430 K. G. DERNBY AND J. BLANC 



ion concentration are almost identical. Whether it is the same 

 tryptase that acts in both cases, or whether there are several 

 is impossible to say. 



The conclusion we have arrived at by these experiments is 

 simply that the proteolytic enzymes in filtrates from Clostridium 

 sporogenes and Clostridium histolyticum seem to be very much 

 alike, and that the enzymes which can be detected belong to the 

 tryptase group. 



It must be remembered however that in the living or dead 

 microorganisms there are also present proteolytic enzymes of 

 other types. 



SUMMARY 



The opthnal and limiting hydrogen ion concentrations for the 

 growth of the anaerobes, Clostridium sporogenes, Clostridium 

 histolyticum, Clostridium canadiense, Clostridium putrificum and 

 Clostridium perfringens have been determined. The range in 

 which all of these organisms live has the limits pH 5 to pH 9. 

 The optimum range for all seems to be at or about the neutral 

 point pH 7 and is apparently a rather broad one. 



2. The proteolytic activity of filtrates from Clostridium sporo- 

 genes and Clostridium histolyticum has been studied. Gelatin 

 is liquefied and pepton is disintegrated in the range pH 4 to pH 8, 

 and the optimum for both these reactions seems to be about 

 pH 6. The conclusion is that in the filtrates a tryptase is present. 



REFERENCES 



Clark, W. M., and Lubs, H. A. 1917 Jour. Bact., 2, 1. 

 Dernby, K. G. 1917 Biochem. Z., 81, 109. 

 Dernby, K. G. 1918 Jour. Biol. Chem., 35, 179. 

 Dernby, K. G., and Avery, O. T. 1918 Jour. Exp. Med., 28, 345. 

 Dernby, K. G., and David, H.: 1920. 



Wolf, Ch. G., and Harris, J. 1917 Jour. Path, and Bact., 21, 385, and Bio- 

 chem. Jour., 11, 213. 

 Wolf, Ch. G., and Telfer, S. V. 1917 Biochem. Jour., 11, 297. 



