222 SPECIAL BACTERIOLOGY 



Biological Characters. Strongly anaerobic. In solutions of starch, 

 dextrin, sugar, and lactic acid salts a great quantity of butyric acid is 

 formed, accompanied by the development of H and CO 2 . 



BACILLUS BUTYRICUS (HUEPPE). 



Microscopical Appearances. Large rods, frequently occurring in 

 pairs. 



Spore Formation present, situated in the middle of the rods. 



Biological Characters. Grows in the presence of oxygen on the 

 ordinary media at both room and incubator temperature. 



Gelatine Media are quickly liquefied. 



On the surface of A gar Media, a moist yellowish coating. 



In Sterile Milk it develops best at incubator temperature, when 

 coagulation occurs similar to that produced by rennet, without the 

 reaction of the milk being changed. The casein is next dissolved and 

 changed into peptone and other products, ammonia being produced. 

 At the same time the milk acquires a bitter taste. This bacillus forms 

 butyric acid out of lactic acid salts. 



Bacteria causing Specific Changes in Beer, Wine, and Sugar. 

 BACILLUS VISCOSUS CEREVISLE (VAN LAER). 



Found in ropy beer, yeast, in the air, and on slimy bread. 



Microscopical Appearances. Rods 0-8 to 1-6 by 2 to 4 /z, seldom 

 occurring in chains ; said to form spores situated in the end of the 

 rods. 



Biological Characters. In Gelatine Stab Cultures the growth is 

 uniform along the inoculation track, and on the surface a diffuse white 

 growth develops. The colonies are sharply circumscribed, and when 

 examined under a low power appear brown coloured ; old colonies are 

 serrated, and in the middle, white, curly, and slightly thready. 



In Beerwort at 27 C. a germine ropiness occurs in twenty-four hours, 

 a large amount of CO 2 being formed ; the surface being studded later 

 with yellowish, ropy, slimy islets. 



Milk and Solutions of Peptone and Cane Sugar also become ropy, gas 

 being formed. 



On Potatoes, white, warty, viscous colonies develop, giving off a smell 

 like decayed fish. (Van Laer also describes another similar organism, 

 which is distinguished from the above by only producing slight 

 fermentation and ropiness.) The injurious influence of this organism is 

 only manifest when it obtains access to the wort before the primary 



