ENZYMES OF THE TUBERCLE BACILLUS 



139 



was added to make a volume of 12 cc, and, as antiseptic, 2 cc. 

 toluene and 1 cc. chloroform. After thoroughly mixing, this 

 was placed in the incubator at 37°C. for twenty-four hours, 

 centrifugated at the end of that time and the supernatant autol- 

 ysate withdrawn, filtered through a hard filter paper and divided 

 into two equal parts; one part heated for thirty minutes at 

 100°C., as control to destroy the enzymes, and the other half 

 kept intact. To each was added 1 cc. 0.1 per cent sodium casein- 

 ate, sodium carbonate to make 0.3 per cent, 1 cc. toluene and 

 1 cc. chloroform. The tubes containing these mixtures were 

 then incubated at 37°C., and a definite amount of the clear 

 watery solution withdrawn at various intervals and compared, 

 control and test, nephelometrically after precipitation with 

 sulphosalicylic acid. The results obtained, figured in percen- 

 tage of the heated control, were as follows: 



The above figures indicate a definite splitting of the casein 

 by the autolysate withdrawn at one day. 



(b) The above experiment la was repeated but the autolysate 

 was withdrawn after twelve days in the incubator at 37°C. The 

 results obtained with the autolysate as compared to the heated 

 control were: 



Percentage of original casein solution added. . . 



12 DATS 



71.4 



These figures indicate a definite hydrolysis of the casein by 

 the autolysate withdrawn at twelve days. 



(c) In order to check this point more fully a more complete 

 experiment was performed. Human tubercle bacilh, 2 cc. by 

 volume, were suspended in physiological salt solution to make 

 a total volume of 12 cc, and 2 cc. toluene and 1 cc. chloroform 

 added. The mixture was incubated for three days, centrifu- 



