Utilization of Adenine by Yeast During Grape Juice Fermentation and Investigation of the Possible Role of Adenine as a Precursor of Urea

¹ Department of Viticulture and Enology, University of California, Davis, CA 95616-

Adenine utilization during fermentation of a Chenin blanc grape juice was investigated in two yeast strains, UCD 522 (Montrachet) and Prise de Mousse. Adenine was found to be consumed very early in the fermentation, prior to the onset of yeast growth, and slightly prior to the consumption of amino acids in both strains. Radioactively labeled adenine was utilized to determine if degradation of adenine yielded urea during the course of the fermentation. While significant amounts of unlabeled urea were produced during the fermentation, production of radioactively labeled urea could not be demonstrated for either strain. Thus, purine degradation does not seem to generate urea during the fermentation of grape juice.

Key words: yeast, adenine, urea, ethyl carbamate

Submitted on February 25, 1991