Cellar-associated Saccharomyces cerevisiae population structure revealed high diversity and perennial persistence in Sauternes wine estates
Résumé
Three wine estates were sampled in Sauternes, a typical appellation of Bordeaux wine area producing sweet white wine. Over those wine estates, 551 yeasts strains were collected between 2012 and 2014 adding 102 older strains from 1992 to 2011 from wine estate C. All strains were analyzed through 15 microsatellites markers resulting in 503 unique Saccharomyces cerevisiae genotypes, thus revealing a high genetic diversity, and a low presence of commercial yeast starters. Population analysis performed from Fst statistics, or from ancestry profiles, revealed that the two closest wine estates, B and C which have juxtaposed vineyard plots and common seasonal staff, share more related isolates together than with wine estate A indicating exchange between estates. The characterization of isolates collected 23 years ago in wine estate C related to recent isolates obtained in wine estate B revealed the long-term persistence of isolates. Last, during the 2014 harvest period, a temporal succession of ancestral subpopulations related to the different batches associated to the selective picking of noble rotted grapes was highlighted.
Importance A high genetic diversity of S. cerevisiae isolated from spontaneous fermentation in wine estates in the Sauternes appellation of Bordeaux were revealed. Only 7% of all Sauternes strains were considered as genetically related to specific commercial strains. The long-term persistence (over 20 years) of S. cerevisiae profils in a given wine estate was highlighted for the first time.