1989 Volume 42 Issue 9 Pages 1416-1423
The phenylacetic acid (PA) transport system in Penicillium chrysogenum is an induciblesystem (see FERNÁNDEZ-CAÑÓN et al.; preceding papers) which is repressed by free amino acids when these molecules are added to the complex fermentation broths at the induction time. L-Tyrosine, L-α-aminoadipic acid, L-tryptophan, L-phenylalanine and L-methionine are the molecules that cause the greatest delay in induction. The addition of Krebs-cycle intermediates to the complex fermentation broth did not affect the rate of induction with the exception of oxalacetic acid and citric acid which strongly increased it. Ammonium salts and acetate also repressed the biosynthesis of the enzymes involved in the PA uptake.
