*2.1. Origin and Reactivation of theYeast S. cerevisiae*

The yeast used in this study has a commercial origin in fact, it is produced by the factory Lesaffre. The lyophilized form of *S. cerevisiae* was chosen due to several advantages, such as its availability, rapid growth, resistance to contaminants, easy cultivation, ability to consume most sugar and high yield production. The yeast was reactivated on agar plates containing YPGA medium composed of yeast extract 10 g/L, peptone 10 g/L, glucose 20 g/L, agar 20 g/L with a pH 6, incubated at 30 ◦C for 24 h. After development, the yeast was analyzed by macroscopic and microscopic characteristics in order to confirm its aspect.
