FORMATION OF EXTRACELLULAR LYSINE BY USTILAGO MAYDIS AND GLIOCLADIUM SP.

Abstract

A strain of Gliocladium sp. and a strain of Ustilago maydis produced approximately 400 μg./ml. of extracellular lysine in shaken Erlenmeyer flasks. In U. maydis growth media, most of the extracellular lysine, arginine, and histidine is in the free form. Metabolic studies show the lysine to be formed during early growth, concurrent with the formation of most of the extracellular organic nitrogen. The extracellular organic nitrogen and lysine is used during a late growth surge in experiments showing high lysine concentrations but not in those showing low lysine concentrations.None of the compounds tested as precursors or intermediates resulted in an increased concentration of extracellular lysine.