Browsing by Author "Godoy Olivares, Liliana"
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- ItemCell wall modifications in Saccharomyces cerevisiae wine yeast through adaptive laboratory evolution with Tebuconazole(2025) Becerra Bevensee, Kevin Andrew; Plaza, Verónica; Castillo, Luis; Godoy Olivares, LilianaSaccharomyces cerevisiae is the most used yeast for wine production around the world. Several characteristics make this yeast the wine yeast of excellence; among them is a great tolerance to higher concentrations of sugar and alcohol. Nevertheless, some compounds could have detrimental effects on its development like pesticides. Tebuconazole is one of the most common fungicides used in agriculture, belonging to the largest group of fungicides, the triazoles chemical group, that act on sterol biosynthesis. Yeasts have different responses to compensate for stress, and changes in their cell wall are one of the main ones. This work aimed to obtain new variants of S. cerevisiae through adaptive laboratory evolution (ALE) using Tebuconazole as selection pressure and to evaluate changes in yeast cell wall structure, composition, and fermentative behavior. Three new variants of S. cerevisiae were obtained. Analysis of the relative expression of genes associated with cell wall components showed that the third variant obtained YCPUC209C, had overexpression of genes FKS1, FKS3, CHS3, and SED1 in comparison with the original strain, also morphological analysis through TEM microscopy showed that YCPUC209C had an increase of 22.2% of cell wall thickness and 19% increase in the amount of glucan in comparison to the original strain. These cell wall changes were accompanied by hypersensitive to β-1,3-glucanase activity. Increased tolerance to pesticides Buprofezin and Spirotetramat presence during alcoholic fermentation was achieved by YCPUC209C, improving fermentative efficiency parameter. Changes in cell wall structure and composition reported in this work open new lines of analysis like the evaluation of yeast pesticide dissipation capacity since it is reported that components, such as glucan and chitin, can bond to these contaminants, reducing their residues in the wine.
- ItemCorrection to: Screening for indole-3-acetic acid synthesis and 1-aminocyclopropane-carboxylate deaminase activity in soil yeasts from Chile uncovers Solicoccozyma terrea as an effective plant growth promoter(2025) Carvajal Contardo, Mariajosé; Godoy Olivares, Liliana; Gebauer Hernández, Marlene Gloria; Catrileo Aros, Daniela Francisca; Albornoz Gutiérrez, Francisco Javier
- ItemCorrection to: Screening for indole-3-acetic acid synthesis and 1-aminocyclopropane-carboxylate deaminase activity in soil yeasts from Chile uncovers Solicoccozyma terrea as an effective plant growth promoter(2025) Carvajal Contardo, Mariajosé; Godoy Olivares, Liliana; Gebauer Hernández, Marlene Gloria; Catrileo Aros, Daniela Francisca; Albornoz Gutiérrez, Francisco Javier
- ItemSolicoccozyma aeria YCPUC79 Promotes Tomato Seedling Root Growth by Volatile Organic Compounds Emission(2024) Carvajal Contardo, Maria José; Albornoz Gutierrez, Francisco Javier; Catrileo, Daniela; Chorbadjian Alonso, Rodrigo Armen; Gebauer Hernández, Marlene Gloria; Godoy Olivares, LilianaBeneficial microorganisms promote plant growth through different mechanisms, such asthe production of plant hormones, the synthesis of 1-aminocyclopropane-1-carboxylic aciddeaminase (ACCD), or, through volatile organic compounds (VOCs) emission. There are numerousstudies describing a biostimulant action mediated by VOCs released by bacteria and filamentousfungi. However, in soil yeasts, research in this regard is still incipient. In a previous study, wepresent the stimulatory action of Solicoccozyma aeria YCPUC79 on tomato seedling growth byinoculating the rootzone with this yeast. The positive effect of S. aeria was related to the synthesis ofindole acetic acid (IAA) and the presence of ACCD activity by the yeast. In the present study, weevaluated whether S. aeria is capable of emitting VOCs with biostimulant activity. For this, anexperiment was conducted to test the release of VOCs in four treatments: S. aeria (Sa), tomatoseedlings (T), tomato seedlings sharing the ambient with S. aeria but with no physical contact (TSa)plus a control with no yeast nor tomato seedlings (C). Tomato seedlings exposed to S. aeria inoculum(TSa) presented 1.2-fold shorter main roots but increased the number of lateral roots by 80%compared to T. Regarding the analysis of VOCs, 59 compounds were identified excluding thosefound in the control treatment. These compounds represent twelve chemical families, includingalcohols, esters, furans, hydrocarbons, ketones and terpenes. The treatment TSa shows an increasedabundance of ketones, alcohols, esters, sulfur-containing compounds, and pyrazines in comparisonto T treatment. Three compounds (butyl hept-4-yl ester-phthalic acid, (E)1.3-pentadiene and 1-propenylthiol) were exclusively present in the TSa treatment. This study provides, for the first time,information on a soil yeast capable of promoting the production of lateral roots in tomato throughVOCs.
