THE PRODUCTION OF VOLATILE FATTY ACIDS BY BAC- 

 TERIA OF THE DYSENTERY GROUP. 



By harper F. ZOLLER and W. MANSFIELD CLARK. 



(From the Research Laboratories of the Dairy Division, Bureau of Animal Industry, 

 United States Department of Agriculture, Washington.) 



(Received for publication, October 11, 1920.) 

 INTRODUCTION. 



In the course of an investigation of bacteria of the dysentery group 

 we had occasion to determine the volatile fatty acids produced by 

 these bacteria under different conditions. We beheve the results to 

 have considerable significance but their interpretation had best 

 wait upon the development of more fundamental knowledge of 

 anaerobiosis than we now possess. We therefore desire to place the 

 following data on record without comment. 



Organisms Studied — The cultures were secured from several investi- 

 gators and institutions and represented the usual types together with 

 some atypical organisms. A laboratory fire destroyed the history of 

 each culture, but they have been separated into Shiga and non-Shiga 

 types by mannite fermentation tests through the cooperation of Dr. 

 J. M. Sherman of this laboratory. Fermentation data were at hand 

 which would permit the differentiation of the non-Shiga cultures into 

 Flexner, Strong, and other strains; but this was not done, since the 

 results of the volatile acid work are in such close agreement that, as 

 conducted, they have no important bearing upon the classification of 

 the dysentery bacteria. The results from one each of typhoid (Ty 

 Round). and paratyphoid (P Ty 16) cultures are included because of 

 the relation existing between the dysentery and these groups of 

 organisms. Following the laboratory number will be found the 

 strains studied: Di, Flexner; D2, Shiga; D3, Shiga; D4, Flexner; Dg, 

 Shiga; De, non-Shiga; Ds, non-Shiga; Dio, non-Shiga; Du, noii-Shiga; 

 Di3, non-Shiga; D17, non-Shiga; D23, non-Shiga; D24, Shiga; D33, 

 non-Shiga; D37, Shiga. 



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