ENERGY AND NITROGEN TRANSFORMATION 



507 



available from that part of the casein which has undergone de- 

 composition. 4 



The various other bacteria behaved in a similar manner, differing, 

 however, not only in the absolute amount of ammonia liberated, but 

 also in the ratio between the glucose consumed, casein decomposed 

 and ammonia liberated. Bac. mycoides liberated not only the largest 

 absolute amount of ammonia, but consumed a smaller amount of 



TABLE 45 



Influence of glucose on ammonia accumulation from casein in 400 cc. of synthetic 



solution in six days at room temperature 



ORGANISM 



B. subtilis 



B. proteus 



B. mycoides 



B .megatherium. . . 



B. vulgatus 



Sarcina lutea. . . . 



Casein 



Casein + glucose 



Casein 



Casein + glucose 



Casein 



Casein -f glucose 



Casein 



Casein -f- glucose 



Casein 



Casein + glucose 



Casein 



Casein + glucose 



BAC- 

 TERIA 



millions 



28.8 

 42.6 



62.4 

 67.7 



50.2 

 61.0 



57.8 

 87.9 



91.4 

 111.2 



14.7 

 15.6 



casein for a unit of ammonia liberated. Glucose brought about in 

 all cases an increase in the numbers of bacteria, but a decrease in the 

 amount of casein decomposed. 



4 It can be easily demonstrated in the case of fungi that the nitrogen content 

 of the organism is higher when the energy is obtained from proteins than when it 

 is obtained from carbohydrates. Further information on the influence of the 

 carbon source on nitrogen utilization by Bac. subtilis is found in a paper by 

 Aubel: E. A. Aubel. Influence de la nature de l'aliment carbone sur l'utilisation 

 de l'azote par le Bacillus subtilis. Compt. Rend. Acad. Sci., 171: 478^179. 

 1920. 



