INVESTIGADORES
LOPES christian ariel
congresos y reuniones científicas
Título:
Saccharomyces in traditional fermentations from Patagonia
Autor/es:
RODRÍGUEZ M.E.; REBOZZIO R.; BARBAGELATA R.; SANGORRÍN M.; LOPES C.A.
Lugar:
Guadalajara
Reunión:
Simposio; 29th International Specialised Symposium on Yeast; 2011
Institución organizadora:
International Commission on Yeasts
Resumen:
Introduction. There is a lot of information about yeastdiversity in commercial fermentations (wine, cider);however, studies on traditional fermentations arescarce. No studies on traditional fermentations of pre-Columbian populations in Patagonia were reported.Some of the most relevant products include beveragesobtained from seeds (i.e. Mudai, obtained fromAraucaria araucana) or fruits (i.e. Chicha, made fromapples) of autochthonous or introduced plants [1].The aim of this work was to evaluate the yeastdiversity of two traditional fermentations fromPatagonia. Fermentative features of isolated yeastswere also analyzed.Methods. Yeasts were isolated from different stagesof alcoholic fermentations carried out at laboratoryscale mimicking traditional processes (Mudai andapple Chicha). Samples from Araucaria araucanatrees were samples following prodecure described byLopes et al. [2]. Yeast identification was carried out bymolecular (ITS-RFLP and D1/D2 26S sequences).Saccharomyces isolates were additionallycharacterized by mtDNA-RFLP and ITS-RFLP of 33nuclear genes [3]. New allele variants detected byPCR-RFLP were sequenced and compared withpublished data. Enological evaluation was carried outin micro-fermentations at 13°C on synthetic must.Wines obtained were evaluated in their physicalchemicalcharacteristics.Results and discussion.Yeasts from apple chichas. At the begining offermentation, the proportion of non-Saccharomycesyeasts varied between 25% and 84%, belonging toHanseniaspora uvarum and Metschnikowiapulcherrima species. Saccharomyces genuscompletely dominated middle and end stages. S.uvarum was the most frequent species end stages ofthree fermentations (92% in average), while S.cerevisiae dominated the final stages of twofermentations (80% in average). Fifteen differentmtDNA-RFLP patterns were detected among S.uvarum isolates and 6 among S. cerevisiae ones. Oneof the most frequently detected isolates of S.cerevisiae corresponded to a brewer yeast. Sequenceanalysis of nuclear genes obtained from S. cerevisiaeisolates evidenced that most alleles were common towine alleles present in Patagonian wine strainspreviously studied.Yeasts from Mudai and associated substrates.Yeast diversity in Mudai fermentation was very poor.Only Hanseniaspora uvarum and Saccharomycescerevisiae were detected. All S. cerevisiae isolatesshowed a same mtDNA-RFLP pattern correspondingto the same brewery commercial pattern from chichas.With the aim to find wild Saccharomyces strainsassociated with Mudai fermentations, samples fromAraucaria araucana seeds and barks from threeregions in Andean Northpatagonia were analyzed.After isolation, identification and characterization, atotal of 19 mtDNA-RFLP Saccharomyces patternswere found. PCR-RFLP pattens obtained for 33nuclear genes distributed along Saccharomyceschromosomes, allowed us to identify these isolates asbelonging to S. bayanus and S. uvarum species.Enological characterization. Yeast isolatesrepresentative of each S. bayanus and S. uvarummtDNA-RFLP pattern detected were evaluated in theirenologically relevant features in fermentations at13°C. In general, regional isolates produced a high erconcentration of glycerol and a lower concentration ofethanol than S. cerevisiae and they consumed thetotal quantity of glucose and fructose present in themedium.Conclusions. S. bayanus and S. uvarum isolatesfrom traditional fermentations and related substratesfrom Patagonia were detected for the first time. Theypossess interesting enological features to be considerfor wine fermentations at low temperature.Acknowledgements. This work was supported byGrant ANPCyT PICT-1449.References.1. Gómes, F.C.O., Lacerda, I.C.A., Libkind, D., Lopes, C. A.,Carvajal, J. and Rosa, C.A. (2010). Traditional foods andbeverages from South America: Microbial communities andproduction strategies. In: Industrial Fermentation: FoodProcesses, Nutrient Sources and Production Strategies(Eds. J. Krause and O. Fleischer) Chapter 3, 79-114. NovaScience Publishers, Inc.2. Sampaio, J.P., and Goncalves, P. (2008). Naturalpopulations of Saccharomyces kudriavzevii in Portugal areassociated with oak bark and sympatric with S. cerevisiaeand S. paradoxus. Appl. Environ. Microbiol. 74: 2144–2152.3. Lopes, C.; Barrio, E. and Querol A. (2010). Naturalhybrids of S. cerevisiae x S. kudriavzevii share alleles withEuropean wild populations of Saccharomyces kudriavzevii.FEMS Yeast Res.10: 412-421.