A Diazotizable Amine Produced by Yeast: its Chemical Nature and Factors Affecting its Accumulation

SUMMARY: The effect of area:volume ratio and composition of medium on the accumulation of diazotizable amine ( ‘ amine ’) and hypoxanthine by yeast 47 growing in biotin-deficient medium are reported. The ‘ amine ’, isolated from culture filtrates by mercury precipitation and separation on ion exchange resins, gave the Pauly reaction for imidazoles: on acid hydrolysis it yielded ribose, glycine, ammonia and formic acid, but no phosphate. These properties are consistent with the view that the ‘amine ’ is 5-amino-imidazole riboside or a closely related compound. When the growth medium contained 500 pg. L-aspartic acid/ml., instead of ‘amine ’ and hypoxanthine, substances accumulated which on hydrolysis yielded adenine as the only purine. ‘Amine ’ accumulation by yeast 47 may be a symptom of a derangement of purine metabolism resulting from a biotin-conditioned block in aspartate synthesis. Previous papers from this laboratory (Chamberlain, Cutts & Rainbow, 1952; Chamberlain & Rainbow, 1954) reported that a diazotizable amine ( ‘ amine ’) and hypoxanthine accumulated in culture filtrates of Saccharomyces cerevisia