Dextrose

Candida albicans strain 1002 from Colección Española de Cultivos Tipo (CECT) were used in this study. Candida isolated was stored at −80 °C with 20% glycerol (Sigma-Aldrich, Saint Louis, MO, USA) until use. The strain was grown on Sabouraud chloramphenicol agar (Scharlab, Barcelona, Spain) overnight. To stimulate biofilm formation, various colonies were transferred into Yeast Extract (1%)–Peptone (2%)–Dextrose (2%) (YPD, Scharlab, Barcelona, Spain) and incubated at 37 °C with agitation (150 rpm) for 24 h.

Verdejo grapes were harvested from three different vineyards located in the AO Rueda during two vintages. Meteorological data are detailed in Figure S1. The work in the vineyards, belonging to Belondrade’s winery, located in the town of La Seca (Valladolid, Spain), was carried out according to ecological viticulture. Yeasts were isolated from spontaneously fermented musts in the Belondrade winery at different stages of the fermentation process (freshly crushed grape must, CM; racked must, RM; start of fermentation, SF; tumultuous fermentation, TF; end of fermentation, EF) on YPD agar containing 1% (w/v) yeast extract (Biolife, Milano, Italy), 2% (w/v) peptone (Panreac, Barcelona, Spain), 2% (w/v) dextrose (Scharlab, Barcelona, Spain), 2% (w/v) agar (Scharlab).

The culture medium consisted of 1% (w/v) yeast extract (Biolife), 2% (w/v) peptone (Panreac), 2% (w/v) dextrose (Scharlab), 0.2% (w/v) yeast β-glucan (Megazyme) and 2% (w/v) agar (Scharlab) [13 (link)]. A single colony was spread onto the plates and was incubated at 25 °C for 5–7 days. Afterwards, the colonies were rinsed with distilled water, and the surface of the plate was covered with 0.03% (w/v) Congo red solution (Sigma-Aldrich). Isolates with positive activity showed a clear halo on the surface, which the colonies covered with their growth.