374 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



Yeast gelatin-lactate stab : No lique- 

 faction. 



Yeast agar-lactate stab : Dirty grayish- 

 creanay development in stab ; very slight 

 surface growth of same color. 



Liquid media : Distinctly turbid with 

 grayish-creamy, ropy sediment. 



Litmus milk: Acid coagulation. 



Catalase positive. 



Indole not formed. 



Nitrites not produced from nitrates. 



Ferments lactic and pyruvic acids, 

 glycerol, dihydroxyacetone, glucose, fruc- 

 tose, mannose, galactose and lactose with 

 the formation chiefly of propionic and 

 acetic acids, and carbon dioxide. Occa- 

 sional!}^ arabinose is fermented. 



Acid from erythritol, adonitol, arabi- 

 tol, inositol and esculin. No acid from 

 amygdalin, dextrin, dulcitol, glycogen, 

 inulin, maltose, mannitol, melezitose, 

 melibiose, perseitol, raffinose, rhamnose, 

 salicin, sorbitol, sucrose, starch, tre- 

 halose or xylose. 



Anaerobic. 



Distinctive characters : Resembles Pro- 

 pionibacterium freudenreichii in every 

 respect, but differs in its abilitj' to 

 ferment lactose. 



Source : From dairy products ; Swiss 

 cheese and buttermilk. 



Habitat: Dairy products. 



3. Propionibacterium rubrum van 

 Niel. (Bacterium acidi propionici var. 

 rubrum Thoni and AUemann (in part), 

 Cent. f. Bakt., II Abt., 25, 1910, S; van 

 Niel, The Propionic Acid Bacteria, 1928, 

 164; Werkman and Brown, Jour. Bact., 

 26, 1933, 414.) From Latin ruber, red. 



Medium-sized, stoutish rods to 

 elongated diplococci, 0.8 by 1.2 microns, 

 occurring singly or in pairs, resembling 

 diphtheroids rather than streptococci. 

 Somewhat more slender in media without 

 fermentable carbohydrate. Aerobic 

 growth irregular, club-shaped and 

 branched rods. Non-motile. Show 

 metachromatic granules. Gram-posi- 

 tive. 



Yeast gelatin-lactate stab : No lique- 

 faction. 



Yeast agar-lactate stab : Brownish-red 

 development in stab, with appreciable 

 dome-shaped surface growth of same 

 color. (Also see Margolena and Hansen, 

 Cent. f. Bakt., II Abt., 99, 1938, 107.) 



Liquid media: Turbidity in early 

 stages, sediment red and smooth. 



Litmus milk: Acid coagulation. 



Catalase positive ; very weak for aerobi- 

 cally grown cells. 



Indole not formed. 



Nitrites not produced from nitrates. 



Ferments lactic and pyruvic acids, 

 glycerol, dihydroxyacetone, glucose, fruc- 

 tose, mannose, galactose, sucrose, malt- 

 ose, lactose, raffinose and mannitol with 

 the production chiefly of propionic and 

 acetic acids and carbon dioxide. 



Acid from erythritol, adonitol, arabitol, 

 amygdalin, esculin, salicin, melezitose 

 and trehalose. No acid from d- and 1- 

 arabinose, dextrin, dulcitol, glycogen, 

 inulin, melibiose, perseitol, rhamnose, 

 sorbitol, starch or xylose. 



Less anaerobic than Propionibacterium 

 freudenreichii and Propionibacterium 

 shermanii. 



Distinctive characters : Production of 

 brownish-red pigment under anaerobic 

 and aerobic conditions. Fermentation 

 of raffinose and mannitol, not of sorbitol. 



Source: From various dairy products. 



Habitat: Dairy products. 



4. Propionibacterium thoenii van Niel. 



{Bacterium acidi propionici var. rubrum 

 Thoni and Allemann (in part). Cent. f. 

 Bakt., II Abt., 25, 1910, 8; van Niel, 

 The Propionic Acid Bacteria, 1928, 164; 

 Werkman and Brown, Jour. Bact., 26, 

 1933, 412.) Named for Thoni, the Swed- 

 ish bacteriologist, who isolated this 

 organism. 



Description taken from van Niel, and 

 Werkman and Brown. 



Medium sized, stoutish rods to 

 elongated diplococci, 1.0 by 1.5 microns, 

 occurring singly or in pairs, resembling 



