104 



Mr. E. C. Grey. Decomposition of 



Again, although the strain introduced at the beginning of the experiment 

 should remain constant during subsequent generations, as regards the 

 production of enzymes, yet the action of these enzymes would be modified by 

 the progressive change in the conditions resulting from the accumulation of 

 the products of their action. If such products affected equally all tlie 

 enzymes, then the result might simply be a slowing down of the fermentation 

 process as a whole, but if, as is more likely, the enzymes are differently 

 influenced, it may be that the course of the fermentation would vary from 

 time to time if a prolonged fermentation experiment were made. Grimbert 

 has shown this to be the case v/ith a bacillus producing butyric acid, and 

 Fernbach and Schoen have shown that the course of yeast fermentation can 

 be diverted into channels wherein there is a large production of acids, 

 especially interesting amongst which is pyruvic acid. 



It may perhaps be pertinent to remark in this connection that in all 

 experiments in which chalk or other alkali is added to the medium there is 

 probably a tendency to the encouragement of the action, if not of the 

 production, of acid-forming enzymes. 



Moreover, even if the enzymes introduced at the start remained constant 

 throughout the experiment and their actions were not selectively impeded by 

 the products of the fermentation or by other conditions, the experiment 

 would not serve to distinguish the products of one enzyme action from those 

 of another. To do this it is necessary to know whether the various enzyme 

 actions occur simultaneously or consecutively. In the first case, in order to 

 study one of the actions, it may be helpful to be able to arrange the conditions 

 so that the other reactions are brought to a standstill, and, in the second case, 

 it maj be that by reducing the period during which the fermentation is 

 studied, it is possible to separate the various phases from one another. Both 

 of these methods have been successful in the experiment described in this 

 communication. During the first period the conditions of the experiment 

 were accidentally such that the lactic acid enzyme did not act, and it was 

 possible therefore to observe which substances were produced independent 

 of it, and during the second 12 hours of the experiment it was possible to 

 observe the importance of the synthetic side of the fermentation process, this 

 period being really the period of rapid growth of the organism. 



The method of research here described indicates the means by which the 

 subject of the enzymes of bacteria can be more closely studied than has been 

 hitherto possible. 



Summary and General Conclusions. 



By analysis of the products resulting from the -decomposition of glucose by 

 B. coli communis, it has been shown that the fermentation is made up of 



