576 



ORDER IV. EUBACTERIALES 



M.L. neut.n. arabinosum arabinose, a pen- 

 tose sugar derived from gum arable. 



Cells in neutral lactate media spherical, 

 0.8 micron in diameter, occurring in pairs 

 and short chains. In acid media swollen 

 spheres and ellipsoidal cells occur, mostly 

 2.0 by 3.0 to 3.5 microns, often in pairs and 

 short chains. Non-motile. Show metachro- 

 matic granules. Gram-positive. 



Yeast-gelatin-lactate-stab: No liquefac- 

 tion. 



Yeast-agar-lactate-stab : Cream-colored 

 growth in stab with distinct orange-yellow 

 surface growth. 



Liquid cultures: Turbid in early stages; 

 cream-colored, smooth sediment. 



Litmus milk: No coagulation. 



Indole not produced. 



Ferments lactic and pyruvic acids, glyc- 

 erol, dihydroxyacetone, d- and 1-arabinose, 

 glucose, galactose, fructose, mannose, cello- 

 biose, maltose, sucrose, raffinose and man- 

 nitol with the production of propionic and 

 acetic acids and carbon dioxide. 



Acid from sorbitol. No acid from dulcitol, 

 xylose, rhamnose, salicin or inulin. 



Pantothenic acid and biotin, but not 

 para-aminobenzoic acid, are required for 

 growth; thiamine, although not required, 

 is growth-stimulating (Delwiche, Jour. 

 Bact., 58, 1949, 396). 



Nitrite production not recorded. 



Very slightly catalase-positive. 



Anaerobic, but less so than Propionibac- 

 terium freudenreichii. 



Distinctive characters: The development 

 of spherical involution forms in acid media, 

 the almost complete absence of catalase 

 and the ability to ferment both d- and 

 1-arabinose but not xylose or rhamnose. 



Note : The strain obtained from Dr. E. B. 

 Fred produced only minute amounts of acid 

 from lactose and starch; it is questionable 

 whether these carbohydrates are fermented. 



Source: Not definitely stated. 



Habitat: Dairy products. 



11. Propionibacterium pentosaceum 



van Niel, 1928. {Bacillus acidi propioriici 

 von Freudenreich and Orla- Jensen, Cent. f. 

 Bakt., II Abt., 17, 1906, 532; van Niel, The 

 Propionic Acid Bacteria, Haarlem, 1928, 

 163.) 



pen.to.sa'ce.um. Gr. pi. adj. pente five; 

 M.L. neut.n. pentosum a pentose sugar; 

 M.L. adj. pentosaceus relating to a pentose. 



Description taken from van Niel {loc. 

 cit.) and from Werkman and Brown (Jour. 

 Bact., 26, 1933, 408). 



In neutral lactate media cells spherical, 

 0.8 micron in diameter, occurring in pairs 

 and short chains. In media developing acid- 

 ity, long, irregular rods, swollen and 

 branched, 3 to 4 microns in length, occur. 

 Aerobic growth occurs as irregular, swollen 

 and branched, long rods. Non-motile. Show 

 metachromatic granules. Gram-positive. 



Yeast-gelatin-lactate stab: No liquefac- 

 tion. 



Yeast-agar-lactate stab: Cream-colored 

 development in stab with abundant, cream- 

 colored surface growth. 



Liquid media: Turbid in early stages; 

 smooth, creamy sediment; ropy. 



Litmus milk: Coagulated, acid. 



Indole not produced. 



Ferments lactic and pyruvic acids, glyc- 

 erol, dihydroxyacetone, d- and 1-arabinose, 

 xylose, rhamnose, glucose, galactose, fruc- 

 tose, mannose, cellobiose, lactose, maltose, 

 sucrose, raffinose, mannitol and sorbitol 

 with the production of propionic and acetic 

 acids and carbon dioxide. 



Acid from adonitol, arabitol, erythritol, 

 esculin, inositol, salicin and trehalose. No 

 acid from dextrin, dulcitol, glycogen, inulin, 

 perseitol or pectin. 



Pantothenic acid and biotin, but not 

 para-aminobenzoic acid, are growth re- 

 quirements; although thiamine is not re- 

 quired, it is stimulating for growth (Del- 

 wiche, Jour. Bact., 58, 1949, 396). 



Nitrites and free nitrogen produced from 

 nitrates. 



Slightly catalase-positive. 



Anaerobic, but less so than any of the 

 other species of the genus. 



Distinctive characters: The formation of 

 long, rod-shaped involution forms in acid 

 media, the absence of pigment production, 

 and the ability to ferment d- and 1-arabi- 

 nose, rhamnose and xylose. 



Source: Isolated from Emmental cheese. 



Habitat: Dairy products. 



