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MANUAL OF DETERMINATIVE BACTERIOLOGY 



his nigcr Migula, Syst. der Bakt., 2, 

 1900, 636.) From Latin niger, black. 



The black pigment characterizing this 

 organism is formed only in media contain- 

 ing tyrosine (Clark and Smith, Jour. 

 Bact., 37, 1939, 279). The ability to 

 form the pigment may be lost through 

 serial transfer and colony selection. It 

 then cannot be separated from Bacillus 

 subtilis (Gordon and Smith, loc. cit.). 



Source: First isolated from milk. 



Habitat: Widely distributed in soil. 



2. Bacillus pumilus Gottheil. (Cent. 

 f. Bakt., II Abt., 7, 1901, 681.) From 

 Latin pumilus, dwarfish, little. 



Synonyms : Bacillus mesentericus as 

 interpreted by Chester, Del. Agric. Exp. 

 Station, 15th Ann. Report, 1903, 87; 

 Bacillus mesentericus as given by Law- 

 renceand Ford, Jour. Bact., 1, 1916, 295 

 and 300; Bacillus mesentericus va,r.flavus 

 Laubach, Jour. Bact., 1, 1916, 497; per- 

 haps also Bacillus parvus Neide, Cent. f. 

 Bakt., II Abt., 12, 1904, 344; Bacillus 

 leptodermis Burchard, Arb. a. d. bakt. 

 Inst. d. techn. Hochschule zu Karlsruhe, 

 2, 1898, 33. 



Spores: Ellipsoidal to cylindrical, thin 

 walled, naked, central or paracentral, 

 usually about 0.5 by 1.0 micron although 

 some may approach the size of those of 

 Bacillus subtilis. 



Sporangia: Ellipsoidal to cylindrical, 

 not bulged. 



Rods : 0.6 to 0.7 by 2.0 to 3.0 microns, 

 usually occurring singly or in pairs. 

 Chains, filaments and shadow forms may 

 be found in some strains . Cells grown on 

 glucose nutrient agar have few small fat 

 globules. Motile with peritrichous fla- 

 gella. Gram-positive. 



Gelatin stab: Slow liquefaction. 



Agar colonies: Thin, flat, spreading, 

 dendroid, smooth, translucent. The 

 rough stage also occurs. 



Agar slants : Growth moderate, smooth, 

 soft, thin, glistening, non-adherent, 

 spreading, usually whitish although it 

 may be yellowish. The rough stage is 



tough and finely wrinkled, sometimes re- 

 sembling certain strains of Bacillus 

 subtilis. 



Broth: Lrniform turbidity, with or 

 without a ring or half-formed pellicle. 

 The rough stage forms a pellicle. 



Milk : Peptonized, sometimes coagu- 

 lated. 



Milk agar plate: Casein hydrolyzed. 



Potato : Growth is smooth, thin, spread- 

 ing, moist to slimy, yellowish, turning 

 somewhat brown. The rough stage is 

 dry and finely wrinkled. 



Nitrites not produced from nitrates. 



Starch not hydrolyzed. 



Acid with ammoniacal nitrogen from 

 arabinose, xylose, glucose, fructose, galac- 

 tose, mannose, sucrose, salicin, glycerol 

 and mannitol ; usually also from maltose 

 and raffinose. Reaction variable with 

 dextrin. Usually no acid from rhamnose, 

 lactose, and inulin. 



Acetylmethylcarbinol produced. 



Citrates utilized as sole source of 

 carbon. 



Optimum temperature about 30°C. 

 Maximum temperature allowing growth 

 usually about 50°C. 



Aerobic . 



Source: Isolated from plants, cheese, 

 dust, and as a contaminant of media. 



Habitat : Widely distributed in nature. 



3. Bacillus coagulans Hammer. (Iowa 

 Agric. Exp. Station, Research Bull. 19, 

 1915, 129 ; Sarles and Hammer, Jour. 

 Bact., 23, 1932, 301.) From Latin 

 coagulans, curdling, coagulating. 



Synonyms: Bacillus thermoacidurans 

 Berry, Jour. Bact., 25, 1933, 72; Bacillus 

 dextrolacticus Andersen and Werkman, 

 Iowa State Coll. Jour, of Sci., 14, 1940, 

 187. 



Spores: Ellipsoidal to cylindrical, ter- 

 minal or subterminal, thin walled, 0.6 

 to 0.9 by 1.0 to 1.5 microns. Sporulation 

 better on acid proteose peptone agar 

 (Stern, Hegarty, and Williams, Food 

 Research, 7, 1942, 186). 



