ON THE GROWTH AND THE PROTEOLYTIC ENZYMES 

 OF CERTAIN ANAEROBES 



K. G. DERNBY and J. BLANC 



From the Pasteur Institute, Paris 

 Received for publication January 7, 1921 



In a work that soon will be published one of us, Blanc has 

 extensively studied the biochemistry of certain anaerobes, 

 especially Bacillus sporogenes and Bacillus histolyticus. It seemed 

 to be of interest also to introduce in that work the methods, 

 especially worked out in America by Clark and Lubs (1917) and 

 their followers, for studying the influence of hydrogen ion concen- 

 tration in its relation to growth and proteolytic activity. The 

 other of us, Dernby, has already in a series of papers used these 

 methods (Dernby 1918, Dernby and Avery 1918 and Dernby and 

 David 1920), and as we have limited this paper to as short a 

 communication as possible, we may for the description of methods 

 refer to these papers mentioned above. What will follow are 

 merely the main results of our work with some anaerobic micro- 

 organisms. 



Some time ago, Wolf and Harris and Wolf and Telfer (1917) 

 studied the biochemistry of the anaerobes, B. welchii (perfringens) 

 and B. sporogenes (Metchnikoff), taking into consideration the 

 influence of hydrogen ion concentration. It seems, however, 

 that they, like many other authors at that time, paid too much 

 attention to what is called ''the limiting hydrogen ion concen- 

 tration" and the influence of organic acids on the growth of the 

 microorganisms. In our opinion the first thing to do, when 

 studying the biochemistry of a given microorganism, is to deter- 

 mine the limiting and the optimal pH values for the growth of 

 this organism in a given medium. We by no means claim that 

 either of these values should be used as a new basis of classifying 



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