Summary

The current work examines the environmental conditions to control the expression of self-flocculation of Kloeckera apiculata mc1 isolated from Argentinian grapes with proven beneficial effect on wine aroma. Temperature had a direct effect on the expression of floc-culation resulting in an increase in the number of zymolectin sites determined with a BSA--Gal-FITC probe and quantified with the Scatchard plot. Agitation had a positive effect on yeast flocculation and the effect did not correlate with an increase in the hydrophobic in-dex. The addition of glucose, fructose or ethanol to yeast nitrogen base medium without amino acids or ammonium sulphate stimulated flocculation. Assimilative nitrogen sources had a negative impact on flocculation in the absence of an energy source. During wine-making, control of flocculation by environmental factors such as temperature and the pre-sence of nutrients could be applied in order to optimize the fermentation process and hence the quality of the final product. Knowledge of the effect of different parameters on floccu-lation of the wine yeast K. apiculata mc1 allows prediction of the behaviour of this yeast during fermentation. Key words: Kloeckera apiculata, wine yeast, flocculent phenotype, environmental condition