QUALITATIVE CATABOLIC REACTIONS OF BACTERIA 75 

 2. Production of phenolic bodies from tyrosine. 



OH 



+ NH 3 



Paraoxyphenyl propionic acid 



+ 3 O = 

 CH 2 .CHNH 2 .COOH CH 2 .CH 2 .COOH 



Tyrosine. Paraoxyphenylpropionic acid 



(deaminization) 



OH OH OH 



C0 2 + H 2 -> + C0 2 + C0 2 



Paracresol 



CH 2 .COOH CH 3 + 3 O = 



Paraoxyphenyl Paracresol. Phenol, 



acetic acid. 



Phenol is not oxidizable by bacteria, hence it remains as such 

 unchanged in the culture media. Phenol (or cresol) may be absorbed 

 from the intestinal tract, but it appears eventually in the urine as an 

 ethereal sulphate, precisely as indol appears in the urine as indican. 

 Indol and phenolic bodies are not found in cultures containing utiliz- 

 able carbohydrate the bacteria which produce indol and phenols 

 from tryptophane and tyrosine, respectively, can obtain their requisite 

 energy far more directly and economically from the sugar than from 

 the nitrogen-containing amino acid. Doubtless the same general 

 principle applies to the formation of these aromatic substances in the 

 intestinal tract. 



3. Formation of amines from amino-acids by bacterial action. 



(a) Cadaverin from lysine. 1 



CH 2 .CH 2 .CH 2 .CH 2 .CH.COOH CH 2 .CH 2 .CH 2 .CH 2 .CH 2 



I I - I I- +C0 2 



NH 2 NH 2 NH 2 NH 2 



Lysine. Cadaverin. 



(6) Putrescin from ornithin. 2 



CH 2 .CH 2 .CH 2 .CH.COOH CH 2 .CH 2 .CH 2 .CH 2 



| | -'/ "! I +00, 



NH 2 NH 2 NH 2 NH 2 



Ornithin. Putrescin. 



1 Ladenburg, Ztschr. f. phys. Chem., 1886, xix, 780. 



2 Ellinger, Ztschr. f. phys. Chem., 1902, xxix, 334; Ber. d. deut. chem. Gesell., 1889, 

 xxxi, 3183; ibid., 1900, xxxii, 3542. 



