Bacillus Violaceus. 



B. VIOLACEUS BEROLINENSIS. VIOLET BACILLUS OF WATER. 



ORIGIN. Water of the river Spree at Berlin, and of the 

 Thames at London; also in well water. 



FORM. A slender rod about two to three times as long 

 as wide; it forms threads, but is usually in pairs. 



MOTILITY. It is actively motile. 



SPORULATION. Forms median spores. 



ANILIN DYES. React readily. 



GROWTH. This is moderately rapid. 



Gelatin plates. The colony is irregular with loose fibrillated bor- 

 der. The center shows quite early a violet color. It liquefies. 



Stab culture. Funnel-shaped liquefaction along the entire line of 

 inoculation. A violet sediment collects on the bottom, while the 

 liquefied gelatin above is perfectly clear. A violet ring may adhere 

 to the wall of the tube on the surface of the liquid. 



Streak culture. On agar, it forms a smooth, thin, moist, bright vio- 

 let covering. On potato, the growth is somewhat slow but very char- 

 acteristic, forming a bright violet, eventually dark covering. On 

 blood-serum, a violet color forms and liquefaction takes place. 



OXYGEN REQUIREMENTS. It is a facultative anaerobe. 

 Oxygen is necessary to pigment formation. 



TEMPERATURE. It does not grow at higher temperatures. 



BEHAVIOR TO GELATIN. Liquefies. 



PIGMENT PRODUCTION. This depends upon the presence 

 of oxygen. The color is soluble in alcohol, insoluble in 

 ether and in chloroform. It is changed to a green by min- 

 eral acids. 



PATHOGENESIS. It has no effect. 



About ten additional violet or blue pigment producing 

 bacilli are known. Some of these, however, may be mere 



varieties. 



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