Reprinted from THE JOURNAL OF THE AMERICAN WATER WORKS ASSOCIATION 

 Vol. 9, No. 2, March, 1922 



A FACULTATIVE SPORE-FORMING LACTOSE-FERMENT- 

 ING ORGANISM FROM IOWA SURFACE WATERS, 

 (B. MACERANS) 1 



BY JACK J. HINMAN, Jn., 2 AND MAX LEVINE S 



The occasional presence of sporing lactose-fermenters in water 

 capable of growing aerobically has been reported by Meyer, Ewing, 

 Ellms, Perry and Monfort, and Hall and Ellefson, but very little 

 is known as to the source or biology of these forms. 



In the course of routine water analyses at the Iowa State Water 

 Laboratory it appeared that, with chlorinated surface waters the 

 proportion of unconfirmed presumptive tests was excessive, when 

 using preliminary enrichment in lactose broth, and eosin methylene 

 blue agar for confirmation. With litmus lactose agar, however, 

 atypical colonies were not infrequently obtained, which often formed 

 gas when fished to lactose broth and which would therefore be re- 

 garded as members of the colon group, on the basis of the Treasury 

 Department Standard. These organisms were invariably negative 

 for gas formation in lactose bile. It occurred to us that possibly 

 aerobic sporing lactose bacilli might be responsible, for a part at 

 least, of these atypical reactions, and attempts were made to isolate 

 them. 



Table 1 has been prepared to show the frequency with which 

 presumptive tests upon filtered, chlorinated Iowa city waters were 

 found to be organisms which could not be confirmed as B. coli or 

 B. aerogenes. It appears that those waters which were taken from 

 the Iowa River, or from the Mississippi River below the junction of 

 the Iowa with the Mississippi, are particularly likely to contain 

 these non-confirmed organisms. This apparent peculiarity may be 

 due, however, to the greater number of samples examined from the 

 cities of Burlington, Iowa City and Keokuk where such water is 

 handled. 



1 Presented before the Iowa Section meeting, November 1, 1921. 

 * Associate Professor of Sanitation, State University of Iowa. 

 Department of Bacteriology and Pathology, Iowa State College. 



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