Identificación morfológica y molecular de aislamientos del agente etiológico del oídio del zapallo (Cucurbita moschata) en la provincia de San Juan

El oídio del zapallo es una importante enfermedad fúngica foliar que afecta cultivos crecidos a campo e invernadero (Miazzi et al., 2011). Se caracteriza por que aparece sobre las hojas como puntos blancos pulverulentos, y puede cubrir por completo ambas superficies foliares y extenderse sobre peciolos y tallos. Como consecuencia de la infección, se produce una defoliación prematura, afectando el rendimiento y calidad de los frutos y, en casos severos, la muerte temprana de la planta (McGrath et al., 1996). Esta enfermedad se atribuye mayoritariamente a dos hongos biótrofos pertenecientes al orden Erysiphales (Ascomicota): Podosphaera xanthii y Golovinomyces cichoracearum. En nuestro país, y particularmente en San Juan, existe escasa información sobre la etiología de la enfermedad. Por consiguiente, el objetivo de este trabajo fue aislar e identificar morfológica y genéticamente al agente causal del oídio en un cultivo de C. moschata en la provincia de San Juan.Fil: Soria, Florencia Elizabeth. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; ArgentinaFil: Nally, María Cristina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Paz, Rosalía Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina40°Congreso Argentino de HorticulturaCórdobaArgentinaAsociación Argentina de Horticultur

Bioprospecting of the probiotic potential of yeasts isolated from a wine environment

Autochthonous yeasts of oenological origin are adapted to highly stressful and selective environments, which makes them potential candidates for probiotics. The objective of the present study was to explore the probiotic potential of 96 native yeasts of oenological origin, their biosafety, resistance to gastrointestinal tract conditions and adhesion properties. Regarding biosafety, 66 isolates shown negative hemolytic activity, negative urease activity and susceptibility to 3 or more antifungals. After the gastrointestinal resistance test, 15 isolates were selected that showed growth at different temperatures, tolerance to low pH and the presence of bile salts in in vitro tests. In general, survival after simulated conditions of the gastrointestinal tract was high and more restrictive was the duodenal. The results of the adhesion properties showed highly variable hydrophobicity and a high percentage of autoaggregation at 24 h. The maximum production of biofilm was detected in the Pichia strains. Of a total of 96 yeast strains, 15 non-Saccharomyces yeasts presented suitable properties as probiotic candidates. The native winemaking strains performed better than the reference probiotic strain, Saccharomyces cerevisiae var. boulardii CNCM I-745, which reaffirms that these strains are promising probiotic candidates and further studies are necessary to confirm their probiosis.Fil: Vergara Alvarez, Silvia Cristina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Leiva Alaniz, María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Mestre Furlani, María Victoria. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Mancha Agresti, Pamela. Centro Federal de Educação Tecnológica; BrasilFil: Cristina Nally, María. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentin

Monitoring of killer yeast populations in mixed cultures: influence of incubation temperature of microvinifications samples

Killer yeasts are frequently used to combat and prevent contamination by wild-type yeasts during wine production and they can even dominate the wine fermentation. Stuck and sluggish fermentations can be caused by an unbalanced ratio of killer to sensitive yeasts in the bioreactor, and therefore it is important to determine the proportion of both populations. The aim of this study was to provide a simple tool to monitor killer yeast populations during controlled mixed microvinifications of killer and sensitive Saccharomyces cerevisiae. Samples were periodically extracted during vinification, seeded on Petri dishes and incubated at 25 and 37 °C; the latter temperature was assayed for possible inactivation of killer toxin production. Colonies developed under the described conditions were randomly transferred to killer phenotype detection medium. Significant differences in the killer/sensitive ratio were observed between both incubation temperatures in all microvinifications. These results suggest that 37 °C seems a better option to determine the biomass of sensitive yeasts, in order to avoid underestimation of sensitive cells in the presence of killer yeasts during fermentations. Incubation at a toxin-inhibiting temperature clearly showed the real ratio of killer to sensitive cells in fermentation systems.Fil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Nally, María Cristina. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Toro, María Eugenia. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Castellanos de Figueroa, Lucía Inés. PROIMI; Argentina. Universidad Nacional de Tucumán. FBQyF; ArgentinaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentin

