FAMILY XI. PROPIONIBACTERIACEAE 



573 



480) reports that this species may or may 

 not ferment lactose and may or may not 

 produce acid from esculin and salicin. 



Pantothenic acid and biotin, but not 

 para-aminobenzoic acid, are growth re- 

 quirements; thiamine is required by some 

 strains, but other strains, while not requir- 

 ing this vitamin, find it stimulating for 

 growth (Delwiche, Jour. Bact., 58, 1949, 

 396). 



Nitrites not produced from nitrates. 



Catalase-positive. 



Less anaerobic than Propionibacteriiun 

 Jreudenreichii and Propionihacterium sher- 

 nianii. 



Distinctive characters : Closely resembles 

 Propionihacterium rubrum in morphology 

 and in the production of brownish red pig- 

 ment under aerobic and anaerobic condi- 

 tions. Differs from this species in its inabil- 

 ity to ferment rafiinose and mannitol, 

 whereas fermentation of sorbitol occurs. 



The biochemical characteristics of a ten- 

 year-old stock culture have remained un- 

 changed. 



Source: Isolated from cheese and butter- 

 milk. 



Habitat: Dairy products. 



5. Propionibacterium zeae Hitchner, 



1932. (Jour. Bact., £S, 1932, 40; also see 

 ibid., 28, 1934, 473.) 



ze'ae. Gr. fem.n. zia spelt; M.L. fem.n. 

 Zea generic name of maize; M.L. gen.noun 

 zeae of maize. 



Cells in neutral lactate media spherical, 

 0.8 micron in diameter, usually occurring 

 in short chains. In carbohydrate media 

 which turn acid during development, the 

 cells are distinctly rod-shaped, 0.8 by 2.0 

 to 3.0 microns, with a slight tendency to- 

 wards the formation of club-shaped forms. 

 Appearance typically diphtheroid. Aerobic 

 growth occurs as irregular, club-shaped and 

 branched rods. Non-motile. Show meta- 

 chromatic granules. Gram-positive. 



Yeast-gelatin-lactate-stab: I^o liquefac- 

 tion. 



Yeast-agar-lactate-stab : Cream-colored 

 growth in stab with distinct surface growth 

 of same color. 



Liquid media: Distinctly turbid; cream- 

 colored; smooth sediment; very ropy. 



Litmus milk: Coagulated; acid. 



Indole not produced. 



Ferments lactic and pyruvic acids, glyc- 

 erol, dihydroxyacetone, 1-arabinose, rham- 

 nose, glucose, fructose, mannose, galactose, 

 sucrose, cellobiose, maltose, lactose and 

 mannitol with the production of propionic 

 and acetic acids and carbon dioxide. 



Acid from salicin. No acid from d-arabi- 

 nose, dextrin, dulcitol, glycogen, inulin, 

 starch or xylose. 



Pantothenic acid and biotin are required 

 for growth; thiamine and para-aminoben- 

 zoic acid, although not required, are growth- 

 stimulating (Delwiche, Jour. Bact., 58, 

 1949, 396). 



Nitrites not produced from nitrates. 



Catalase-positive, especially when grown 

 in neutral media. 



Less anaerobic than Propionibacterium 

 freudenreichii and Propionibacterium sher- 

 manii. 



Distinctive characters: Cream-colored 

 surface growth and ability to ferment 

 1-arabinose and rhamnose but not d-arabi- 

 nose or xylose. 



Source: Not definitely recorded, but prob- 

 ably isolated from silage. 



Habitat: Dairy products. 



6. Propionibacterium technicuni van 



Niel, 1928. (The Propionic Acid Bacteria, 

 Haarlem, 1928, 164.) 



tech'ni.cum. Gr. adj. technicus technical. 



In neutral media spherical cells, 0.8 mi- 

 cron in diameter, occur in pairs and in short 

 chains. In acid media short rods, 0.6 by 1.0 

 to 1.5 microns, occur, often in pairs, with a 

 typical diphtheroid appearance. Aerobic 

 growth occurs in the form of irregular, long 

 rods, swollen and branched. Non-motile. 

 Show metachromatic granules. Gram-posi- 

 tive. 



Yeast-gelatin-lactate-stab: No liquefac- 

 tion. 



Yeast-agar-lactate-stab : Cream-colored 

 development in stab with distinct yellow 

 surface growth. 



Liquid media: Turbid in early stages; 

 cream-colored, somewhat flocculent sedi- 

 ment. 



Litmus milk: Coagulation, acid. 



Indole not produced. 



