RESULTS OF BACTERIAL GROWTH 23 



The enzymes produced by bacteria are probably responsible 

 for all the processes of disintegration to which they give rise. 

 Two general forms are recognized : fermentation and putrefaction. 

 The term fermentation is usually applied to the breaking down 

 of carbohydrates into alcohol, acids, carbon dioxide, etc. Putre- 

 factive decomposition is the term applied to the breaking down 

 of nitrogenous substances. It is generally thought that bacterial 

 action on proteins closely resembles that of the digestive enzymes 

 of the animal alimentary tract. The proteins are decomposed 

 into : proteoses, peptones, amino-acids, etc., often with end- 

 products such as skatol, mercaptan, and sulphureted hydrogen. 

 Ordinarily these processes are carried on by aerobic and anaerobic 

 bacteria living in symbiosis. 



