Production of D-amino acid oxidase by Aspergillus sp. strain O20 active on cephalosporin C

Aspergillus sp. strain O20 produces inducible D-amino acid oxidase intracellularly. only in the presence of some amino acids. The enzyme was induced most effectively by the addition of DL-alanine (1% w/v) to the production medium. Among the various compounds studied, production of the D-amino acid oxidase was enhanced by Aerosol-22, glucose. and sodium nitrate. D-Amino acid oxidase formation was observed during the onset of the stationary growth phase. Maximum enzyme activity was recorded after 96 h of fermentation (1000 IU/L).