CHANGES PRODUCED BY A SAPROPHYTIC ANAEROBE 379 

 QUANTITATIVE ANALYSIS OF BIOCHEMICAL CHANGES 



Since the qualitative results left us in doubt concerning the 

 fermentatiun ability of these organisms, we attempted to deter- 

 mine these points by quantitative tests. 



Wolf and Harris (1917a; 1917b; 1918) and Wolf and Telfer 

 (1917) and Wolf (1918; 1919) have conducted exhaustive experi- 

 ments upon the biochemistry of pathogenic anaerobes from war 

 wounds, using quantitative methods. These authors did not 

 attempt to determine the ability of these organisms to ferment 

 many of the carbohydrates ordinarily used for the separation of 

 microorganisms into groups, and studied only those found in 

 wound infection. They did, however, collect some very valu- 

 able information concerning some of the activities of a large 

 number of the more common pathogenic anaerobes. 



We hoped, by tests of tliis sort, to determine some more accu- 

 rate and rapid method for the classification of anaerobes in 

 general, and those in particular with which we were working. 

 Since the dangers of botulism from the eating of canned foods is 

 more prev-alent than formerh^ it is quite essential that bacteriol- 

 ogists should obtain all the information possible concerning the 

 groups of spore-bearing anaerobic bacteria which may be found 

 in food. As has been mentioned above, the classification of 

 anaerobes is very much confused at the present time; and since 

 their fermentative ability, as determined by the ordinary quali- 

 tative methods is difficult to determine accurately, the only ap- 

 parent method of obtaining real differences is by quantitative 

 methods. 



We have, therefore, attempted to utilize the following quanti- 

 tative indications of difference: (1) Amount and kind of gas 

 produced from various carbohydrates; (2) amount and kind of 

 acid produced from various carbohj^drates ; (3) amount of pro- 

 teolytic action as determined by formation of ammonia and 

 amino-acids. 



The first condition to be fulfilled is to obtain a medium which 

 will be as constant as possible in composition, and one in which 

 organisms of this type are able to grow. The second condition 



