Abstract
Date seeds and cheese whey are mainly consisted or organic nitrogen sources, carbohydrates, lipids and minerals. These ingredients were utilized as natural medium for formation of citric acid by Candida lipolytica . Yield of citric acid was increased with the increase of fermentation period reaching its maximum at 96 hr. Yeast biomass was closely associated with citric acid formation. The best added carbon source was glucose which pushed the output of citric acid to high titres. The experimental organisms preferred utilizaton of inorganic nitrogen sources in the form of ammonia rather than nitrate nitrogen.