248 



ORDER I. PSEUDOMONADALES 



0.8 by 2.0 to 8.0 microns, occurring singly, 

 in pairs or in short chains. Active, darting 

 motility by means of 1 to 3 polar flagella. 

 Gram-negative. 



Grows only in media to which body fluids 

 (blood, ascites, etc.) have been added or in 

 other enriched media. 



Ascitic fluid broth: Almost imperceptible 

 turbidity. 



Thioglycollate broth: Light, floccular 

 turbidity. 



Blood agar colonies : After 5 days, smooth, 

 convex, grayish yellow, dull and translucent 

 with a finely fimbriate margin. Less than 

 0.5 mm in diameter. Frequently surrounded 

 by a narrow zone of green. 



Coagulated blood serum: Cloth-like 

 growth. No odor. 



Genus II. Desulfovibrio Kluyver and van Niel, 1936.* 



(Kluyver and van Niel, Zent. f. Bakt., II Abt., H, 1936, 369; Sporovibrio 

 Starkey, Arch. f. Mikrobiol., 9, 1938, 300.) 



De.sul.fo.vib'ri.o. L. pref. de from; L. sulfur sulfur; L. v. vibro to vibrate; M.L. mas.n. 

 Vibrio that which vibrates, a generic name; M.L. mas.n. Desulfovibrio a vibrio that reduces 

 sulfur compounds. 



Slightly curved rods of variable length, usually occurring singly but sometimes in short 

 chains which have the appearance of spirilla. Swollen pleomorphic forms are common. 

 Actively motile by means of a single polar flagellum. Strict anaerobes which reduce sulfates 

 to hydrogen sulfide. Found in sea water, marine mud, fresh water and soil. 



The type species is Desulfovibrio desulfuricans (Beijerinck) Klu3^ver and van Niel. 



Nitrites produced from nitrates by some 

 strains. 



Indole not produced. 



Hydrogen sulfide produced. 



Carbohydrates not utilized. 



Optimum pH, 7.2. Feeble growth between 

 pH 6.0 and 9.7. 



Serology: Cross-reacting, somatic anti- 

 gens have been demonstrated. 



Anaerobic. 



Optimum temperature, 37° C. Growth 

 feeble at 27° and 45° C. No growth at 20° C. 



Source: Isolated by Pr^vot from a case of 

 bronchitis. 



Habitat: Found in the human oral cavity 

 and in fusospirochetal diseases of the mouth. 



1. Desulfovibrio desulfuricans (Beijer- 

 inck, 1895) Kluyver and van Niel, 1936. 

 (Bacterium hydrosulfureum ponticum Zelin- 

 sky, Proc. Russ. Phys. and Chem. Soc, 25, 

 1893, 298; Spirillum desulfuricans Beijer- 

 inck, Cent. f. Bakt., II Abt., 1, 1895, 1; 

 Kluyver and van Niel, Zent. f. Bakt., II 

 Abt., 94, 1936, 369; Sporovibrio desulfuricans 

 Starkey, Koninkl. Nederland. Akad. v. 

 Wetenschappen, Proc, 41, 1938, 426; also in 

 Arch. f. Mikrobiol., 9, 1938, 268.) 



de.sul.fur'i.cans. L. pref. de from; L. 

 noun sulfur sulfur; M.L. part. adj. desul- 

 furicans reducing sulfur compounds. 



Slightly curved rods, 0.5 to 1.0 by 1 to 5 

 microns, usuall}- occurring singly but some- 

 times in pairs and short chains which cause 

 them to look like spirilla. Swollen pleomor- 



phic forms are common. Older cells appear 

 black due to precipitated ferric sulfide. 

 Actively motile, possessing a polar flagel- 

 lum. Stains readily with carbol fuchsin. 

 Gram-negative. 



Gelatin: No liquefaction. 



Grows best in fresh-water media. Fails to 

 develop in sea water upon initial isolation. 



Produces opalescent turbidity in absence 

 of oxygen in mineral media enriched with 

 sulfate and peptone. 



Media containing iron salts and sulfur 

 compounds blackened. Bacteria found asso- 

 ciated with precipitated ferrous sulfide. 



Peptone-glucose agar colonies (in absence 

 of air) : Small, circular, slightly raised, dull, 

 entire, soft in consistency. 



Peptone, asparagine, glycine, alanine, 



* Prepared by Dr. Claude E. ZoBell, Scripps Institution of Oceanography, La Jolla, Cali- 

 fornia, January, 1943; revised January, 1953. 



