Role ofp-Aminophenylalanine in Biosynthesis of Corynecins and Aromatic Amino Acids byCorynebacterium hydrocarboclastus

Abstract

Identification of p-aminophenylalanine (PAP) was made in the culture broth of Corynebacterium hydrocarboclastus and its intracellular pool decreased as progress of Corynecin production. The specific inhibitor of Corynecin biosynthesis, p-aminophenylethylalcohol, caused the accumulation of PAP as well as other aromatic amines related to Corynecins. Variation of PAP pool was consistent with properties as the precursor of Corynecin. Addition of PAP to the medium did not increase the amount of Corynecin production, suggesting that the biosynthesis of Corynecins might be regulated at stages after the formation of PAP. Growth inhibition by PAP added to the medium was observed (5 mm for 50% inhibition) and this inhibition was relieved by the addition of tyrosine and phenylalanine but not by shikimate, prephenate or tryptophan, showing that PAP did not inhibit the pathway before the formation of prephanate. These effects of PAP on shikimate pathway seem to be preferable for efficient production of Corynecins.