1. A further fraction of ;cell-bound exopenicillinase9, in addition to that bound ionically to the surface of the cell wall, has been identified in Staphylococcus aureus. 2. Treatment of cells with low concentrations (0.01m) of organic anions liberates part of this exopenicillinase, such liberation being dependent on both time and temperature, but independent of an external supply of energy. 3. Tricarboxylic acids tend to be more effective than dicarboxylic or monocarboxylic, although there are large differences between ionic species even when tested at the same normalities.
