As a primary study for SCP production from soybean curd waste water, selection of yeast and optimum cultivation condition of selected yeast on soybean curd waste water were investigated.
Eighteen strains of the genus Candida and Saccharamyces were tested to compare their abilities to grow on soybean curd waste water. Candida utilis YUFE 1508 and Candida guilliermondii KFCC 35120 grew most successfully. Optimum pH and optimum temperature of the basal medium for growth of the two strains were 6.0∼6.5 and 25℃, respectively.
The optimum culture medium of the two yeasts was soybean curd waste water supplemented with molasses 2.5% (as total sugar), ammonium acetate 0.1-0.3% (as nitrogen), KH₂ PO₄ 0.1-0.2% (as phosphorus), and KH₂ PO₄ 0.05% (as Phosphorus). But yeast growth was not affected by metal salts.
Under the optimum cultivation condition, the maximum cell weights of Candida utilis YUFE 1508 and Candida guillfermondii KFCC 55120 were 1.3138 and 1.322g/100㎖ of culture broth respectiyely after 4g hr of cultivation. The cell yields of Candida utilis YUFE 1508 and Candida guilliermondii KFCC 35120 were 68.4% and 74.2%, respectively, based on utilized sugar. On the other hand, crude protein of dry yeast produced by Candida utilis YUFE 1508 and Candida guilliermondii KFCC 35120 under optimum condition was 54.0% and 56.8%, respectively.
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