RESUMO
AIMS: To study genomic and phenotypic changes in wine yeasts produced in short time periods analysing yeast strains possibly derived from commercial strains recently dispersed. METHODS AND RESULTS: We conducted a genomic and phenotypic comparison between the commercial yeast strain EC1118 and two novel strains (LV CB and L-957) isolated from different wine areas industrially intervened <20 years ago. Molecular analysis by amplified fragment length polymorphism (AFLP) and RAPD-PCR was not able to distinguish between these strains. However, comparative genomic hybridization (aCGH) showed discrete DNA gains and losses that allowed unequivocal identification of the strains. Furthermore, analysis of aCGH data supports the hypothesis that strains LV CB and L-957 are derivatives from strain EC1118. Finally, scarce phenotypic differences in physiological and metabolic parameters were found among the strains. CONCLUSION: The wine yeasts have a very dynamic genome that accumulates changes in short time periods. These changes permit the unique genomic identification of the strains. SIGNIFICANCE AND IMPACT OF THE STUDY: This study permits the evaluation of microevolutive events in wine yeasts and its relationship with the phenotype in this species.
Assuntos
Variação Genética , Genoma Fúngico , Fenótipo , Saccharomyces cerevisiae/fisiologia , Vinho/microbiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Hibridização Genômica Comparativa , Dosagem de Genes , Técnica de Amplificação ao Acaso de DNA Polimórfico , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/isolamento & purificação , Proteínas de Saccharomyces cerevisiae/genéticaRESUMO
AIMS: The purpose of this study was to identify yeast species present in spoiled and unspoiled grape juice concentrates from Argentine industries. METHODS AND RESULTS: Osmophilic and osmotolerant yeasts were isolated from spoiled--visually effervescent--and unspoiled--without any visible damage--grape juice concentrates by the spread-plate technique in two culture media. Yeast identification was done by classical and molecular methods. Zygosaccharomyces rouxii was the only species isolated from spoiled grape juice concentrates. In unspoiled samples, five different species were identified: Z. rouxii was isolated at a higher frequency, followed in decreasing order by Saccharomyces cerevisiae, Schizosaccharomyces pombe, Pichia anomala and Kluyveromyces delphensis. CONCLUSIONS: Yeasts isolated from grape juice concentrates were characterized by a limited taxonomic diversity, where Z. rouxii was the main species isolated. SIGNIFICANCE AND IMPACT OF THE STUDY: Grape production in Argentina is mainly devoted to the industry where wine and grape juice concentrates represent major types of commercial products. Little information on common yeast contaminants is available for grape juice concentrates. This study constitutes the first report of osmophilic yeast species present in spoiled and unspoiled grape juice concentrates elaborated in Argentina.