Page:Bergey's manual of determinative bacteriology.djvu/138

 colonies look like small, woolly balls.

Water-insoluble dextrin colonies: Colonies 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 reduction of litmus at bottom of the tube.

Indole not produced.

Nitrites produced from nitrates.

Starch hydrolyzed.

Glucose, xylose, maltose and starch readily 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, hemicellulose and pectin readily attacked. Filter paper strips become pale yellowish in the area attacked.

Peptone, yeast extract, nitrate and ammonia are suitable nitrogen sources.

Aerobic.

Grows between 22° and 35° C.

Source: Isolated from soil.

Habitat: Soil.

46. Pseudomonas riboflavina Foster, 1944. (Pseudomonas 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, convex, smooth, transparent; slightly dentate edges. If glucose is added to the agar, copious quantities of polysaccharides are formed. Presence of fructose, mannitol, sucrose, 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 galactose. Acetic acid oxidized.

Acetylmethylcarbinol not produced.

Urea, glycine, ammonium chloride or sodium nitrate cannot be used as substitutes 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 riboflavin.

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. nitrum 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, contoured, raised, moist, pearly gray, glistening.

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.