CHAPTER 



FERMENTATIONS OF 

 NITROGENOUS COMPOUNDS 



In 1934 the biochemical transformations involved in the 

 anaerobic breakdown of nitrogenous compounds had not 

 been extensively studied. Various proteinaceous materials 

 were known to undergo extensive decomposition in the 

 absence of oxygen with the formation of ammonia, carbon 

 dioxide, fatty acids, hydrogen sulfide, and an assortment 

 of other volatile substances frequently having unpleasant 

 or repulsive odors. Such "putrefactive" processes had been 

 found to be caused mainly by Clostridia, several species of 

 which had been shown to grow in media containing proteins 

 and amino acids but no carbohydrates. However, very little 

 information was available concerning the specific reactions 

 catalyzed by individual species. The reasons for this are 

 not hard to find. With some conspicuous exceptions, most 

 of the studies in this area had been done either by chemists 

 who disregarded one of the basic requirements for sound 

 microbiological work, namely the use of pure cultures, or 

 by bacteriologists who were unequipped to handle the fre- 



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