Isolation of a flocculating Saccharomyces cerevisiae and investigation of its performance in the fermentation of beet molasses to ethanol

The present study aims at evaluating the performance of the relative importance of different types of interactions in yeast cell flocculation. The yeasts isolated from several sources, purified and identified by morphological and biochemical methods. About 50 strains of yeast were isolated on PDA medium, among those strains six strains were flocculent and one of them was identified as Saccharomyces cerevisiae. The influence of different additives on the flocculation was investigated and it was shown that pistacia gum (turpentine) increases the flocculation up to 93.8%. Addition of ammonium sulfate (0.2 g l−1) increases the production of alcohol to 6.19%.