Variable flocculation profiles of yeast strains isolated from cachaça distilleries

• Flocculation was evaluated on strains isolated from cachaça distilleries.
• Phenotypic flocculation was independent from bottom/top-fermenting behavior.
• Cell wall parameters were not associated with strength and phenotype flocculation.
• Expression of FLO genes explain the fermenting behavior of some cachaça strains.

In cachaça production, the use of yeast cells as starters with predictable flocculation behavior facilitates the cell recovery at the end of each fermentation cycle. Therefore, the aim of this work was to explain the behavior of cachaça yeast strains in fermentation vats containing sugarcane through the determination of biochemical and molecular parameters associated with flocculation phenotypes. By analyzing thirteen cachaça yeast strains isolated from different distilleries, our results demonstrated that neither classic biochemical measurements (e.g., percentage of flocculation, EDTA sensitivity, cell surface hydrophobicity, and sugar residues on the cell wall) nor modern molecular approaches, such as polymerase chain reaction (PCR) and real-time PCR (q-PCR), were sufficient to distinctly classify the cachaça yeast strains according to their flocculation behavior. It seems that flocculation is indeed a strain-specific phenomenon that is difficult to explain and/or categorize by the available methodologies.