CLOSTRIDIUM BUTT RIG UM 873 



of growth between 50° and 60° C, associated with the tyj^e of spoilage of non- 

 acid canned foods known in the United States as " hard swell " (see also Paine 

 1931, McCoy 1937). In addition to the common proteolytic Clostridia of the 

 CI. sporogenes type associated with food spoilage, we may note an organism resem- 

 bling CI. ivelchii (McClung and Wheaton 1936), and an organism resembling CI. 

 oedematiens- which Haines and Scott (1940) found associated with " bone taint " 

 of cattle carcases. (For practical keys to the separation of the Clostridia see 

 Spray 1936, Keed and Orr 1941). 



Clostridium butyricum 



Synonyms. — Clos. pasteurianum, B. amylobacter, Oranulobacier saccharohutyricum. Pasteur's 

 Vibrion butyrique. 



Isolation.— ApY^arently first described by Prazmowski (see Report 1919). Possibly iden- 

 tical with Pasteur's Vibrion butyrique, described fully by Winogradsky in 1902 



Habitat. — Soil. 



Morphology. — Rods, 3-4// X 1 /u. ; parallel sides, flattened ends, axis straight or slightly 

 curved ; arranged singly or in pairs end-to-end ; considerable variation in 

 length. Motile by peritri- 



chate flagella. Spores oval, ~ ^ ^ 



subterminal, measuring \% n 

 X 1 -3 // ; rod becomes spindle- 

 shaped. Germination polar. 



Capsule formed on agar. Cells f ^ ^ 



store glycogen ; stain yellow . \ m 



with iodine. Gram-positive. **>*"* V h M A^ •» **V^ 



Agar Plate.— 2 days, m° C. Circular "^^^ ~i' *%^.^ ^ ^ 



colonies, 0-5-1 mm. in dia- ^ •** ^\ ** "< ^ ^ >) 



meter, low convex, amorphous, «^ ^ ^^^ ^ /t* 



faintly translucent or opaque, -^^ ^ 



greyish-white, with smooth ^'^% '^ >, . 



glistening surface and entire "^ /^ ^ i^ .«» ^ * 



edge ; butyrous consistency and v \ I 



easily emulsifiable. After 6 — J 



days the colonies are slightly 



larger. ^.^ ^ 



Agar Stroke. — 4 days at 30° C. Very "^ 



poor growth of discrete, irregu- ^^^ 192. -Closlridium butyricum. 



lar colonies, slightly raised, and „ , ,, • • n -- j 



, Jr^ J* rom a surface agar culture, anaerobically, 5 days, 



water-clear. On 0-5 per cent. 37°C. (x loOO). 



mannitol agar there is a moder- 

 ate, raised, greyish-white, opaque growth, consisting chiefly of discrete colonies 



with a moist, glistening, smooth surface. 

 Gelatin Stab. — No growth. 

 Glncose Agar Shake. — 2 days at 30° C. Good growth ; the medium is disrupted by large 



bubbles of gas, and blown up the tube. Colonies are yellowish-grey, opaque, 



biconvex with clear-cut edges, and about 1 mm. in diameter. 

 Broth. — 2 days at 30° C. Poor to moderate growth, with slight turbidity, and slight, 



very finely granular deposit ; after 6 days, moderate turbidity, and moderate 



powdery deposit, disintegrating completely on shaking. 

 Loeffler's Blood Serum. — 2 days at 30" C. Moderate, raised, confluent, colourless growth 



with irregularly contoured surface. No digestion. 

 Cooked Meat Medium.— 5 days, 37° C. Marked turbidity ; no digestion. 



