Ethel M. Doidge 



71 



in the form of amino-acids and ammonia : if egg albumen contains 

 •150 grm. (approximately) total nitrogen, then 2-8 % of the total 

 nitrogen had been broken down ; after 10 days the figm'es were -007 grm. 

 or approximately 4-6 % of the total nitrogen. 



Milk cultures after ten days tested by the Sorensen method con- 

 tained -019 — -022 grms. nitrogen in the form of amino-acid and ammonia. 

 When tested by distillation for ammonia alone, practically the same 

 figures were obtained ; it was evident therefore that the amino-acids 

 had been reduced to ammonia. 



Tested qualitatively the milk culture gave a very decided reaction 

 for peptone and for ty rosin. 



The results recorded above are sufficient evidence that the organism 

 is a fairly active proteolytic agent. 



Amijlolyiic action. Potato cylinders on which the organism has been 

 growing for any length of time give the red-brown reaction for amylo- 

 dextrin when treated with Lugol's iodine solution rather than the 

 deep blue starch reaction. 



Tubes containing 10 c.c. nutrient bouillon and -01 grm. soluble 

 starch were planted with a vigorous culture and incubated at 25° C. 

 It was between two and three weeks before the starch totally dis- 

 appeared. The action of the organism on starch therefore is com- 

 paratively slow. 



Inverlase and lactase are not produced by this organism. This is 

 shown by the fact that although the organism produces acid in solutions 

 containing dextrose and galactose it is unable to do so in those con- 

 taining lactose and saccharose. Were it capable of reducing these 

 sugars, acid would be formed in solutions containing them. 



Fermentation reactions. No gas was produced in fermentation 

 tubes containing peptone water tinted with litmus and 2 % of various 

 carbohydrates. The amount of growth and presence or absence of 

 acid production may be scheduled as follows : 