Free Volatile Compounds of cv. Pedro Giménez (Vitis vinifera L.) White Grape Must Grown in San Juan, Argentina

The free aromatic composition of must from Pedro Giménez grapes, grown in San Juan, Argentina, was characterised. Samples from the vintages of 2008 and 2009 were analysed by gas chromatography–mass spectrometry–solid phase microextraction (GC–MS–SPME). Higher alcohols, terpenes, C13-norisoprenoids, esters, aldehydes and ketones were quantified. The calculation of the odour activity values (OAVs) revealed that β-damascenone, α-ionone, β-linalool, geraniol, ethyl butanoate, hexanoate and octanoate were the most prevalent aroma-active compounds of the grape variety. However, the remaining 42 aromatic compounds that registered OAVs less than 1 could potentially contribute to the flavour of Pedro Giménez grapes. The measured monoterpene levels indicate that the Pedro Giménez grape can be considered a neutral variety. This is the first report describing the main potential free aroma contributors of Pedro Giménez grapes in two consecutive years.EEA MendozaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nally, María Cristina. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Assof, Mariela Vanesa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; ArgentinaFil: Toro, María Eugenia. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Castellanos de Figueroa, Lucía Inés. PROIMI; Argentina. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jofre, Viviana Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentin

Microbial Biopesticides: Diversity, Scope, and Mechanisms Involved in Plant Disease Control

Food losses, defined as a reduction in the quantity and quality of food during production and storage, impact food safety and security. Losses caused by plant pathogens are among the most significant. Chemical pesticides have been extensively used to prevent microbial diseases. Their toxicity and reduced efficacy, however, have encouraged investigators to develop alternatives. Alternatives based on microbial biopesticides tend to be safer and more environmentally benign than conventional pesticides. In recent years, formulations based on biopesticides have progressively increased in number and diversity and have attracted commercial interest. Understanding the mechanisms by which biopesticides control the disease is fundamental to achieving optimal disease control. Biocontrol mechanisms can be divided into two main categories: those related to the ability to inhibit pathogens or their virulence factors, and those that enhance host plant fitness and induce disease resistance. Here, the first type of strategy is reviewed, which is directly mediated by physical contact between biocontrol agents and pathogens or indirectly by exposure of a pathogen to antimicrobial or microbial-inhibiting compounds produced by the microbial antagonist. Mechanisms involving physical contact include mycophagy, destruction of pathogenic bacteria by bacteriophages or predation, and disease inhibition by topical applications of specific dsRNA. Indirect mechanisms that do not involve direct contact with a pathogen include the production of antimicrobial compounds, competition, and virulence factor suppression by quorum quenching. These topics are reviewed and discussed.Fil: Vero, Silvana. Universidad de la República. Facultad de Química. Área de Microbiología;Fil: Garmendia, Gabriela. Universidad de la República. Facultad de Química. Área de Microbiología;Fil: Allori Stazzonelli, Enzo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucuman. Facultad de Agronomia y Zootecnia. Departamento de Ecología; ArgentinaFil: Sanz, José María. Fundación CARTIF; EspañaFil: Gonda, Mariana. Universidad de la República. Facultad de Química. Área de Microbiología;Fil: Alconada Magliano, Teresa Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Cavello, Ivana Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Diaz, Mariana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Nally, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Pimenta, Raphael Sanzio. Universidade Federal do Tocantins; BrasilFil: Fonseca Moreira da Silva, Juliana. Universidade Federal do Tocantins; BrasilFil: Vargas, Marisol. Universidad de Concepción; ChileFil: Zaccari, Fernanda. Universidad de la República; UruguayFil: Wisniewski, Michael. Virginia Polytechnic Institute; Estados Unidos. Virginia State University; Estados Unido

