BACILLI 461 



BACILLUS LIQUEFACIENS 



[TlQUEFIES GELATINE j 



Authority. Eisenberg, Bakteriologische Diagnostic, 1891, p. 112. The 

 B. liquefaciens described by Lustig (Diagnostik der Bakterien des Wassers, 189B, 

 p. 86) resembles very closely the above. 



Where Found. In water, and occurring very frequently (Lustig). 



Microscopic Appearance. Short and rather thick bacillus with rounded 

 ends. It is very motile. 



Cultures. 



GELATINE PLATES. Forms smooth-rimmed circular colonies, with white and 

 slimy contents, Liquefaction produces cup-shaped depressions which rapidly 

 increase in size. After a time an odour of putrefaction is perceptible. 



GELATINE TUBES. Grows, rapidly forming a funnel-shaped depression, which 

 towards the surface resembles an air-bubble in form. The needle's path in the 

 depth is filled with whitish granular material. 



AGAR-AGAR. Forms a dirty white expansion. 



POTATOES. Produces a light yellow growth. 



BACILLUS LIQUIDUS 



I LIQUEFIES GELATINE | 



Authority. Percy and G. C. Frankland, ' Ueber einige typische Mikro- 

 organismen im Wasser u. im Boden,' Zcitsclirift flir Hygiene, vol. vi., 1889, 

 p. 382. 



"Where Found. Very frequently in unfiltered river Thames water. 



Microscopic Appearance. Short flat bacillus with rounded ends, occurring 

 usually in pairs, the length of such a pair varying between 1-5 /w and 3'5 /u,. The 

 dimensions are very variable. It is very motile. No spore formation observed. 



Cultures. 



GELATINE PLATES. It forms large cup-shaped liquefying colonies, with 

 almost quite clear and colourless contents. Under a low power the depth 

 colonies are smooth-rimmed and circular. When liquefaction commences the 

 periphery becomes somewhat granular and serrated, and the colonies soon run 

 into each other. 



GELATINE TUBES. In a few days a broad funnel-shaped depression is visible 

 the whole length of the needle's path, containing turbid liquid and masses of 

 flocculent material. A thin pellicle forms on the surface later, which sinks to 

 the bottom on shaking the tube. 



AGAR-AGAR. Grows rapidly, forming a shining smooth expansion. 



POTATOES. Produces a thick, flesh-coloured, moist expansion. 



BROTH. Renders it turbid ; an abundant sediment collects, and after a few 

 days a pellicle forms on the surface. 



Remarks. Powerfully reduces the nitrates to nitrites. (See p. 27.) 



