58 THE CHEMISTRY OF BACTERIA 



Another type of bacterial activity of importance is the oxidation 

 of ammonia, the final step in the degradation of protein, into nitrites 

 and nitrates. This is carried on by the nitrifying bacteria of the soil. 

 Contrary to the generally accepted idea, therefore, the activities of 

 the majority of bacteria are not in opposition to the activities of man, 

 animals, and plants; bacteria are indispensable agents in the economy 

 of nature. 



B. CHEMICAL COMPOSITION OF BACTERIA. 



1. Elementary Composition. Bacteria normally contain the same 

 elements in their substance that the higher plants and animals contain, 

 viz., carbon, nitrogen, hydrogen, oxygen and phosphorus, together 

 with smaller amounts of sodium, chlorine, sulphur, potassium, calcium, 

 magnesium, and traces of iron. 



2. Chemical Constitution. The elements carbon, hydrogen, nitro- 

 gen and oxygen, and to a certain extent phosphorus, and perhaps 

 sulphur are united to form proteins, nucleoproteins, carbohydrates, 

 and fats. The inorganic substance of bacteria is made up of the other 

 elements mentioned above in variable proportions. Of these elements, 

 carbon, hydrogen, nitrogen, oxygen and phosphorus are the most 

 important. 1 



TABLES ILLUSTRATING THE CHEMICAL COMPOSITION OF 

 BACTERIA. 



1. PERCENTAGE OF THE ELEMENTS IN ASH-FREE " MYCOPROTEiN." 2 



C H N 



per cent. per cent. per cent. 



52.1-52.6 7.3-7.38 14.5-14.9 



2. PERCENTAGE COMPOSITION WITH RESPECT TO ORGANIC AND INORGANIC 

 CONSTITUENTS. 



Putrefactive Bacillus Tubercle 



bacteria. 3 prodigiosus. 4 bacilli. 5 



Water 83.42 85.45 85.00 



Protein 13.96 10.33 8.50 



Extractive 1.00 0.70 4.00 



Ash 0.78 1.75 1.40 



Residue. 0.84 1.77 1.10 



1 Certain acid-fast bacteria can be grown in media containing theoretically but five 

 elements: carbon, hydrogen, nitrogen, oxygen, and phosphorus. Lowenstein, Centralbl. 

 f. Bakteriol., Original, 1913, Ixviii, 591. Wherry, Centralbl. f. Bakteriol., 1913, Ixx, 

 115. Kendall, Day and Walker, Jour. Inf. Dis., 1914, xv, 428. 



2 Kruse, Allgemein. Microbiol., p. 62. 



3 Nencki and Scheffer, Ueber die chemische Zusammensetzung der Faulnisbakterien, 

 Beitr. z. Biol. d. Spaltpilze. Nencki, Leipzig, 1880, Jour. f. prakt. Chemie, N. F., xix, 



U. XX. 



4 Kappes, Analyze d. Massen Kulturen einiger Spaltpilze u. d. Soorhefe, Leipzig, Diss., 

 1889. 



6 Ruppel, Die Proteine, 1900, Heft 4, Beitr. z. exp. Therapie., Ztschr. f. physiol. 

 Chemie, xxvi. 



