FAMILY BACILLACEAE 



719 



cal in all respects with Bacillus cereus 

 except in the following characters : 



Agar colonies : Grayish, thin, widely 

 spreading by means of long twisted chains 

 of cells, turning to the right or left. 



Agar slants : Growth thin, rhizoid, 

 grayish, widely spreading, adhering to or 

 growing into the agar. Later, growth 

 becomes thicker and softer. 



The physiological similarity between 

 Bacillus cereus and Bacillus mycoides 

 has often been noted. Gordon (Jour. 

 Bact., 39, 1940, 98) showed that the 

 rhizoid character of the growth of Bacil- 

 lus mycoides was readily lost by cultiva- 

 tion in flasks containing 100 ml of broth 

 and that the resulting dissociants could 

 not be differentiated from Bacillus cereus. 

 It is, therefore, a question whether Ba- 

 cillus mycoides should be given the dig- 

 nity of a variety of Bacillus cereus or 

 merely designated as a stage of growth 

 (morphotype). 



Source : Isolated from soil. 



Habitat: Widely distributed in soil. 



8. Bacillus anthracis Cohn emend. 

 Koch. (Les infusories de la maladie 

 charbonneuse, Davaine, Compt. rend. 

 Acad. Sci., Paris, 69, 1864, 393; Cohn, 

 Beitrage z. Biol. d. Pflanzen, 1, Heft 2, 

 1872, 177; Koch, ibid., 2, Heft 2, 1876, 

 279; Bacteridie des charbon, Pasteur and 

 Joubert, Compt. rend. Acad. Sci., Paris, 

 S4, 1877, 900; Bacterium anthracis Zopf, 

 Die Spaltpilze, 2 Aufl., 1884, 45; Bacillus 

 {Streptohacter) anthracis Schroeter, 

 Kryptogamen Flora v. Schlesien, 3, 1, 

 1886, 163; Pollendera anthracis Trevisan, 

 1884, see Trevisan, I generi e le specie 

 delle Batteriacee, 1889, 13; Bacterium 

 anthracis Migula, in Engler and Prantl, 

 Die natiirlichen Pflanzenfam., 1, la, 

 1895, 21; Aplanobacter anthracis Erw. 

 Smith, Bacteria in Relation to Plant 

 Diseases, 1905, 171; Bacillus {Bacteri- 

 dium) anthracis Buchanan, Jour. Bact., 

 3, 1918, 37.) From Greek, gen. of an- 

 thrax, charcoal, a carbuncle, the disease 

 anthrax. 



According to Smith, Gordon, and Clark 

 {loc. cit.) this species is a pathogenic 

 variety of Bacillus cereus. They worked 

 extensively with the latter but not with 

 many strains of Bacillus anthracis. The 

 only difference between the two seemed 

 to be pathogenicity and motility, and 

 some strains of Bacillus cereus are weakly 

 pathogenic and some practically non- 

 motile. It would appear that Bacilhis 

 cereus is a so-called parent species from 

 which two varieties (var. anthracis and 

 var. mycoides) and several morpho- and 

 biotypes have sprung. 



Spores : Ellipsoidal, 0.8 to 1.0 by 1.3 to 

 1.5 microns, central or paracentral, often 

 in chains. Germination polar. 



Sporangia: Ellipsoidal to cylindrical, 

 not swollen, in chains. 



Rods : 1.0 to 1.3 by 3 to 10 microns with 

 square or concave ends, occurring in long 

 chains, resemble Bacillus cereus. Cells 

 from glucose or glycerol nutrient agar 

 appear granular (vacuolated) if stained 

 lightly ; many fat globules present. Non- 

 motile. Gram-positive. 



Gelatin stab : Arborescent in depth, 

 inverted pine tree. Liquefaction cra- 

 teriform becoming stratiform. 



Agar colonies : Large, irregular, dense, 

 curled structure composed of parallel 

 chains, similar to certain strains of 

 Bacillus cereus. 



Agar slant : Growth abundant, grayish, 

 dense, spreading, with fimbriate borders. 



Broth : Little or no turbidity, thick 

 pellicle. 



Milk: Coagulated, slightly acid, pep- 

 tonized. 



Potato : Growth abundant, spreading, 

 white to creamy. 



Nitrites formed from nitrates. 



Starch is hydrolyzed. 



Acid from glucose, fructose, sucrose, 

 maltose, trehalose, and dextrin. Some 

 strains produce late and slight acidity in 

 glycerol and salicin. No definite fer- 

 mentation occurs in arabinose, rhamnose, 

 mannose, galactose, lactose, raffinose, 

 inulin, mannitol, dulcitol, sorbitol, inosi- 



