NATURE OF BACTERIOLVSANTS 



501 



of normal strains of dysentery bacilli were bacteriolytic their 

 activity was extremely weak. 



BACTERIOLYTIC ACTIVITY OF FILTRATES OF A PEPTONE WATER 

 CULTURE OF BACT. SUBTILIS 



NicoUe (Davison, 1922) reported that cultures of B. subtilis 

 and their filtrates, were bacteriolytic for several types of organ- 

 isms. As he had not tested the bacteriolytic activity of B. 

 subtilis against Flexner bacilli, I did so. As shown in table 14, 

 the filtrate of a culture of B. subtilis (obtained from a contam- 

 inated plate) was not bacteriolytic for Flexner bacilli but the 



TABIj; 14 

 Dacleriolytic activily offiUrates of peptone water cultures of B. subtilis 



FILTRATE OB SUflPEKSION t'SED 



Filtrate of four-day peptone water culture of B. subtilis 

 Filtrate of peptone water culture of normal dysentery bacilli 

 which had been incubated forty-eight hours with the filtrate 

 of B. subtilis culture (above) 

 Filtrate of eighteen-day peptone water culture or normal dys- 

 entery bacilli which had been intentionally contaminated 

 with B. subtilis 



BACTERIOLTTIC 

 ACTIVITY Oy 

 FILTRATE OB SUS- 

 PENSION AUAIN&r 



NORMAL 

 FLEXNER BACILLI 







± 



filtrate of a normal dysentery culture to which the filtrate of a 

 B. subtilis culture had been added, or which had been inten- 

 tionally contaminated with B. subtilis, was ' sUghtly bacterio- 

 lytic. However this bacteriolytic activity was no more marked 

 than that of filtrates of normal dysentery bacilli to which nothing 

 had been added (table 13) so it is improbable that B. subtiUs 

 or its filtrates can lyse Flexner bacilU. 



ABSENCE OF BACTERIOLYTIC ACTIVITY IN TRYPSIN 



As the optimum reaction for bacteriolysis apparently coin- 

 cides with that of the enzyme, trypsin, I tested the bacteriolytic 

 activity of solutions of trypsin and also compared the action on 

 gelatin of trypsin, bacteriolysants and "sensitive" and normal 

 strauis of Flexner bacilli. 1 per cent and 5 per cent solutions of 



