116 



ORDER I. PSEUDOMONADALES 



surface colonies look like small, woolly 

 balls. 



Water-insoluble dextrin colonies: Col- 

 onies grow below the surface and have a 

 woolly appearance. Colonies are surrounded 

 by clear zones. Become cream to pale yellow 

 in color. 



Litmus milk : Unchanged except for reduc- 

 tion of litmus at bottom of the tube. 



Indole not produced. 



Nitrites produced from nitrates. 



Starch hydrolyzed. 



Glucose, .xylose, maltose and starch read- 

 ily utilized. Arabinose, galactose and gum 

 arable feebly attacked. No acid formed in 

 any of the above-mentioned substrates. 

 Cellulose, cellulosan, water-soluble and 

 water-insoluble cellulose, dextrins, hemi- 

 cellulose and pectin readily attacked. Filter 

 paper strips become pale yellowish in the 

 area attacked. 



Peptone, yeast extract, nitrate and am- 

 monia are suitable nitrogen sources. 



Aerobic. 



Grows between 22° and 35° C. 



Source: Isolated from soil. 



Habitat: Soil. 



46. Pseudonionas riboflavina Foster, 

 1944. (Pseudotnonas riboflavinus (sic) Foster, 

 Jour.Bact.,47, 1944,27; also see Jour. Bact., 

 48, 1944, 97.) 



ri.bo.fla'vi.na. M.L. adj. riboflavinus 

 pertaining to riboflavin. 



Thin rods of variable length. Motile. 

 Gram-negative. 



Gelatin stab: No liquefaction. 



Yeast-extract agar colonies: Small, con- 

 vex, smooth, transparent; slightly dentate 

 edges. If glucose is added to the agar, 

 copious quantities of polj'saccharides are 

 formed. Presence of fructose, mannitol, su- 

 crose, maltose, lactose, xylose and galactose 

 also lead to polysaccharide formation. 



Yeast-extract glucose broth: Becomes so 

 viscid that it scarcely flows. 



Milk: Soft curd forms. Slowly peptonized. 



Nitrites produced from nitrates. 



No acid or gas from fructose, mannitol, 

 sucrose, maltose, lactose, xylose or galac- 

 tose. Acetic acid oxidized. 



Acetylmethylcarbinol not produced. 



Urea, glycine, ammonium chloride or 



sodium nitrate cannot be used as substi- 

 tutes for organic-nitrogen sources. Neither 

 could 20 water-soluble accessory factors 

 substitute for yeast extract in a synthetic 

 mineral salts-glucose medium. 



No pigment produced in any medium. 



Starch not hydrolyzed. 



Optimum temperature, between 30° and 

 33° C. 



Distinctive characters: In organic media 

 containing a small amount of organic matter 

 such as yeast extract or peptone and 0.05 to 

 0.2 per cent riboflavin, the riboflavin is 

 attacked and converted to lumichrome, 

 which accumulates in the culture as lemon- 

 yellow crystals. If riboflavin is not provided 

 in the medium, appreciable quantities of it 

 are synthesized by this organism. 



Source: Isolated from soil rich in ribo- 

 flavin. 



Habitat: Unknown. 



47. Pseudomonas denitrificans Bergey 

 et al., 1923. (Bacillus denitrificans fluorescens 

 Christensen, Cent. f. Bakt., II Abt., 11, 

 1903, 190; Bergey et al., Manual, 1st ed., 

 1923, 131.) 



de.ni.tri'fi.cans. L. de away, from; L. 

 nitruni soda; M.L. nitrate, niter; M.L. 

 denitrifico to denitrify; M.L. part. adj. 

 denitrificans denitrifying. 



Rods, 0.5 to 0.7 by 0.5 to 1.25 microns, 

 occurring singly and in pairs in large, slimy 

 masses. Motile. Gram-negative. 



Gelatin colonies: Small, circular, con- 

 toured, raised, moist, pearly gray, glisten- 

 ing. 



Gelatin stab: Whitish, lobed surface 

 growth. Yellowish green growth in stab. No 

 liquefaction. 



Agar colonies: Pearly white, circular, 

 entire. 



Agar slant: Broad, whitish, contoured, 

 moist, entire. 



Broth: Turbid, with thick, wrinkled 

 pellicle. 



Litmus milk: Not coagulated. 



Potato: Reddish gray layer. 



Indole not produced. 



Nitrates reduced with production of 

 nitrogen. 



Aerobic, facultative. 



Optimum temperature, 25° C. 



