Absorption of Amino Acids From Wort by Yeasts

The absorption of α-amino acids from wort by various strains of yeasts followed a sequence which was almost independent of the conditions employed. The rate of absorption of arginine varied with the strain of yeast employed. The absorption of tryptophan and glutamic acid was affected by aeration. Proline, unabsorbed under “anaerobic” conditions was taken up during the latter part of the fermentation under aerobic conditions, and absorption was accompanied by the excretion of ninhydrin-positive material as yet unidentified. The use of worts containing an amino acid concentration in excess of a certain maximum resulted in the production of beers containing appreciable concentrations of the less readily assimilable α-amino acids.