- ItemStep-Wise Ethanol Adaptation Drives Cell-Wall Remodeling and ROM2/KNR4 Activation in Brettanomyces bruxellensis(2025) Hernández-Cabello, Leslie; Rojas-Torres, Nachla; Godoy Olivares, Liliana; G-Poblete, Camila; Concha, Yarabi; Plaza, Verónica; Castillo, Luis; Mora-Montes, Héctor M.; Ganga, María AngélicaBrettanomyces bruxellensis has been described as the main spoilage microorganism in wines due to its ability to produce volatile phenols, which negatively impact the final product’s organoleptic properties. This yeast can grow and survive in environments that are too nutritionally poor and stressful for other microorganisms, and one of the stressful conditions it can endure is the high alcohol content in wine. In this study, cell wall morphology and the expression of some genes related to its composition were characterized under increasing ethanol concentrations to establish a possible ethanol resistance mechanism. B. bruxellensis LAMAP2480 showed greater resistance to β-1,3-glucanase activity when grown in media supplemented with 5% or 10% ethanol compared with the control assay (without ethanol). Transmission electron microscopy showed no significant differences in cell wall thickness during the different adaptation stages. However, the amount of wall polysaccharides and chitin briefly increased at 1% ethanol but returned to baseline at 5% and 10%. The amount of wall-associated protein increased progressively with each increment in ethanol concentration. In addition, overexpression of the ROM2 and KNR4/SMI1 genes was observed at 10% ethanol. These results suggest that the integrity of the cell wall might play an important role in the adaptation of B. bruxellensis to an ethanol-containing medium.
- ItemVolatile organic compounds produced after exposure of tomato roots to the soil yeast Solicoccozyma terrea modulate root nitrate transporters in tomato(2025) Albornoz Gutiérrez, Francisco Javier; Carvajal Contardo, Mariajose; Catrileo, Daniela; Gebauer Hernández, Marlene Gloria; Godoy Olivares, LilianaBackground Beneficial microorganisms modify root architecture through different mechanisms mostly related to plant hormones synthesis. Less information is available regarding the emission of microbial volatile organic compounds (VOCs) and their effects on root architecture. Numerous studies describe the release of VOCs by bacteria and filamentous fungi, but little information is available regarding soil yeasts.MethodsThe VOCs released by the soil yeast Solicoccozyma terrea were evaluated in an experiment with tomato seedlings. Four treatments (tomato seedlings, T; S. terrea inoculum without tomato seedlings, St; tomato seedlings exposed to the volatiles of S. terrea inoculum, TSt; and a control without tomato seedlings or yeast inoculum, C) were assessed in terms of root morphology. VOCs were analyzed by GC-MS, and in a second experiment, the response of tomato seedlings and root nitrate uptake transporters to specific compounds identified in the first experiment was evaluated under low and high N supply.ResultsA mixture with 57 VOCs was identified which promoted lateral roots formation in tomato plants. Three compounds (isopropyl alcohol, 2-pentylfuran and trans-1,3-pentadiene) were exclusively present in the TSt treatment. All three compounds stimulated lateral roots formation and increased root volume. These compounds showed a stimulatory effect on the expression of NRT1.2, NRT2.1 and NRT2.3 nitrate transporters under N deficiency conditions.ConclusionsThis study provides, for the first time, information on a soil yeast capable of promoting lateral roots formation in tomato through VOCs and that isopropyl alcohol, 2-pentylfuran and trans-1,3-pentadiene modulate root nitrate transporters expression under N deficiency conditions.