1964.-a mutant of escherichia coli k-12 , capable of excreting 350 mg of indole and 50 mg of tryptophan per liter when grown on minimal medium , was found to have a level of 3-deoxy-d-arabino-heptulosonic acid-7-phosphate ( dahp ) synthetase 60 % higher than the parent , and to have a 10- to 15-fold elevation of the levels of enzymes in the tryptophan branch of the pathway for aromatic amino acid biosynthesis .
C0041249
tryptophan
C0301713
aromatic amino acid