70 MANUAL OF DETERMINATIVE BACTERIOLOGY 



C. Organisms oxidize sulfur or thiosulfate and similar inorganic compounds of 

 sulfur. 



Tribe III. Thiobacilleae, p. 78. 

 a. Aerobic to anaerobic, non-spore-forming rods with a single polar flagellum 

 on each (so far as known), or non-motile. 



Genus I. Thiohacillus, p. 78. 



TRIBE I. NITROBACTERIEAE WINSLOW ET AL. 



(Jour. Bact., 5, 1920, 201.) 



Organisms deriving energy from the o.xidation of ammonia to nitrite or from 

 nitrite to nitrate and depend on this oxidation for growth. Fail to grow on media 

 containing organic matter in the absence of the specific inorganic materials used as 

 sources of energy. Many organic compounds commonly used in standard culture 

 media are toxic to this group. 



Genus I. Nitrosomonas Winogradsky. 



{Nitromonas Winogradsky, Ann. Inst. Past., ^, 1890, 257; Arch. Sci. biol., St. Peters' 

 burg, 1, 1892, 127; emend. S. and H. Winogradsky, Ann. Inst. Past. 50, 1933, 350.) 



Cells ellipsoidal, non-motile or with a single polar flagellum, occurring singly, in 

 pairs, short chains or irregular masses, which are not enclosed in a common membrane. 

 Oxidize ammonia to nitrite more rapidly than the other genera of this tribe. From 

 Latin, nitrosus, full of soda; M.L. nitrous; and Greek monas, a unit; M.L. a monad. 



The type species is Nitrosomonas europaea Winogradsky. 



1. Nitrosomonas europaea Winograd- Small, compact, sharply defined colo- 



sky. (Arch. Sci. biol., St. Petersburg, nies brownish in color on silica gel. 



1, 1892, 127; Bacterium nitrosomonas Aerobic. 



Lehmann and Neumann, Bakt. Diag., Strictly autotrophic. 



2nd ed., 2, 1899, 187; Pseudomonas Source: Soils of Zurich, Switzerland; 



europaea Migula, in Engler and Prantl, of Gennevilliers, France; and Kazan, 



Die natiirl. Pflanzenfam., 1, la, 1895, 29; Russia. 



Planococcus europaeus Vuillemin, Ann. Habitat: Presumably widely distrib- 



Mycologie, Berlin, 11, 1913, 525.) From uted in soil. 

 Latin, europaeus, of Europe. 



Rods: 0.9 to 1.0 by 1.1 to 1.8 microns la. Nitrosomonas europaea var. italica 



occurring singly, rarely in chains of three Perotti (Rendic. d. Accad. d. Lincei 



to four. Possess a single polar flagellum Roma, 15, 1906, 516; Abs. in Cent. f. 



3 to 4 times the length of the rods, or Bakt., II Abt., 19, 1907, 337). Also see 



rarely one at either end. Engel and Skallau (Cent. f. Bakt., II 



Grow readily in aqueous media with- Abt., 97, 305, 1937). 

 out organic matter, and containing am- 

 monium sulfate, potassium phosphate, 2. Nitrosomonas monocella Nelson, 

 and magnesium carbonate. The cells (Cent. f. Bakt., II Abt., 83, 1931, 287.) 

 accumulate in soft masses around the From Greek monos, single and Latin 

 particles of magnesium carbonate at the cella, room; M.L. single cell, 

 bottom of the flask. The liquid is occa- Ovoid rods: 0.6 to 0.9 micron, often 

 sionally turbid through development of occurring in pairs. Young cells nearly 

 motile swarmer cells or monads. spherical. Motile by means of a single 



