Methionine Metabolism and Cephalosporin C Synthesis in Cephalosporium acremoniumd‐Amino Acid Oxidase

The d ‐amino acid oxidase was produced during the growth cycle of Cephalosporium acremo‐nium in submerged culture. The enzyme is strictly sterospecific for d ‐amino acids as substrates. It was isolated from the mycelial crude extract and purified 18‐fold. A relatively small number of d ‐monoamino acids were deaminated. With d ‐methionine as substrate the enzyme had a pH optimum of 8.5 and it was competitively inhibited by the d ‐stereoisomers of norleucine, norvaline, leucine, isoleucine, phenylalanine and lysine. The properties of the C. Acremonium enzyme are compared with those of other fungi and mammalian d ‐amino acid oxidases. Its possible influence on the biosynthesis of the antibiotic Cephalosporin C is discussed.