Bacterial fertilizers based on rhizobium laguerreae and bacillus halotolerans enhance cichorium endivia L. phenolic compound and mineral contents and plant development

[EN] Today there is an urgent need to find new ways to satisfy the current and growing food demand and to maintain crop protection and food safety. One of the most promising changes is the replacement of chemical fertilizers with biofertilizers, which include plant root-associated beneficial bacteria. This work describes and shows the use of B. halotolerans SCCPVE07 and R. laguerreae PEPV40 strains as efficient biofertilizers for escarole crops, horticultural species that are widely cultivated. An in silico genome study was performed where coding genes related to plant growth promoting (PGP) mechanisms or different enzymes implicated in the metabolism of phenolic compounds were identified. An efficient bacterial root colonization process was also analyzed through fluorescence microscopy. SCCPVE07 and PEPV40 promote plant development under normal conditions and saline stress. Moreover, inoculated escarole plants showed not only an increase in potassium, iron and magnesium content but also a significant improvement in protocatechuic acid, caffeic acid or kaempferol 3-O-glucuronide plant content. Our results show for the first time the beneficial effects in plant development and the food quality of escarole crops and highlight a potential and hopeful change in the current agricultural system even under saline stress, one of the major non-biological stresses.[ES] Hoy en día existe una necesidad urgente de encontrar nuevas formas de satisfacer la actual y creciente demanda de alimentos y mantener la protección de los cultivos y la seguridad alimentaria. Uno de los cambios más prometedores es la de los fertilizantes químicos por biofertilizantes, que incluyen bacterias beneficiosas asociadas a las raíces de las plantas. Este trabajo describe y muestra el uso de las cepas B. halotolerans SCCPVE07 y R. laguerreae PEPV40 como biofertilizantes eficientes para los cultivos de escarola, especies hortícolas ampliamente cultivadas. Se realizó un estudio genómico in silico en el que se codificaron genes relacionados con los mecanismos de promoción del crecimiento vegetal (PGP) o con diferentes enzimas implicadas en el metabolismo de compuestos fenólicos. También se analizó el proceso de colonización bacteriana de las raíces mediante microscopía de fluorescencia. SCCPVE07 y PEPV40 promueven el desarrollo de la planta en condiciones normales y estrés salino. Además, las plantas de escarola inoculadas mostraron no sólo un aumento en el contenido de potasio, hierro y magnesio, sino también una mejora significativa en el contenido de ácido protocatechuico, ácido cafeico o kaempferol 3-O-glucurónido. Nuestros resultados muestran por primera vez los efectos beneficiosos en desarrollo de la planta y la calidad alimentaria de los cultivos de escarola y ponen de manifiesto un cambio potencial y esperanzador en el sistema agrícola actual, incluso bajo estrés salino, uno de los principales estreses no biológicos. Traducción realizada con la versión gratuita del traductor www.DeepL.com/Translato

Development of a fractionation method for the detection and identification of oak ellagitannins in red wines

[ES] During maturation and ageing in oak barrels wines improve their organoleptic properties. Ellagitannins can be released from wood to the wine and be involved in oxidation reactions and seem to influence the astringency and colour properties of the wine. Nevertheless, the ellagitannins levels are lower than those of other wine constituents and, consequently, they are not easily detected. This study has developed a two-step fractionation method consisting of a solid phase extraction in C-18 Sep-Pak® cartridges followed by size exclusion chromatography in hand-packed Sephadex LH-20 minicolumn for the detection of oak ellagitannins in different types of wines. An HPLC method has also been developed which allows the separation of compounds with the same m/z ratios, facilitating the ellagitannin identification by means of the mass spectrometric analyses. The main oak ellagitannins (grandinin, vescalagin, roburin E and castalagin) were isolated, detected separately and identified in a spiked wine and in three real ones, proving the usefulness of the fractionation method

Elaboración de un protocolo de determinación de micronutrientes para su implamentación en la docencia práctica

Memoria ID-169. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2018-2019

Study of phenolic markers for the differentiation of wines made with Vitis vinifera L. cv Rufete grapes.

The "D.O.P. Sierra de Salamanca" has been related, since its establishment, to the production of wines made with Vitis Vinifera L. cv Rufete grapes, an autochthonous grape from La Sierra de Francia. The production of this type of wine has been recently relaunched due to consumers' demand for new wines different from world standards and due to its potentially greater adaptation to an scenario of climate change. This study aims at establishing the phenolic composition of wines made with 100% Rufete grapes from the D.O.P Sierra de Salamanca, as well as establishing a comparison between the phenolic composition and the chromatic characteristics of these wines with commercial wines made with mixtures of Rufete and Tempranillo grapes in different proportions. The HPLC-DAD-MSn analysis of wine samples from three different wineries from the D.O.P allowed the identification of 35 different anthocyanin-derived pigments, 63 flavanols and 11 flavonols. From the phenolic composition and by means of principal component analysis (PCA), it has been possible to establish differences between the different wines depending on the vintage, the winery and the variety of grape.La Denominación de Origen Protegida (D.O.P.) Sierra de Salamanca siempre ha estado vinculada desde su fundación a la elaboración de vinos con uvas Vitis Vinifera L. variedad Rufete, una uva autóctona de la Sierra de Francia. Su producción en los últimos años se ha visto relanzada debido a la demanda por parte de los consumidores de nuevos vinos, diferentes a los estándares mundiales, y por su potencial de adaptación a un escenario de cambio climático. Con este estudio se pretende establecer la composición fenólica de vinos elaborados con uvas 100 % Rufete de la D.O.P Sierra de Salamanca, así como establecer una comparación de dicha composición fenólica y de las características cromáticas de los mismos con las de vinos comerciales elaborados con mezclas de uva variedad Rufete y variedad Tempranillo, en distintas proporciones. El análisis mediante HPLC-DAD-MSn de muestras de vinos procedentes de tres bodegas distintas de la D.O.P permitió identificar 35 pigmentos de naturaleza antociánica, 63 flavanoles y 11 flavonoles diferentes. A partir de la composición determinada y mediante análisis de componentes principales (PCA) se ha podido establecer diferencias entre las distintas muestras en función del año de producción, la bodega y la variedad de uva empleada

