ORDER I. PSEUDOMONADALES 



Source: Activated sludge. 

 Habitat: Unknown. 



Source: Activated sludge. 

 Habitat: Unknown. 



2. Nitrosogloea schizobacteroides H. 



Winogradsky, 1935. (Nitrosocystis "11", H. 

 Winogradsky, Trans. Third Intern. Cong. 

 Soil Sci., Oxford, 1, 1935, 139; H. Winograd- 

 sky, Compt. rend. Acad. Sci., Paris, 200, 

 1935, 1887; Ann. Inst. Past., 58, 1937, 333.) 



schiz.o.bac.te.ro.i'des. Gr. schiza cleft, 

 fission; Gr. noun bactrmn a rod; Gr. noun 

 idus form, shape; M.L. adj. schizobacteroides 

 shaped like a fission rod. 



Elongated rods or short filaments 3 to 4 

 microns long. 



Colonies on silica gel : Flat groups of cells 

 are produced which are united in a common 

 sheath. The aggregates form a pseudo-tissue 

 of interwoven filaments suggestive of a 

 fungus pad. The pad can be removed as a 

 unit from the medium. 



Aerobic. 



3. Nitrosogloea membranacea H. 



Winogradsky, 1935. (Nitrosocystis "III", H. 

 Winogradsky, Trans. Third Intern. Cong. 

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

 Acad. Sci., Paris, 200, 1935, 1887; Ann. Inst. 

 Past., 58, 1937, 333.) 



mem.bran.a'ce.a. L. adj. membranaceus 

 membranaceous . 



Ellipsoidal cells commonly in pairs and 

 also solitary. 



Colonies on silica gel: Appear as dull mu- 

 coid 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, 1892. 

 (Arch. Sci. biol., St. Petersburg, 1, 1892, 127.) 



Ni.tro.bac'ter. Gr. noun nitrum nitre, M.L. nitrate; M.L. noun bacter the masculine 

 form of the Gr. neut.n. bactrum a rod; M.L. mas.n. Nitrobacter nitrate rod. 

 Cells rod-shaped. Oxidize nitrites to nitrates. 

 The type species is Nitrobacter winogradshji Winslow et al. 



1. Nitrobacter winogradskyi Winslow 

 et al., 1917. (Nitrobacter Winogradsky, 

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

 Bacterium nitrobacter Lehmann and Neu- 

 mann, Bakt. Diag., 2 Aufl., 2, 1899, 187; 

 Winslow et al.. Jour. Bact., 2, 1917, 552.) 



wi.no.grad'sky.i. Named for S. Wino- 

 gradsky, the microbiologist who first iso- 

 lated these bacteria; M.L. mas.gen.n. 

 winogradskyi of Winogradsky. 



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 microns. 

 Do 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 com- 

 pounds. 



Washed agar colonies: In 7 to 10 days 



very small, light brown, circular to irregular 

 colonies, becoming darker. 



Silica gel: Colonies smaller but more 

 dense than those on washed agar. 



Washed agar slant: In 7 to 10 days scant, 

 grayish streak. 



Inorganic solution medium: After 10 daj's 

 flocculent sediment. Sensitive to ammonium 

 salts under alkaline conditions. 



Nitrite is oxidized to nitrate. 



Aerobic. 



Strictly autotrophic. 



Optimum temperature, between 25° and 

 28° C. 



Source: Soil. 



Habitat: Presumably widely distributed 

 in soil. 



2. Nitrobacter agilis Nelson, 1931. 

 (Zent. f. Bakt., II Abt., 83, 1931, 287.) 



