FACTORS INFLUENCING DEATH OF BIOTIN-DEFICIENT YEAST CELLS

Biotin-requiring baker's yeast died when aspartate was given to biotin- deficient cells harvested in later stage of exponential growth. The cells before addition of aspartate had no aspartic acid in the pool. After its addition, the cell components were rapidly synthesized and cells began to bud. However the budding cells lost the ability to multiply before nucleus was transferred to the bud cell, the amount of whose DNA increased approximately twice. Death did not occur at neutral pH or under an increased osmotic pressure of the surrounding fluid. This death was accelerated in the presence of chelating agents. The accelerating effect disappeared immediately on eliminating the chelating agents from the biotin-free medium. The site of action of chelating agents seems to be restricted only to the cell surface.