Characterization of selected species of Pichia and Candida for their growth capacity in apple and grape must and their biofilm parameters.

This article focuses on the characterization of biofilm-forming yeasts from the genera Pichia and Candida isolated from apples, grape musts, and wines, assessing their growth, fermentation capacity, and biofilm-related properties relevant to cider and wine production. The study analyzed 24 strains across 10 species, revealing that all strains grew similarly in apple and grape musts, but exhibited varied fermentation performance, sulfur dioxide (SO₂) and ethanol tolerance, and biofilm formation abilities, including distinct surface-spreading biofilm (MAT) phenotypes. Notably, strains of Pichia manshurica, P. membranifaciens, and P. kudriavzevii showed high tolerance to SO₂ and ethanol and strong biofilm-forming capacity, suggesting a greater potential to colonize fermentation tanks and negatively impact beverage quality. The findings highlight significant inter- and intraspecific variability in traits affecting fermentation and contamination risks, underscoring the importance of understanding these yeasts' biofilm properties for managing spoilage in alcoholic beverage production.