THE TREHALOSE CONTENT OF BAKER'S YEAST DURING ANAEROBIC FERMENTATION* By W. E. TREVELYAN

In a previous study of the synthesis of cellular carbohydrate during fermentation by D.C.L. baker's yeast (Trevelyan, Gammon, Wiggins & Harrison, 1952) little variation was found in the trichloroacetic acid-soluble carbohydrate, of which the main constituent is trehalose (Trevelyan & Harrison, 1952). The low concentration of glucose in the medium used, about 5 mm, was thought to have restricted trehalose synthesis. The present paper reports measurements of trehalose in yeast during fermentation of high concentrations of sugar. As Brandt (1941) reported that trehalose disappeared rapidly from the yeast cell as a result of growth in a suitable medium, but increased in amount during metabolism in the absence of assimilable nitrogen, particular attention has been paid to the effect on yeast trehalose of nitrogenous constituents of the medium. Disappearance of trehalose during budding has been noted also by Pollock & Holmstrom (1951). Recently a study of some aspects of the connexion between carbohydrate and nitrogen assimilation in TorulOp8i8 utilie has been published by Yemm & Folkes (1954).