Induction of penicillin biosynthesis by L-glutamate in Penicillium chrysogenum

Abstract

The effect of L-glutamate on penicillin formation by Penicillium chrysogenum was investigated. This amino acid (10 mM) strongly stimulated the specific antibiotic formation in regard to systems containing similar concentrations of either NH4Cl or L-glutamine as nitrogen source. No stimulation was achieved when in addition to glutamate the system contained cycloheximide. Nonmetabolizable analogues of the amino acid also stimulated antibiotic formation. At the enzymatic level, L-glutamate caused a 3.5 fold increase in δ(L-α-aminoadipyl) L-cysteine synthetase concentration, therefore we concluded that the amino acid stimulated penicillin formation through induction of this enzyme.