[Comparative study of the protective qualities of some protease inhibitors in the drying of Cl. oedematiens type B toxin].

A comparative study was carried out on the lethal properties of dry toxins of Clostridium oedematiens Type B obtained by means of salting cultural Seitz-filtrates, containing or lacking protease inhibitors, being dried for 24 and 48 hours at 37 degrees C. It was found that when ammonium sulfate was used for salting, the dry toxins from such filtrates, containing 0.0001 gram% specific soya inhibitor, showed 2 to 300 times higher toxicity than those containing no inhibitor. The addition of 3 per cent normal horse serum to the cultural filtrates of Clostridium oedematiens Type B favoured the production of dry toxins of higher lethal properties. The decrease in the lethal properties of a dry toxin without inhibitor was found to be in a positive correlation with the drying term and the residual moisture of the toxin. When a protease inhibitor was employed the drying term had no effect on the activity of the dry toxins.