc) and rainfed conditions.