EFFECT OF NITROGEN SOURCE ON GROWTH AND EXOPROTEASE PRODUCTION BY Clostridium perfringens

16 strains of Clostridium perfringens were screened for their growth and exoprotease activity in a synthetic amino acid medium (R + S) and in media containing either vitamin‐free casein, spray‐dried whole egg or ground frankfurter as the protein source. Growth, measured by gas production, was determined manometrically under standard conditions. Quantitative enzymatic assay of sterile culture filtrates was carried out at pH 7.0 using Azocoll general proteolytic substrate. Strains grown in protein‐containing media usually produced more exoprotease per unit of growth than strains grown in synthetic amino acid medium. Strains which constitutively produce high levels of exoprotease were identified.