AMMONIACAL FERMENTATION OF URINE 223 



It forms oval spores, which resist a temperature of 95 for two 

 feours. It only grows satisfactorily in media containing urea or 

 ammonium carbonate, and at a somewhat high temperature, 

 namely, about 40 C. 



Urea-gelatine (p. 224). On this medium the colonies are very 

 small ; no liquefaction occurs. 



Bouillon containing ammonium carbonate becomes turbid and 

 ropy, with an unpleasant odour. 



Urobacillus Maddoxii, Miquel, is a motile bacillus, 3 to 6 ,u 

 long, i />t thick, isolated from river water and sewage. Oval 

 spores are found. It grows very poorly in bouillon or on gelatine 

 media ; even where the latter contains urea the development is 

 small, but crystal formation is recognizable. On ammoniacal 

 agar plates it grows better ; the colonies are thick and white. 



Urobacillus Freudenreichii, Miquel. A motile aerobic 

 bacillus, 5 to 6 p long and i ^ thick : it forms spores, and was 

 isolated by Miquel from soil, cow manure, and river water. 



Urea gelatine (p. 224). The colonies are round, white, non- 

 liquefying, and surrounded by a ring of crystals. 



Bouillon. In two to three days the medium becomes turbid, 

 later the cloudiness disappears, and a white precipitate is thrown 

 down. 



Ex. 103. Prepare the following urea-bouillon : 

 Water . . , - .' . 100 c.c. 

 Lemco's beef extract . . , 5 gr. 

 Witte's peptone . . . i.o gr. 

 Urea . . ... . 10.0 gr. 



Boil ; cool. The medium should be slightly alkaline ; if not, 

 add a drop or two of ammonium carbonate solution. Place 

 in a 250 c.c. flask and infect with a gram of garden soil, and 

 incubate at 20 to 30 C. for ten days. 



(a) Examine a drop of the fermenting medium from day to 

 day, and determine if cocci or bacilli are present. Stain with 

 gentian violet. At first Urococci or Planosardna may be present, 



