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MANUAL OF DETERMINATIVE BACTERIOLOGY 



1. Nitrosospira briensis Winogradsky. 

 (Ann. Inst. Pasteur, 50, 1933, 407.) From 

 French, Brie, a place name; M.L. of 

 Brie. 



Spirals wound tiglitly to form very 

 small cylinders as long as 15 to 20 mi- 

 crons. Short spirals have the appearance 

 of short rods and ellipsoidal cells. Small 

 pseudo-cocci were observed in old cul- 

 tures. 



Colonies on silica gel : Small colonies 

 which occasionally contain cyst-like ag- 

 gregates of cells. The cysts are more 

 poorly developed than in Nitrosocystis. 



Aerobic. 



Reaction optimum: pH 7.0 to 7.2. 



Source : Uncultivated pasture soil of 

 Brie, France. 



Habitat : Presumably widely distrib- 

 uted in soil. 



2. Nitrosospira antarctica Winograd- 

 sky. (Ann. Inst. Pasteur, 50, 1933, 407.) 

 From Greek, antai-kitos , southern, 

 antarctic. 



Cells and colonies similar to A'^. brien- 

 sis except that the cells are generally 

 wound together to form more compact 

 spirals. 



Aerobic. 



Reaction optimum: pH 7.0 to 7.2 



Source: Soil from the Antarctic. 



Habitat : Presumably widely distrib- 

 uted in soil. 



Genus IV. Nitrosocystis Winogradsky. 

 (Compt. rend. Acad. Sci., Paris, 192, 1931, 1003; Ann. Inst. Pasteur, 50, 1933, 399.) 



Cells ellipsoidal or elongated, uniting in compact, rounded aggregates surrounded 

 by a common membrane to form cysts. The cysts disintegrate to free the cells, par- 

 ticularly when transferred to fresh media. Within the cyst, the cells are embedded 

 in slime. Oxidize ammonia to nitrite at a rate intermediate between Nitrosomonas 

 and Nitrosospira. From Latin, nitrosus, full of soda; and Greek, kystis, bladder; 

 M.L. nitrous cyst. 



The type species is Nitrosocystis javanensis comb. nov. 



1. Nitrosocystis javanensis comb. nov. 

 {Nitrosomonas javanensis Winogradsky, 

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

 127; Pseudomonas javanensis Migula, 

 in Engler and Prantl, Die natlirl. 

 Pflanzenfam., 1, la, 1895, 30; Compt. 

 rend. Acad. Sci., Paris, 192, 1931, 1003.) 

 From Latin, of Java. 



Small ellipsoidal cells having a diam- 

 eter of 0.5 to 0.6 micron. Possess a polar 

 flagellum 20 times as long as the rods. 



In liquid medium produces very com- 

 pact zoogloeal masses of cells and motile 

 swarmers. The large zoogloea are them- 

 selves composed of smaller compact 

 aggregates of cells. 



On silica gel the colonies are circular to 

 elliptical becoming clear or light brown. 



Aerobic. 



Strictly autotrophic. 



Source: Soil of Buitenzorg, Java; 

 Tokyo, Japan; La Reghaia, Tunisia. 



Habitat : Presumably widely distrib- 

 uted in soil. 



2. Nitrosocystis coccoides nom. nov. 

 (Nitrosocystis a, S. Winogradsky and H. 

 Winogradsky, Ann. Inst. Pasteur, 50, 

 1933, 401.) From Greek, kokkos, a grain; 

 eidos, form, shape; M.L. coccus-like. 



Ellipsoidal cells about 1.5 microns in 

 diameter. Occur as compact aggregates 

 of cells imbedded in mucus and sur- 

 rounded by a thickened capsule to form 

 cyst-like bodies. Cells rarely solitary 

 but more often in pairs and in small 

 groups of four or more. Probably motile. 

 The mucus which surrounds the cells is 

 not readily stained, whereas the outside 

 coating stains more easily. 



Colonies on silica gel : As colonies de- 

 velop, the coating of CaCOs on the gel 

 becomes yellowish and dissolves and the 



