Accumulation of Tripeptide Derivatives by Mutants of<i>Cephalosporium acremonium</i>

Abstract

The two β-lactam antibiotics produced by Cephalosporium acremonium ATCC 14553, cephalosporin C and penicillin N, have been proposed to be biosynthesized through the peptide, δ-(l-α-aminoadipyl)-l-cystemyl-d-valine. Many β-lactam negative mutants were derived from the strain No. 52, which was a more potent producer of the β-lactam antibiotics than the parent strain, C. acremonium ATCC 14553. Some of them were found to accumulate two sulfur-containing peptides. These compounds were isolated from the culture filtrate of one of the mutants, N-2 and determined to be the dimer of δ-(l-α-aminoadipyl)-l-cysteinyl-d-valine and the S-methylthio derivative of the tripeptide.