Lysine, methionine and tryptophan content of microorganisms.

As part of a survey to determine the suitability of microorganisms as sources of protein and amino acids, the lysine, methionine, and tryptophan in the cells of 271 strains of yeasts were determined. Yeast cells are an established source of proteins and vitamins in feeds. As a group, yeast possess certain advantages for large-scale propagation of cells. They can be grown easily on a variety of carbohydrate substrates and the cells can be separated conveniently from the culture liquor and dried. The lysine, methionine, and tryptophan contents of bacteria were reported in a previous publication (Anderson et al., 1958).