Carbonic Anhydrase

Abstract

Concentrates of red-blood-cell extracts containing carbonic anhydrase in an incompletely purified form have 2, contrasted, effects on the growth of Type I pneumococcus in broth. A marked growth-retarding effect becomes lost, together with the carbonic anhydrase titer, on heating to 80[degree] C. An opposed, growth-accelerating effect survives heating to 80[degree] C but becomes lessened by a degree of dialysis without parallel effect either on carbonic anhydrase titer or on growth-retarding activity. Decreases in temp. of incubation and increases in initial CO2 content, which tend to increase opportunity for carbonic anhydrase action, and a degree of impoverishment of the medium tending to increase the sensitiveness of the pneumococcus to C02 loss, increase the growth-retarding effect following addition of carbonic anhydrase concentrates. No carbonic anhydrase is present in an autoclaved broth medium free of added fresh blood; nor is carbonic anhydrase produced during the growth of the Type I pneumococcus or Staphylococcus aureus in such a medium. No substantial destruction of the carbonic anhydrase present in added crude concentrates is apparent as the result of moderate pneumococcal growth in broth at 30[degree] C. The growth-retarding action is apparent following additions of concentrate, to 10 ml. of broth, corresponding in carbonic anhydrase activity to 0.8 ml. or more of whole blood, but not following additions of 1/10 of that amt.