Microbial biopesticides: diversity, scope, and mechanisms involved in plant disease control

Food losses, defined as a reduction in the quantity and quality of food during production and storage, impact food safety and security. Losses caused by plant pathogens are among the most significant. Chemical pesticides have been extensively used to prevent microbial diseases. Their toxicity and reduced efficacy, however, have encouraged investigators to develop alternatives. Alternatives based on microbial biopesticides tend to be safer and more environmentally benign than conventional pesticides. In recent years, formulations based on biopesticides have progressively increased in number and diversity and have attracted commercial interest. Understanding the mechanisms by which biopesticides control the disease is fundamental to achieving optimal disease control. Biocontrol mechanisms can be divided into two main categories: those related to the ability to inhibit pathogens or their virulence factors, and those that enhance host plant fitness and induce disease resistance. Here, the first type of strategy is reviewed, which is directly mediated by physical contact between biocontrol agents and pathogens or indirectly by exposure of a pathogen to antimicrobial or microbial-inhibiting compounds produced by the microbial antagonist. Mechanisms involving physical contact include mycophagy, destruction of pathogenic bacteria by bacteriophages or predation, and disease inhibition by topical applications of specific dsRNA. Indirect mechanisms that do not involve direct contact with a pathogen include the production of antimicrobial compounds, competition, and virulence factor suppression by quorum quenching. These topics are reviewed and discussed.Centro de Investigación y Desarrollo en Fermentaciones Industriale

Levaduras vitivinícolas reductoras de la concentración de aflatoxinas en pistachos

El pistacho (Pistacia vera) es un fruto seco que se encuentra en expansión y con una creciente demanda a nivel internacional. La provincia de San Juan se presenta como la principal productora y en los últimos tres años exportó 379,32 tn de pistachos. Los pistachos son susceptibles a la contaminación de hongos del género Aspergillus que representan una amenaza para la calidad y el mercado internacional de los pistachos argentinos. Aspergillus flavus es el principal productor de aflatoxinas en pistacho. La aflatoxina B1 es considerada la más toxica y su concentración está regulada a nivel mundial. Existen diferentes métodos de reducción de aflatoxinas (físicos, químicos y biológicos). Diferentes microorganismos son capaces de reducir la producción de aflatoxinas, tales como cepas atoxicogénicas de A. flavus, bacterias y levaduras. El presente trabajo evaluó la capacidad de reducción de aflatoxinas de levaduras pertenecientes a las especies Metschnikowia pulcherrima (Mp36) y Saccharomyces cerevisiae (PB66, PB69, PB70, PB74) aisladas de mostos en fermentación frente a A. flavus (H5) aislado de pistacho. Placas de petri con 42 g de pistacho fueron inoculadas con 10 mL de una suspensión de levaduras (1x108 UFC/mL). Posteriormente se colocó en el centro de la placa un disco de micelio proveniente de un cultivo activo del patógeno. El control consistió en pistacho inoculado sólo con el patógeno. Las placas se incubaron a 25 °C durante 5 días. Luego de la incubación los pistachos fueron molidos y la concentración de aflatoxinas de las muestras se cuantificó mediante HPLC. Las levaduras redujeron la concentración de aflatoxinas entre el 0% y el 97%.  La levadura S. cerevisiae PB74 produjo una mayor reducción de aflatoxinas frente a A. flavus H5 con un porcentaje del 97%. Por otra parte, las levaduras S. cerevisiae PB69 y PB70 presentaron porcentajes de reducción del 95% y 90% respectivamente. La levadura M. pulcherrima Mp36 presentó un porcentaje de reducción del 53%. La levadura S. cerevisiae PB66 (0%) no redujo la producción de aflatoxinas. Además, se comprobó que el patógeno A. flavus H5 en el tratamiento control produjo mayor concentración de aflatoxina B1 (664,2 µg/kg) mientras que produjo valores muy bajos de las aflatoxinas B2 (2,7 µg/kg), G1 (0 µg/kg) y G2 (3,3 µg/kg). Esta reducción podría estar relacionada con los diferentes mecanismos de competencia de interacciones entre las levaduras biocontroladoras y el patógeno. Basado en las capacidades de las levaduras para reducir la producción de aflatoxinas de A flavus (H5) del presente estudio se considera que son excelentes candidatas para futuros ensayos.Facultad de Ciencias Agrarias y Forestale

