440 DESCRIPTION OF SOME SPECIES OF MILK BACTERIA 



edge becomes light and surrounded 

 by liquefaction. In stab-culture 

 a narrow funnel is produced con- 

 taining a dense cloudy liquid. 



Agar plates and tubes — An 

 almost snow-white growth is pro- 

 duced. 



Potato — Thin and watery growth 

 produced, spreading over surface. 



Milk—\s curdled at 36° C. in 3 

 days with amphoteric reaction. 

 Curdles in 3 weeks at 20° C. The 

 curd is soft with no whey, and 

 subsequent digestion is slight. 



Non-pathogenic. 



MIOROOOCOUS FRBUDBNRBICHII 



(Guillebeau). 



Source and habitat — Viscous milk. 



Morphology — Large cocci ; more than 

 2 M in diameter ; usually single, 

 more rarely in chains, like a strepto- 

 coccus. 



Staining reaction — Ordinary stains. 



Motility — Non-motile. 



Biology : cultural characters {includ- 

 ing biochemical features') — Growth 

 occurs at any temperature from 

 ii°C. to 35° C, 



Bouillon — At first becomes 

 cloudy and then clear, with a 

 flocculent deposit. 



Milk gelatine — Round, white 

 colonies, finely granular ; after 2 

 days rapid liquefaction occurs. 



Agar — A white growth. 



Potato — A sulphur-yellow col- 

 oured growth, at times of brownish 

 tint, often luxuriant. 



Milk — Becomes tenacious and 

 sticky with the formation of acid ; 

 coagulation occurs after a few days. 



Aerobic. 



Non-pathogenic. 



MICROCOCCUS GIGANTBUS 

 LACTIS (Conn). 



Source and habitat — Milk. 



Morphology — Coccus ; very large, 

 1-5 yu. in diameter. 



Staining reaction — Ordinary aniline 

 stains. 



Biology : cultural characters {includ- 

 ing biochetnical features). 



Bouillon — No visible growth. 



Gelatine plates and tubes — An 

 opaque white colony, not character- 

 istic. In stab-culture an abundant 

 "needle growth," but no surface 

 growth. 



Agar plates and tubes; potato — 

 No visible growth. 



Milk — ^ No effect upon milk, 

 except that after 4 weeks very 

 slight acid, reaction and curdling 

 takes place. 



Anaerobic. 



Non-pathogenic. 



MICROCOCCUS LIQUEPACIBNS 

 Nos. 1 and 2 (Conn). 



Source and habitat — Milk. 



Morphology — 7 to i-i /x in diameter; 

 grouped in pairs by dividing in two 

 directions. 



Staining reaction — Ordinary aniline 

 stains. 



Biology : cultural characters {includ- 

 ing biochemical features). 



Bouillon — Becomes cloudy. 



Gelatine plates and tubes — No. 

 I, granular colonies with folded 

 edges ; slowly liquefying, particu- 

 larly in stab-cultures. No. 2, white 

 opaque colonies ; slowly liquefying. 



Potato — No. I, a dry snow-white 

 opaque growth. No. 2, growth 

 hardly visible. 



Milk — No. I, curdles at 36° C. 

 in 5 days ; hard curd ; acid reac- 

 tion, sour smell. No. 2, renders 



