GROWTH OF CERTAIN ANAEROBES 425 



II. THE PROTEOLYTIC ACTIVITY OF FILTRATES FROM CLOSTRIDIUM 

 SPOROGENES AND CLOSTRIDIUM HISTOLYTICUM 



It is well known that anaerobes of this type are strongly pro- 

 teolytic, dissolve fibrin and casein, liquefy gelatin, disintegrate 

 pepton, and so on. The present mode of classifying the pro- 

 teolytic enzymes seems to be to determine (1) the substrates 

 attacked, (2) the products of digestion and (3) the optimal hydro- 

 gen ion concentration for the action. The two best substrates, 

 which can be used in solution, are gelatin and pepton. In the cited 

 paper by Dernby (1918) the method for using these substrates 

 is fully described. Below we have studied the proteolytic 

 activity of Clostridium sporogenes and Clostridium histolyticum. 

 As enzyme the broth culture after passing a Chamberland 

 filter has been used. By this method, we of course get in- 

 formation only in regard to the ''ekto" enzymes, whereas the 

 ''endo" enzymes will escape our attention. The ideal thing 

 would be to obtain large quantities of the bacilli, let them auto- 

 lyze and determine the proteolytic activity of the autolysate. 

 It is possible that in that case we should obtain enzymes both 

 of the pepsin and of the trypsin-erepsin group as has been found 

 is the case of yeast (Dernby, 1917). 



The filtrates were obtained in the following way: For each cul- 

 ture 500 cc. of an ordinary broth made from autolyzed veal was 

 taken, 1 per cent glucose and enough NaOH to render the initial 

 reaction almost neutral (pH 7) were added. The mixture was 

 sterihzed at 107° for an hour. After cooling to 37° the flasks 

 were inoculated with the microorganism in question, and simul- 

 taneously a minimal dose of solid calcium sulphide was added. 

 The flasks were allowed to stand in the incubator at 37° for 

 seventy-two hours, and then 3 cc. of chloroform were added. The 

 culture was first filtered through paper and thereafter passed 

 through a Chamberland filter. The clear filtrate was kept sterile 

 at room temperature, and exhibited strong proteolytic activity 

 for several months. 