Biocontrol of Botrytis cinerea in table grapes by non-pathogenic indigenous Saccharomyces cerevisiae yeasts isolated from viticultural environments in Argentina

Botrytis cinerea, the causal agent of gray mold, is an important disease of grapes. Yeasts are members of the epiphytic microbial community on surfaces of fruits and vegetables and because some yeasts inhibit fungi they are used as biocontrol agents. The major objective of the present work was to isolate yeasts from grapes, vineyard soil, and grape must and select them for their ability to prevent gray mold onset after harvest. Yeasts that were found effective against the fungus were also assayed for their possible pathogenicity in humans. Two antagonism experiments were performed to study the effect of yeasts on B. cinerea, an in vitro study with Czapeck Yeast Extract Agar and an in vivo study with grape berries at 2 °C and 25 °C; both experiments were conducted at different yeast concentrations (105, 106 and 107 cfu/mL). Antagonists were subsequently assayed for their ability to colonize and grow in fruit wounds. The biocontrol yeasts were also examined for their possible pathogenicity in humans: phospholipase and proteolytic activity, growth at 37 °C and 42 °C, pseudohyphal formation and invasive growth. A total of 225 yeasts belonging to 41 species were isolated from must and grape berries and 65 of them, representing 15 species, exhibited in vitro inhibition of B. cinerea at 25 °C. These 65 biocontrol yeasts were subsequently assayed in vivo and 16 of them (15 Saccharomyces cerevisiae and 1 Schizosaccharomyces pombe) showed antagonistic properties against B. cinerea at 25 °C. Only one isolate (S. cerevisiae BSc68) was able to inhibit mycelial growth of B. cinerea on grape berries at both 2 °C and 25 °C. The biomass of this strain in grape wounds increased 221.5-fold at 25 °C after 3 d and 325.5-fold at 2 °C after 10 d of incubation. An increase in the concentration of certain yeasts significantly enhanced their antagonistic activity. All yeast isolates determined as biocontrol agents under in vivo conditions were isolated from fermenting musts. Twelve biocontrol agents (S. cerevisiae) revealed one or more phenotypical characteristics associated with pathogenicity in humans but none of them showed all characteristics together. The fact that there exist few reports on S. cerevisiae and none on Sch. pombe as biocontrol agents against B. cinerea makes our results even more relevant.EEA MendozaFil: Nally, María Cristina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Pesce, Virginia Mercedes. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Muñoz, Claudio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Combina, Mariana. Estación Experimental Agropecuaria Mendoza. Centro de Estudios Enológicos; ArgentinaFil: Toro, María Eugenia. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Castellanos de Figueroa, Lucía Inés. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentin

Multi-enzyme production by pure and mixed cultures of Saccharomyces and non-Saccharomyces yeasts during wine fermentation

