Selection of beneficial endophytes from Sicilian grapevine germplasm 

A 3-year study was carried out in order to evaluate the ecophysiology, yield and quality characteristics of Vitis vinifera L. cv. Kékfrankos (syn. Limberger) at Eger-Nagyeged hill (steep slope) and at Eger-Kőlyuktető (flat) vineyard sites located in the Eger wine region, Hungary.

Yeast species S. cerevisiae, S. uvarum, S. kudriavzevii and their hybrids present clear metabolic differences, even when we compared S. cerevisiae wine versus wild strain. These species and hybrids produced significantly higher amounts of glycerol, organic acids, 2,3-butanediol, and 2-phenyl ethanol and a reduction of the ethanol yield, properties very interesting in the sector to deal with climate change effects. To understand the existing differences, we have used several omics techniques to analyze the dynamics of the (intra- and extracellular) metabolomes and/or transcriptomes of representative strains of S. cerevisiae, S. uvarum, S. kudriavzevii, and hybrids.

Extraction of anthocyanins and tannins have been studied for two grape varieties, Carignan and Grenache, two maturation levels and two vintages, in model solutions and in wines, using UHPLC-MS/MS in the MRM mode  and HPSEC.

From the beginning of the yeast autolysis process, several interesting intracellular and cell wall constituyents are released to the media providing different characteristics to the wine, being this process extensively studied in sparkling wines due to their important contribution to their properties (1-2). Yeast derived products (YDs) try to emulate the natural yeast autolysis compounds release enhancing the organoleptic characteristics of resulting wines (2-3). This study is a comprehensive evaluation of the impact of the addition of different YDs added to base wine on the chemical, physical and sensory characteristics of the resulting sparkling wines. METHODS: Chardonnay base wine was employed to carry out this study. Three experimental YDs were added at 5 and 10 g/hL to the tirage liqueur: a yeast autolysate (YA), a yeast protein extract (PE) and an inactivated dry yeast from Torulaspora delbrueckii, (TD), and two commercial specific inactivated dry yeast: OPTIMUM WHITE® (OW) and PURE-LONGEVITY®(PL). After second fermentation, measurements were carried out after 3, 6, 9 and 18 months of aging on lees. General enological parameters, proteins, polysaccharides (HPLC-DAD-RID), volatile compounds profile (GC-MS), foaming characteristics (Mosalux), and descriptive sensory analyses were carried out.

Just over 150 years ago, phylloxera, daktulosphaera vitifoliae, was introduced to europe, and particularly france, from north america via imports of american vitis plants. This aphid, with its complex biology and life cycle, has spread rapidly to most vineyards, causing rapid and lethal decline of v. Vinifera vines due to the primary and secondary damage it causes to the roots. In response to this pest, and given the economic importance of the french wine sector, professional representatives organised into ‘agricultural societies’, scientists and public authorities rallied together to identify the exact causes, seek solutions and try to stem the serious socio-economic crisis that ensued.