Flocculation and Expression of FLO Genes of a Saccharomyces cerevisiae Mezcal Strain with High Stress Tolerance.

Autor: Vergara-Álvarez I; National Polytechnic Institute (Instituto Politécnico Nacional), Center for Genomic Biotechnology, Blvd del Maestro s/n esq, Elías Piña Col. Narciso Mendoza, C.P. 88710, Reynosa (Tamaulipas), Mexico.; Aix-Marseille University, LCB (UMR7283), CNRS, Marseille, France., Quiroz-Figueroa F; National Polytechnic Institute (Instituto Politécnico Nacional), CIIDIR-IPN Unidad Sinaloa, Blvd. Juan de Dios Bátiz Paredes no. 250, Col. San Joachin, C.P. 81101 Guasave (Sinaloa), Mexico., Tamayo-Ordóñez MC; National Polytechnic Institute (Instituto Politécnico Nacional), Center for Genomic Biotechnology, Blvd del Maestro s/n esq, Elías Piña Col. Narciso Mendoza, C.P. 88710, Reynosa (Tamaulipas), Mexico.; Genetic Engineering Laboratory, Department of Biotechnology, Faculty of Chemical Sciences, Autonomous University of Coahuila, Saltillo Unit, Mexico., Oliva-Hernández AA; National Polytechnic Institute (Instituto Politécnico Nacional), Center for Genomic Biotechnology, Blvd del Maestro s/n esq, Elías Piña Col. Narciso Mendoza, C.P. 88710, Reynosa (Tamaulipas), Mexico., Larralde-Corona CP; National Polytechnic Institute (Instituto Politécnico Nacional), Center for Genomic Biotechnology, Blvd del Maestro s/n esq, Elías Piña Col. Narciso Mendoza, C.P. 88710, Reynosa (Tamaulipas), Mexico., Narváez-Zapata JA; National Polytechnic Institute (Instituto Politécnico Nacional), Center for Genomic Biotechnology, Blvd del Maestro s/n esq, Elías Piña Col. Narciso Mendoza, C.P. 88710, Reynosa (Tamaulipas), Mexico.
Jazyk: angličtina
Zdroj: Food technology and biotechnology [Food Technol Biotechnol] 2019 Dec; Vol. 57 (4), pp. 544-553.
DOI: 10.17113/ftb.57.04.19.6063
Abstrakt: Mezcal is a distillate produced by spontaneous fermentation of the must obtained from stalks of Agave spp. plants that are cooked and pressed. Agave must contains a high amount of fructose and phenolic compounds, and fermentation usually occurs under stressful (and uncontrolled) environmental conditions. Yeasts capable of growing under such conditions usually display advantageous biological and industrial traits for stress tolerance such as flocculation. In this study, seven Saccharomyces cerevisiae strains isolated from mezcal must were exposed to temperatures ranging between 10 and 40 °C, and to different sugar sources (fructose or glucose). Yeasts grown in fructose increased their stress tolerance, determined by colony count in a microdrop assay, under low temperature (10 °C) compared to the growth at 40 °C on solid cultures. The most stress-tolerant mezcal strain (Sc3Y8) and a commercial wine (Fermichamp) strain, used as control, were grown under fermentation conditions and exposed to long-term temperature stress to determine their performance and their potential for flocculation. Compared to glucose, fermentation on fructose increased the metabolite accumulation at the end of culture, particularly at 40 °C, with 2.3, 1.3 and 3.4 times more glycerol (8.6 g/L), ethanol (43.6 g/L) and acetic acid (7.3 g/L), respectively. Using confocal microscopy analysis, we detected morphological changes such as aggregation and wall recognition at the level of budding scars in yeast, particularly in the Sc3Y8 strain when it was exposed to 40 °C. The analysis confirmed that this mezcal strain was positive for flocculation in the presence of Ca 2+ ions. Analysis of FLO1 , FLO5 and FLO11 gene expression implicated in flocculation in both Saccharomyces strains showed a strong transcriptional induction, mainly of the FLO5 gene in the mezcal Sc3Y8 strain.
Competing Interests: CONFLICT OF INTEREST: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Databáze: MEDLINE
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