Optimization of Culture Medium for Bakerʹs Yeast, Ethanol, Citric Acid and A-amylase Production from Dates Syrup.

The aim of this study is to optimize the production of Bakerʹs yeast, Citric acid, Ethanol and a-amylase using dates of low market value as the basal fermentation medium. The results of this study showed that the optimal Bakerʹs yeast production was obtained with a dilution rate of 0.22 h-1. Also, the use of ammonium phosphate provides better biomass yields compared to urea. As for the Ethanol production, the optimum yield obtained was 131.0 g/L under optimum conditions of an incubation period of 72 h, inoculums content of 4 % (w/v), sugars concentration of 180.0 g/L and ammonium phosphate concentration of 1.0 g/L. Concerning the Citric acid production, the cumulative effect of temperature (30 °C), methanol concentration (3%), initial pH (3.5) and ammonium nitrate concentration (2.5 g/L) during the fermentation process of dates syrup did increase the citric acid production to 97.0 g/L. Finally, the maximum a-amylase activity obtained was 2600 ^mol/L/min under optimum conditions of an incubation period of 96 h, temperature of 30 °C, an initial pH of 5.5, sugars concentration of 20 g/L, yeast extract concentration of 5.0 g/L and phosphorus concentration of 5.0 g/L.