AN AEROBIC SPORE-FORMING BACILLUS GIVING 

 GAS IN LACTOSE BROTH ISOLATED IN 

 ROUTINE WATER EXAMINATION 



E. M. MEYER 



Laboratory for Field Investigations of Stream Pollutions, United States Public 

 Health Service, Cincinnati, Ohio 



Received for publication May 20, 1917 



In the course of routine water examinations at this station, 

 the writer has, on several occasions, isolated aerobic lactose- 

 fermenting organisms which have been demonstrated to be 

 spore-forming. So far as can be ascertained by a fairly complete 

 review of the published literature, there has been no such organ- 

 ism previously described.^ In water work two large groups of 

 bacteria generating gas from lactose are recognized. The first 

 are the aerobic non-spore-forming bacilli of the coli-aerogenes 

 group, and the second the anaerobic spore-forming bacilli of the 

 sporogenes group. The significance of the presence in a water 

 of members of either of these groups has been pretty well estab- 

 lished. The organism to be described lies midway between these 

 two groups, in that it is aerobic as well as spore-forming. Just 

 what its sanitary significance is, remains to be established, 



ISOLATION 



It has been the routine procedure in this laboratory to isolate 

 for study one culture of B. coli from each sample of water ex- 

 amined. This is effected by carefully fishing one isolated colony 



• Since this article went to press, the writer has come across an article on 

 systematic bacteriology of water by S. De M. Gage and E. B. Phelps in Am. 

 Pub. Health Ass. Rep. 1902, 28, 402, 412. In the table given in this article a few 

 cultures are noted as being aerobic lactose fermenters. In the opinion of Mr. 

 Gage it is very unlikely that the organism now being described could be among 

 those described by him. 



