THE NITROGEN CYCLE 447 



findings of Marchal 1 may be taken as representative 

 of the process of ammonification. He found that when 

 this bacterium was seeded on a neutral solution of albumin, 

 ammonia and carbon dioxide were produced, together 

 with small amounts of peptone, leucine, tyrosine, and 

 formic, butyric, and propionic acids. He concludes that 

 in the process, atmospheric oxygen is used, and that 

 the carbon of the albumin is converted into carbon dioxide, 

 the sulfur into sulfuric acid, and the hydrogen partly 

 into water, and partly into ammonia by combining 

 with the nitrogen of the organic substance. He suggests 

 that a complete decomposition of the albumin occurs 

 according to the following reaction : 



C72H 112 Ni 8 S022 + 77 O 2 



= 29 H 2 + 72 C0 2 + SO 3 + 18 NH 3 



The greatest activity occurred at a temperature of 86 

 F., and as low as 68 F. action was rather strong. Access 

 of an increased amount of air, produced by increasing the 

 surface of the liquid, increased the rate of ammonification. 

 A slightly acid reaction in the liquid produced the maxi- 

 mum activity, but in a neutral or even slightly acid me- 

 dium the process was continued, although much less 

 actively. 



Marchal found that B. mycoides was also capable of 

 ammonifying casein, fibrin, legumin, glutin, myosin, 

 serin, peptones, creatine, leucine, tyrosine, and asparagine, 

 but not urea. 



368. Nitrification. Some agricultural plants can util- 

 ize ammonium salts as a source of nitrogen. This has 



1 Marchal, E. Sur la Production de I'Ammoniaque dans 

 le Sol par les Microbes. Bulletins de 1'Acad. Royale de Belg., 

 3 series, F. 25, pp. 727-776, 1893. 



