Oenococcus oeni clonal diversity in the carbonic maceration winemaking

Since the mid-1980s, several surveys have been carried out in La Rioja to search for populations of the sylvestris grapevine subspecies (Vitis vinifera L. subsp. sylvestris Gmelin). The banks of the Ebro River and its tributaries (Alhama, Cidacos, Leza, Iregua, Najerilla, Oja and Tirón rivers), as well as the surrounding vegetation of their valleys have been covered. So far, all the populations found are alluvial, forming part of the riparian vegetation of the Najerilla (the first reported population in La Rioja [1]), Iregua, and the vicinity of Oja valleys.

Bobal is the second most widely grown Spanish red grape variety (54,165 has), mainly cultivated in the Valencian Community and especially, in Utiel-Requena region (about 67% of 34,000 has). In this study, agronomic and enological parameters were determined in 98 biotypes selected during 2018 and 2019 in more than 50 vineyards over 50 years-old in the Utiel-Requena region. Moreover, a multi-criteria approach considering temperature and rainfall (Fig. 1A), among other parameters, was made to establish three different zones within the region (Fig. 1B), where in the future the selected biotypes will evaluated. In fact, in 2020, 4 replicates and 12 vines per biotype were planted in an experimental vineyard to preserve this important intra-cultivar diversity.

Mannoproteins are released at the end of alcoholic fermentation due to yeast autolysis [1]. It has been described a positive effect of these molecules on lactic acid bacteria growth [2]. The main objective of this work was the characterization of different mannoproteins extracted from active dry yeast (ADY) and the assessment of their effect on Oenococcus oeni and malolactic fermentation (MLF).

The Agenda 2030 of the EU sets out the main guidelines for transitioning towards a resilient, green and safe economy. To this regard, the wine sector is experiencing an ecological transition in different ways such as increasing the production of ecological crops, or promoting the production of wines under more environmental-friendly and healthier (i.e., lower levels of SO2) products. These alternatives to conventional production are a smaller proportion of wines, in constant growth and demand, and follow alternative and minority practices, which range from sustainable to deeply philosophical thoughts. Among these methods there are organic, biodynamic and, more recently, natural wines.

Cover cropping in vineyard is a sustainable and alternative soil management system to conventional tillage that is gaining more and more importance among winegrowers and is being promoted, among other organizations, by the European Union through the eco-schemes of the Common Agricultural Policy.
However, the use of cover crops in Mediterranean viticultural environments is conditioned, to a large extent, by the availability of irrigation water which, in a context of global warming like the one we are experiencing, must be adjusted to savings strategies, supplying to the vine only what it needs in each moment.