Diseño e implementación de píldoras formativas con autoevaluación mediante Kaltura como una nueva metodología para mejorar el aprendizaje

Memoria ID2022-197 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2022-2023

Color Stabilization of Red Wines. A Chemical and Colloidal Approach

Este artículo es parte del International Workshop on Anthocyanins (IWA2013)[EN]The effects of cold treatment and time on CIELAB color parameters and on anthocyanin and anthocyanin-derived pigments composition have been evaluated as has been the effectiveness of either an enological tannin or a mannoprotein (M) on their stabilization. With respect to color, hue (hab) was increased in the wines treated with both enological products. Furthermore, the color changes induced by cold treatment were lessened by the addition of these two enological products, although the protective effect was higher for the wines treated with M. The pigment analysis revealed higher percentages of anthocyanin-derived pigments in tannin and M-treated samples (in both cold treated and not) in relation to control ones. The addition of the enological tannin may favor the synthesis of anthocyanin-derived pigments, which are chemically more stable than native anthocyanins, whereas M seems to stabilize anthocyanin-derived pigments from a colloidal point of view, avoiding their aggregation and further precipitation

Effect of the addition of flavan-3-ols on the HPLC-DAD salivary-protein profile

[EN] The interaction between monomeric flavan-3-ols and salivary proteins has been studied using HPLC-DAD. A chromatographic method has been described and seven protein fractions were collected. The peptides and proteins present in each fraction have been identified using nLC-MS-MS analysis. The interaction between saliva and catechin, epicatechin and gallocatechin has been studied. These compounds interact in a discriminated way with salivary proteins: catechin causes a decrease of some fractions, epicatechin causes the decrease or increase of fractions while gallocatechin seems to cause an increase of two fractions. This variable behavior is explained, for the decrease in the chromatographic area, by the precipitation of salivary proteins and, for the increase of the area, by the formation of soluble complexes and/or for the formation of new peaks

Hemisynthesis and Structural and Chromatic Characterization of Delphinidin 3-O-Glucoside–Vescalagin Hybrid Pigments

[EN] During red wine maturation in the presence of oak wood, reactions involving anthocyanins and ellagitannins might affect wine organoleptic properties such as color and astringency. In this work, the condensation reaction between myrtillin (delphinidin 3-O-glucoside) and vescalagin has been performed to determine the behavior of this anthocyanin in this kind of reaction and to assess the possible impact of such a reaction in wine color modulation. Two different hybrid pigments have been hemisynthetized and characterized by HPLC-DAD-MS and NMR spectroscopy. These pigments have been identified as 1-deoxyvescalagin-(1β→8)-myrtillin (major) and 1-deoxyvescalagin-(1β→6)-myrtillin (minor). The minor pigment could be formed both by the condensation reaction and by a regioisomerization process from the major pigment. Moreover, the chromatic properties of these pigments have been studied and compared to those of myrtillin. The hybrid pigments showed an important bathochromic shift (ca. 20 nm) in the maximum absorbance wavelength and lower molar absorption coefficients

Thermodynamic and Kinetic Properties of a New Myrtillin–Vescalagin Hybrid Pigment

[EN] During red wine maturation in contact with oak wood, C-glucosidic ellagitannins can react with anthocyanins, leading to new pigments. In this work the thermodynamic and kinetic constants of the network pH-dependent equilibrium of a new myrtillin (delphinidin 3-O-glucoside)−vescalagin hybrid pigment (1-deoxyvescalagin-(1β→8)-myrtillin) have been determined by UV−visible absorption and stopped-flow experiments and compared to those determined for myrtillin. The vescalagin substitution at the C-8′ center of myrtillin entails important variations in the pigment behavior upon pH changes. The hybrid pigment showed lower pK′a and pKa values and a much higher value of Kt. As a consequence, at moderately acidic pH values (4 < pH < 6), the percentage of the hemiketal is much lower and the quinoidal base and the (E)-chalcone represent higher percentages relative to those for myrtillin. Therefore, the hybrid pigment can provide in slightly acidic or neutral solutions an exceptionally different color compared to that of myrtillin