Persistence and reservoirs of Saccharomyces cerevisiae biodiversity in different vineyard niches

Abstract

It is generally accepted that the vineyard is the natural habitat of wine yeasts and that specific native Saccharomyces cerevisiae strains can be associated with a terroir. However, some aspects remain unclear. The present study aimed to evaluate the persistence of S.cerevisiae in the vineyard ecosystem and to trace its niches. S. cerevisiae populations of different vineyard reservoirs were assessed along a complete grapevine growth cycle.Isolates were typed by interdelta-PCR, similarity´s coefficients and ecological diversity indices were estimated and dendrograms were performed by UPGMA. Eachstage of the cycle had a different diversity of S. cerevisiae strains. Ripen grapes showed the highest number and widest distribution across the vineyard. Soils showed low diversity suggesting their scarce contribution as reservoirs of these yeasts. Vine buds in winter and barks from sprouting to harvest showed to be good reservoirs. S. cerevisiae populations biodiversity analysis revealed a high differentiation between vineyard niches. Among environmental conditions, temperature was the main force driving S. cerevisiae population differentiation. A dynamic change of S.cerevisiae vineyard population was confirmed during the cycle. This work provides new insights in S. cerevisiae abundance in the vineyard environment, valuable to support its adaptation to the grapevine growth cycle.