420 DESCRIPTION OF SOME SPECIES OF MILK BACTERIA 



Bacillus "b" of Guillebeau — Source 

 and characteristics as " a," differing 

 only in that Hquefaction of gelatine 

 is very slow, and the colonies are 

 viscid and sticky. 



Bacillus "c" of Guillebeau — Source 

 and characteristics as "a" and 

 " b," but does not liquefy gelatine. 

 Cultures very tough and slimy, 

 and colonies adhere to medium, 

 and are coarsely granular. Milk 

 becomes slimy until coagulation 

 begins. 



BACILLUS GUMMOSUS (Happ). 



Source and habitat — Isolated from 

 viscous vegetable infusion. 



Morphology — Bacillus, from 5 to 7-5 fj. 

 long by -6 io 2 IX broad. 



Motility — Feebly motile. 



Spore formation — Ovoid spores. 



Biology: cultural characters {includ- 

 ing biochemical features). 



Gelatine — Gelatine is rapidly 

 liquefied. The viscous matter 

 which is produced at the expense 

 of the sugar is soluble in water, but 

 insoluble in alcohol or ether ; with 

 it are found, as fermentation sub- 

 products, mannite, and lactic, and 

 butyric acids. This organism is 

 probably related to B. vulgatus 

 (Fliigge). 

 Non-pathogenic. 



BACILLUS HESSII (Guillebeau). 



Source and habitat — Milk. 



Morphology — Belongs to group of hay 

 bacilli ; small rod. 



Staining reaction — Ordinary aniline 

 stains. 



Capsule; motility — Actively motile ; no 

 capsule. 



Spore formation — Spores are not 

 described. 



Biology : cultural characters {includ- 

 ing biochemical features). 

 Bouillon — Becomes slimy. 



Potato — Dull white growth which 

 later becomes brown in colour. 



Milk — Coagulated into slimy 

 masses ; the stringy characteristic 

 of this slimy milk disappears after 

 2 days at 35° C. 



Non-pathogenic. 



BACILLUS LACTIS NIGER. 



Source and habitat — Milk. 



Morphology — Rods with rounded ends ; 

 •8 /tt broad, 2-8 to 2-6 fx long. Iso- 

 lated or united in pairs. 



Staining reaction — Ordinary aniline 

 stains and by Gram's method. 



Motility — Actively motile. 



Spore formation — Mesially situated. 



Biology : cultural characters {includ- 

 ing biochemical features). 



Bouillon — A yellowish veil ; the 

 liquid quickly clears. 



Gelatine plates — Young colonies 

 are grey, granular, and with 

 undulating prolongations into the 

 medium. As growth proceeds they 

 darken in colour and penetrate into 

 the medium, which liquefies with 

 great rapidity. 



Agar — A brownish yellow pel- 

 licle, the medium assumes a dark- 

 brown colour especially upon 

 glucose-agar. 



Potato — A humid brownish 

 growth, turning to brownish black, 

 the medium assumes a blackish 

 tint. 



Milk — Is coagulated in from 

 24 to 36 hours at 37° C, casein 

 subsequently redissolves almost 

 completely, the liquid remaining 

 clear. 

 Non-pathogenic. 



BACILLUS LACTIS PITUITOSI 



(Loffler). 



Source and habitat — Milk. 

 MoT^hology — Slightly bent rods. 



