Abstract
SUMMARY: The composition of the amino-acid pool of Saccharomyces cerevisiae is markedly influenced by the amino-acid nitrogen source. The yeast tends to accumulate the amino acid supplied and those closely related to it metabolically. A relatively high concentration of glutamic acid is maintained in the pools of all cultures irrespective of the nitrogen source, reflecting the central role of glutamic acid in nitrogen metabolism. The total amino-acid pool concentration increases as a function of growth rate, although differences exist in the behaviour of individual amino acids.