Saccharomyces and non-Saccharomyces yeasts release enzymes that are able to transform neutral compounds of grape berries into active aromatic compounds, a process that enhances the sensory attributes of wines. So far, there exists only little information about enzymatic activity in mixed cultures of Saccharomyces and non-Saccharomyces during grape must fermentations. The aim of the present work was to determine the ability of yeasts to produce extracellular enzymes of enological relevance (β-glucosidases, pectinases, proteases, amylases or xylanases) in pure and mixed Saccharomyces/non-Saccharomyces cultures during fermentation. Pure and mixed cultures of Saccharomyces cerevisiae BSc562, Hanseniaspora vinae BHv438 and Torulaspora delbrueckii BTd259 were assayed: 1% S. cerevisiae/99% H. vinae, 10% S. cerevisiae/90% H. vinae, 1% S. cerevisiae/99% T. delbrueckii and 10% S. cerevisiae/90% T. delbrueckii. Microvinifications were carried out with fresh must without pressing from Vitis vinifera L. c.v. Pedro Jiménez, an autochthonous variety from Argentina. Non-Saccharomyces species survived during 15–18 days (BTd259) or until the end of the fermentation (BHv438) and influenced enzymatic profiles of mixed cultures. The results suggest that high concentrations of sugars did not affect enzymatic activity. β-Glucosidase and pectinase activities seemed to be adversely affected by an increase in ethanol: activity diminished with increasing fermentation time. Throughout the fermentation, Saccharomyces and non-Saccharomyces isolates assayed produced a broad range of enzymes of enological interest that catalyze hydrolysis of polymers present in grape juice. Vinifications carried out by a pure or mixed culture of BTd259 (99% of T. delbrueckii) showed the highest production of all enzymes assayed except for β-glucosidase. In mixed cultures, S. cerevisiae outgrew H. vinae, and T. delbrueckii was only detected until halfway the fermentation process. Nevertheless, their secreted enzymes could be detected throughout the fermentation process. Our results may contribute to a better understanding of the microbial interactions and the influence of some enzymes on vinification environments.EEA MendozaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Rodriguez Assaf, Leticia Anahi. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Toro, María Eugenia. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Nally, María Cristina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Vallejo, Martha Dina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Castellanos de Figueroa, Lucía Inés. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Centro de Estudios Enológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentin

Yeast population dynamics during prefermentative cold soak of Cabernet Sauvignon and Malbec wines

Prefermentative cold soak is a widely used technique in red wine production, but the impact on the development of native yeast species is hardly described. The aim of this work was to analyse the dynamics and diversity of yeast populations during prefermentative cold soak in red wines. Three different temperatures (14 ± 1 °C; 8 ± 1 °C and 2.5 ± 1 °C) were used for prefermentative cold soak in Cabernet Sauvignon and Malbec grape musts. Saccharomyces and non-Saccharomyces populations during cold soak and alcoholic fermentation were analysed. In addition, the impact on chemical and sensory properties of the wines was examined. Yeast dynamics during prefermentative cold soak were temperature dependent. At 14 ± 1 °C, the total yeast population progressively increased throughout the cold soak period. Conversely, at 2.5 ± 1 °C, the yeast populations maintained stable during the same period. Prefermentative cold soak conducted at 14 ± 1 °C favoured development of Hanseniospora uvarum and Candida zemplinina, whereas cold soak conducted at 8 ± 1 °C favoured growth of Saccharomyces cerevisiae. At 2.5 ± 1 °C, no changes in yeast species were recorded. Acidity and bitterness, two sensory descriptors, appear to be related to wines produced with prefermentative cold soak carried out at 14 ± 1 °C. This fact could be associated with the increase in non-Saccharomyces during the prefermentation stage. Our results emphasise the importance of the temperature as a determinant factor to allow an increase in non-Saccharomyces population during prefermentative cold soak and consequently to modify sensorial attributes of wines as well as their sensorial impact.EEA MendozaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mestre Furlani, Maria Victoria. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Esteve Zarzoso, Braulio. Universitat Rovira i Virgili. Facultat d’ Enologia. Departament de Bioquímica i Biotecnologia, Biotecnologia Enològica; EspañaFil: Nally, María Cristina. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lerena, María Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Toro, María Eugenia. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin