Browsing by Author "Ceppi de Lecco, Consuelo"

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    Characterization of Cabernet Sauvignon from Maipo Valley (Chile) Using Fluorescence Measurement
    (2023) Ceppi de Lecco, Consuelo; Canon Amengual, Pablo
    Virus infection in Vitis vinifera negatively impacts vineyard production and grape quality. Examples are grapevine leafroll-associated viruses (GLRaVs) and grapevine rupestris stem pitting-associated viruses (GRSPaV). We investigated transient fluorescence of chlorophyll a in leaves of Cabernet Sauvignon, the primary red cultivar planted in Chile, using the OJIV test. First, we evaluated fluorescence in productive grapevines throughout their development, and then we analyzed the same parameters in plants infected with GLRaVs or GLRaVs+GRSPaV. We observed that throughout phenological development, as in the virus-affected clones, the kinetics of fluorescence emission decreased, particularly in values such as F-o and F-M, reflecting the limitation in electron donation by the oxygen-releasing complexes and changes in the PSII antenna complex. The parameter reflecting the most significant differences was the performance index (PIABS), whose value decreases throughout phenological development and is also lower in virus-affected plants compared to healthy plants. This decrease would indicate that PSII changes the conversion of light energy of chemical energy to heat dissipation, making PIABS an excellent parameter to evaluate the vitality of Cabernet Sauvignon vineyards.
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    Screening and Selection of Native Lactic Acid Bacteria Isolated from Chilean Grapes
    (Multidisciplinary Digital Publishing Institute (MDPI), 2025) Vargas Luna, Carla; Godoy, Liliana; Benavides, Sergio; Ceppi de Lecco, Consuelo; Urtubia, Alejandra; Franco, Wendy
    © 2025 by the authors.The aim of this study was investigating the biological diversity of lactic acid bacteria isolated from Chilean grapes and identifying potential candidates for use as malolactic fermentation starter cultures. The isolated bacteria underwent a comprehensive six-stage screening process, which was mutually exclusive except for the evaluation of tyramine production and citric acid intake. This process included morphological, metabolic, fermentation yield, and resistance tests to identify promising malolactic strains. Morphological assessments led to the selection of 23 isolates, which were genetically identified as Levilactobacillus brevis (65% abundance) and Leuconostoc mesenteroides (35% abundance). Among these, eight strains exhibited low sugar metabolism rates, while three demonstrated competitive growth and malolactic activity in a synthetic medium containing 10% ethanol, outperforming a commercial strain. Low consumption was observed in the qualitative citric acid intake test, whereas a positive response was noted for tyramine production. At the conclusion of the sequential selection criteria, Levilactobacillus brevis BCV-46 exhibited the most favorable characteristics for potential use as a malolactic starter culture, successfully withstanding the combined stress factors of ethanol, pH, and SO2.