194 BACTERIOLOGICAL AND ENZYME CHEMISTRY 



Mono-amino acids ; 

 Hydroxy-amino acids ; 

 Di-amino acids ; 

 Amino-dicarboxylic acids ; 

 Sulphur derivatives ; 

 Puiin bases ; 

 Ptomaines ; 

 Carboliydrates. 



In addition, simple substances such as sulphuretted hydro- 

 gen, carbonic acid, anunonia, sundry fatty and other acids, 

 etc., are produced. 



Mono-amino Acids 



The following are the chief mono-amino acids :— 

 1. Glycocoll or amino-acetic acid. — This is the simplest 

 member of the mono-amino acids ; it is frequently termed 

 glycin for the sake of convenience in describing its numerous 

 derivatives among the polypeptides. GlycocoU is related 

 to what is believed to be the mother substance of skatol, 

 a substance occurring in excreta, the unpleasant smeU of 

 which is largely due to it. Skatol can be recognised in 

 concentrated fresh sewage by the pink colour which is obtained 

 on warming with strong sulphuric acid. It has been shown 

 to be y8-methyl-indol, the relation of the two bodies skatol 

 and indol being given by the following formulse : — 



CI15 H 



\^c, /^-c 



;cH 



CH 



H H 



Skatol Indol 



