FROM POTENTIAL TO REALITY - YEASTS DERIVED FROM ETHANOL-PRODUCTION FOR ANIMAL NUTRITION

The high costs of cereals and vegetable protein supplements used for a nimal nutrition have directed much attention toward non-conventional a lternative protein sources. Brazil has a significant potential to prov ide such material, since it is the world's largest producer of ethanol (13 billion liters per year) derived from fermentation by yeasts (sug ar cane being the basic raw material). Distilleries are recovering sur plus yeast to produce dry yeast for use in animal food formulations. W ith regard to the yeast biomass elemental composition, INAA analyses p erformed on a pool of samples from various different fermentations hav e shown the presence of various trace elements, e.g. As, Br, Ca, Ce, C o, Cr, Cs, Eu, Fe, Hf, K, La, Na, Rb, Sc, Sm, Th, and Zn. This reinfor ces the need for additional studies concerning the suitability of yeas t in terms of maximum tolerable levels of these elements in formulatio ns for domestic animals.