[Intracellular pool of free amino acids in a wild strain of Corynebacterium glutamicum and its lysine-producing mutants].

The intracellular content of free amino acids was measured in the wild-type strain of Corynebacterium glutamicum 13032 and its lysine producing mutants 410 and 133, resistant to the combined effect of threonine and S-2-aminoethyl cysteine, a lysine analog. After 18- and 48-hour cultivation of all strains the major components of the amino acid pool were glutamic acid, alanine and lysine, and those of the cell-free supernatant were alanine and lysine. After 18-hour cultivation the lysine content in mutants was 2-3 times higher than in the wild-type strain. After 48-hour cultivation the lysine content in mutants remained unchanged and in the wild-type strain increased. After 18- and 48-hour cultivation the lysine content in the supernatant of mutants was 15 and 33 times higher than in that of the parental strain. These findings are compared with the activities of aspartokinase from Cor. glutamicum 13032, 410 and 133.