UTILIZATION OF SAUDI DATE SUGARS IN PRODUCTION OF BAKERS-YEAST

Six different yeasts: Saccharomyces cerevisiae (I); S. dastorianus NRR L Y-12693; S. cerevisiae (II); S. dayanus NRRL Y-12624; S. cerevisiae NRRL Y-12632 and S. lodgwii were cultivated in different fermentation media. The results showed that S. cerevisiae (I) gave the highest biom ass production. Sefry Beesha dates contained 60% total reducing sugars . When blackstrap molasses, the carbon source of the fermentation medi um, was replaced by an equivalent amount of Sefry Beesha date sugars, they were as suitable as the molasses in the production of yeast. The best date-sugar concentration was 50.0 mg/ml. Ammonium sulphate was a good nitrogen source, at a concentration of 2.0 mg/ml, for the product ion of yeast biomass. Biotin, at a concentration of 50 mu g/l, was a g ood growth stimulator for S. cerevisiae (I). The ash of S. cerevisiae (I) contained Na, Mg, Ca, Fe, Zn and Cu. Cobalt and Ni were not detect ed. The concentrations of these metals in the baker's yeast are non-to xic.