74 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



pseudo-tissue of interwoven filaments 

 suggestive of a fungus pad. The pad can 

 be removed as a unit from the medium. 

 • Aerobic. 



Source: Activated sludge. 



Habitat: Unknown. 



3. Nitrosogloea membranacea H. 



Winogradskjr. (Nitrosocystis "HI", H. 

 Winogradsky, Trans. Third Intern. Cong. 

 Soil Sci., Oxford, 1, 1935, 139; Compt. 

 rend. Acad. Sci., Paris, 200, 1935, 1887; 

 Ann. Inst. Pasteur, 58, 1937, 333.) From 



Latin, membranaceus , of skin or 

 membrane. 



Ellipsoidal cells conamonly in pairs and 

 also solitary. 



Colonies on silica gel : Appear as dull 

 mucoid material with a pale straw color. 

 The cells are held firmly together so that 

 the entire colony is easily picked up with 

 the transfer needle. No structural units 

 within the colony. 



Aerobic. 



Source: Activated sludge. 



Habitat: Unknown. 



Genus VI. Nitrobacter Winogradsky. 



(Winogradsky, Arch. Sci. biol., St. Petersburg, /, 1892, 127; Nitromonas Orla- 

 Jensen, Cent. f. Bakt., II Abt., 22, 1909, 334; not Nitromonas Winogradsky, Ann. 

 Inst. Past., 4, 1890, 257; Nitrohacterium Castellani and Chalmers, Manual Trop. Med., 

 1919, 933.) 



Cells rod-shaped. Oxidize nitrite to nitrate. From Latin, nitrum, soda; M.L. 

 nitre; and Greek baktron, a small rod. 

 The type species is Nitrobacter winogradskyi Buchanan. 



1. Nitrobacter winogradskyi Buch- 

 anan. {Nitrobacter Winogradsky, Arch. 

 Sci. biol., St. Petersburg, 1, 1892, 127; 

 Bacterium nitrobacter Lehmann and Neu- 

 mann, Bakt. Diag., 2nd ed., 2, 1899, 187; 

 Bacillus nitrobacter Lohnis, Vorlesungen 

 landw. Bakt., Berlin, 1913, 152; Buch- 

 anan, Jour. Bact., 3, 1918, 180; Nitrobac- 

 terium nitrobacter Castellani and Chal- 

 mers, Manual Trop. Med., 1919, 933.) 

 Named for S. Winogradsky, 1856- , the 

 Russian microbiologist, who first isolated 

 these bacteria. 



Description taken from Gibbs, Soil 

 Sci., 8, 1919, 448. 



Short, non-motile rods with gelatinous 

 membrane, 0.6 to 0.8 by 1.0 to 1.2 mi- 

 crons. Does not stain readily. Gram- 

 negative (Omelianski, Cent. f. Bakt., II 

 Abt., 19, 1907, 263.) 



Can be cultivated on media free of 

 organic matter. Sensitive to certain 

 organic compounds. 



Washed agar colonies : In 7 to 10 days 

 very small, light brown, circular to ir- 

 regular colonies, becoming darker. 



Silica gel : Colonies smaller but more 

 dense than on washed agar. 



Washed agar slant: In 7 to 10 days 

 scanty, grayish streak. 



Inorganic solution medium: After 10 

 days flocculent sediment. Sensitive to 

 ammonium salts under alkaline condi- 

 tions. 



Nitrite is oxidized to nitrate. 



Aerobic. 



Strictly autotrophic. 



Optimum temperature 25° to 28°C. 



Source: Soil. 



Habitat: Presumably widely distrib- 

 uted in soil. 



2. Nitrobacter agile Nelson. (Cent, f . 

 Bakt., II Abt., 83, 1931, 287.) From 

 Latin agile, quick, agile, motile. 



Rods: 0.5 by 0.8 to 0.9 micron, occur- 

 ring singly, sometimes in pairs or larger 

 aggregates. Rapidly motile with a long, 

 thin, polar flagellum often 7 to 10 times 

 as long as the rod. (Non-motile culture 

 obtained by Ivingma Boltjes, Arch. f. 

 Mikrobiol., 6, 1935, 79.) Gram -negative. 



