Patagonian wines: the selection of an indigenous yeast starter

Abstract

The use of selected yeasts for winemaking has clear advantages over the traditional spontaneous fermentation. The aim of this study was to select an indigenous Saccharomyces cerevisiae yeast isolate in order to develop a regional North Patagonian red wine starter culture. A two-step selection protocol developed according to physiological, technological and ecological criteria based on killer interactions was used. Following this methodology, S. cerevisiae isolate MMf9 was selected among 32 indigenous yeasts previously characterized as belonging to different strains according to molecular patterns and killer biotype. This isolate showed interesting technological and qualitative features including high fermentative power and low volatile acidity production, low foam and low sulphide production, as well as relevant ecological characteristics such as resistance to all indigenous and commercial S. cerevisiae killer strains assayed. Red wines with differential volatile profiles and interesting enological features were obtained at laboratory scale by using this selected indigenous strain.

Characterization of some indigenousSaccharomyces cerevisiaeisolates obtained during vinification of ‘Kalecik Karasi’ and ‘EMIR’ grapes grown in Central Anatolia

“…Table III H2S production by indigenous S. cerevisiae isolates In a study performed for the selection of indigenous S. cerevisiae isolates suitable for wine production, H 2 S production of 32 S. cerevisiae isolates were tested and it was reported that all of the tested isolates produced H 2 S (Lopes et al, 2007). Also, Spiczki et al (2001) reported that all of the tested S. cerevisiae, S. paradoxus and S. bayanus strains were found to produce H 2 S at the level of 5 and it is recommended the strains to be genetically modified before using as starter culture for wine fermentation.…”

“…In another study, ethanol tolerance of wine yeasts was investigated and 106 of 632 yeast strains were found to grow at 10% (v/v) ethanol concentration (Benítez et al, 1983). Lopes et al (2007) reported that 32 indigenous S. cerevisiae strains were able to begin fermentation at 5 and 10% (v/v) ethanol concentration. Besides, it was reported that only three of the tested S. cerevisiae strains were able to ferment at 15% (v/v) ethanol concentration.…”

“…Today, the use of indigenous wine yeasts selected from each wine production region is widespread (Lopes et al, 2007). These indigenous yeasts are presumed to be more competitive than commercial yeasts because they are better adapted to the ecological and technological conditions of their own region.…”

“…Therefore, they have potential of dominating the fermentation and might become the most important biological agent responsible for the winemaking. Additionally, selection of the appropriate local yeasts would assure the production of quality premium wines maintaining the differential properties of their own region and preserving its natural biodiversity (Lopes et al, 2007). Criteria for the selection and development of yeasts for wine fermentation have evolved over many years and were discussed by Regodon et al (1997), Rainieri and Pretorius (2000), Schuller and Casal (2005) and Suarez- Lepe and Morata (2012).…”

Caracterización de un cepario de levaduras para uso enológico mediante técnicas moleculares

“…Las especies de levaduras que intervienen en la fermentación del mosto de la uva, en particular la más extendida de ellas, S. cerevisiae, incluye un gran número de cepas cuyas propiedades tecnológicas son extremadamente variables [2][3][4]). Poder diferenciar a un nivel intraespecífico (cepas) las levaduras S. cerevisiae resulta fundamental en diversos aspectos de la microbiología enológica.…”