Determinação da composição em aminoácidos das proteínas da levedura de álcool (saccharomyces cerevisiae) seca e da farinha de peixe como ingredientes para rações de peixes de água doce

Abstract

Toe possible use ofmicrobial biomass to replace part ofthe fishmeal in fish diets could be considered an innovate solution. A quantitative determination of the content of amino acids was made in two protein sources: molasses yeast (S. cerevisiae) and fish meal. Toe chemical score and essential amino acid índex were calculated as a parameter correlated to biological value. Toe high lysine, threonine and tryptophan content of the protein in the molasses yeast must be emphasized. lt reaches an order of magnitude superior of that in fish meal. Further researches, especially in relation to protein digestibility and possible toxicity or antinutritional components in the molasses yeast, are certainly a warrant to access the nutritive value of yeast product for fresh water fishes before the acceptable dietary levei of these products can be recommended.