Influence of different Lachancea thermotolerans strains in wine acidity

Calcium (Ca) is an important nutrient for plants which plays key signaling and structural roles. It has been observed that exogenous Ca application favors the pectin accumulation and inhibition of polygalacturonase enzymes, minimizing fruit spoilage. Silicon (Si) is a non-essential element which has been found to be beneficial for improving crop yield and quality, as well as plant tolerance to diverse abiotic and biotic stress factors. The effect of Si supply to grapevine has been assessed in few investigations, which reported positive changes in grape quality and must composition.

The projected rise in mean air temperatures together with the frequency, intensity, and length of heat waves in many wine-growing regions worldwide will deeply impact grape berry development and quality. Several studies have been conducted and a large set of molecular data was produced to better understand the impact of high temperatures on grape berry development and metabolism[1]. According to these data, it is highly likely that the metabolomic dynamics could be strongly modulated by heat stress (HS).

Volatile organic compounds (VOCs) constitute a diverse group of secondary metabolites key for the communication of plants with other organisms and for their adaptation to environmental and biotic stresses. The emission of these compounds through leaves is also affected by the interaction of plants with symbiotic microorganisms, arbuscular mycorrhizal fungi (AMF) among them [1]. Our objective was to know the concentration and profile of VOCs emitted by the leaves of two grapevine varieties (Tempranillo, T, and Cabernet Sauvignon, CS, grafted onto R110 rootstocks), inoculated or not with a consortium of five AMF (Rhizophagus irregularis, Funneliformis mosseae, Septoglomus deserticola, Claroideoglomus claroideum and C. etunicatum).

Pomace is one of the main residues generated by the wine industry and represents an environmental problem. Currently, there is a growing interest in the revaluation of these products because different bioactive compounds can be obtained from them, such as polyphenols, grape seed oils and polysaccharides. Red grape pomace can be an important source of polysaccharides, but they are currently little studied and even less with viable and environmental extraction processes (green extraction), such as flash extraction. The residual amount of the fraction rich in pectin (residual pulp) and component rich in hemicellulose in the pomace and the strength of association of the pectin with the cellulose-xyloglucan network depend on the degree of extractability of the polysaccharides in red winemaking and on the winemaking conditions.

Bacterial antibiotic resistance is a major current health problem. Polyphenols have demonstrated antibacterial activity, and in this work we studied the effect of oenological polyphenols on the growth of intestinal multidrug-resistant strains of human and animal origin. Two Enterococcus faecium strains, resistant to vancomycin and other antibiotics, and four Escherichia coli strains, resistant to ampicillin and other antibiotics, were included in this study. All strains showed multidrug resistant phenotypes and genotypes to at least two antibiotic families.