Abstract
Worldwide, S. cerevisiae var. boulardii is the only commercial yeast with a probiotic character used to make fermented beverages. For this reason, there is a need to identify new strains with potential probiotic characteristics. The objective of this work was to isolate, phenotypically characterize, and determine the potential probiotic character of yeasts from native honeys produced in Chile: Ulmo (Eucryphia cordifolia), Quillay (Quillaja saponaria), and mountain honeys. Yeasts were isolated by plating in selective media, and morphologically characterized into four groups. Six yeast strains were identified: Zygosaccharomyces rouxii, Candida sp., Schizosaccharomyces pombe, Rhodosporidiobolus ruineniae, Clavispora lusitaniae, and Metschnikowia chrysoperlae. The phenotypic characterization of the isolated strains was carried out at different concentrations of glucose and fructose. In addition, resistance tests to ethanol (5°- 8°), pH (3.5), hops (50IBU - 90IBU), high temperatures (37°C), and self-aggregation capacity were performed. It was found that the yeasts with the best resistance to the different treatments were R. ruineniae and Cl. lusitaniae, reaching their exponential phase after 24 hours of fermentation (about 9 log CFU/mL), while the other isolates survived but with lower yields. The self-aggregation capacity of the six yeasts was about 80% -100%. Our results suggests that the isolates are able to metabolize sugars, and resist stress conditions associated to alcoholic beverages production. In addition, the self-association assay showed a characteristic connected commonly to probiotic microorganisms, however their survival after digestion still needs to be studied.
Presenters
Adrian Rodríguez MahadoStudent, Ingeniero Químico, Pontificia Universidad Católica de Chile, Región Metropolitana de Santiago, Chile
Details
Presentation Type
Theme
KEYWORDS
Probiotic Yeast, Functional Alcoholic Beverages, Unconventional Yeast
