FAMILY BACILLACEAE 



13 



Sporangia: Only slightly swollen, if at 

 all. 



Rods: 0.5 to 0.9 by 2.5 to 3 microns, 

 singly or in short chains, resemble Ba- 

 cillus suhtilis. Cells from glucose agar 

 contain few small fat globules. Motile. 

 Gram-positive. 



Gelatin: No growth at 20°C. Xo 

 change in gelatin by Frazier method at 

 45°C. 



Agar colonies : Small, entire, raised, not 

 characteristic. 



Agar slants : Growth scant to moderate, 

 thin, flat. On acid proteose peptone agar 

 growth is more abundant and micro- 

 scopically the cells appear healthier. 



Broth: Moderate uniform turbidity, 

 followed by clearing. Glucose broth 

 attains a pH of 4.0 to 4.4. 



Milk: Coagulated. 



Milk agar plate: Weak hjdrolysis of 

 casein. 



Potato: Growth scant to moderate, 

 thin, spreading, white to cream-colored. 

 May have a sour odor. 



Nitrites usually not formed from 

 nitrates. 



Starch is hydrolyzed. 



Acid from glucose, galactose, fructose, 

 lactose, maltose, sucrose, dextrin, and 

 glycerol. Usually no acid from arabinose 

 and sorbitol. No acid from xylose and 

 mannitol. Organic nitrogen preferable 

 to inorganic. 



Acetylmethylcarbinol produced. 



Citrates not used as sole source of 

 carbon. 



Optimum temperature about 45°C 

 (Hammer, 55°C). Maximum tempera- 

 ture allowing growth 54°C to 60°C. Slow 

 growth, if any, at 25°C. 



Aerobic, facultative. 



Source: Isolated from evaporated milk 

 (Hammer) and tomato juice (Berry). 



Habitat : Canned goods ; probably 

 widelv distributed in nature. 



Spores: Usually ellipsoidal, central to 

 subterminal, 0.6 to 0.7 by 1.0 to 1.2 

 microns on Ca-n-butyrate agar (Wer- 

 ner) ; 0.7 to 0.9 by 1.0 to 1.4 microns on 

 nutrient agar. Sporulation better on 

 plain peptone agar than on nutrient agar. 



Sporangia: Ellipsoidal to cylindrical, 

 sometimes slightly bulged. 



Rods : 0.6 to 0.9 by 1.5 to 4.0 microns, 

 single or in short chains, few filaments. 

 On glucose nutrient agar there are swol- 

 len, shadow, and other abnormal forms, 

 few small fat globules. Motile with 

 peritrichous flagella. Gram-positive. 



Gelatin stab : Slow liquefaction. Gela- 

 tin plate shows wide zone of hydrolysis. 



Agar colonies: Small, smooth, dense, 

 entire, white to pink. 



Agar slants : Growth moderate, smooth, 

 opaque, not spreading, whitish. Pink 

 variations may occur. Growth inhibited 

 when glucose is added, because of the 

 production of acid. No growth at pH 

 6.0 or below. 



Broth: Scant uniform turbiditj' or a 

 flocculent growth. 



Milk agar plate : Weak to strong casein 

 hydrolysis. 



Potato: No growth. 



Nitrites produced from nitrates. 



Starch is hydroh'zed. 



Acid from glucose. No acid from 

 arabinose and xylose. Ammonium salts 

 not used as sole source of nitrogen. 



Acetylmethylcarbinol not produced. 



Citrates usually not utilized. 



Urease not produced. 



Salt tolerance: Will grow in nutrient 

 broth containing 4 to 7 per cent NaCl. 



Optimum temperature about 28°C. 

 Maximum temperature allowing growth 

 37°C to 45°C. 



Source: Seven strains isolated from 

 soils in Central Europe and Egypt. 



Habitat: Widely distributed in soil. 



4. Bacillus firmus Werner. (Cent. f. 

 Bakt., II Abt., 87, 1932, 470.) From 

 Latin firmus, firm, strong. 



5. Bacillus lentus Gibson. (Cent. f. 

 Bakt., II Abt., 92, 1935, 368.) From 

 Latin lentus, slow. 



