96 



ity from the first period until the last, except the lactic acid bacillus 

 which produced its maximum acidity within the first period (four days) 

 which was 1.61 per cent, as lactic acid. No change in acidity occurred 

 after this period, nor was there any increase in ammonia. The amid 

 nitrogen increased slightly at the expiration of four days and there was 

 a agin of amid nitrogen of .0077 per cent, and at the expiration of the 

 sixteenth day there was a gain of .0105 of amid nitrogen, a gain of .5 

 per cent, on total nitrogen, showing a continual proteolytic action due 

 either to enzymes or auto-proteolytic digestion. 



It may be noted that some bacteria utilizing the larger amount of 

 lactose were also qidte active in the production of ammonia and amino 

 acids. On the other hand, in Table III the fermentation of lactose was 

 proportionately greater than the production of ammonia and amino acids 

 by B. proteus, B. butyricus, B. mesentericus, B. fluorescens put., and B. 

 Coli. 



We hope to study further the action of these organisms in pure cul- 

 ture on nitrogen from different sources, the effect of carbohydrates and 

 also the associative action of these cultures on milk proteins. 



