FAMILY NITROBACTERIACEAE 



73 



colony appears as a bulbous, angular, 

 brown body which may become 0.5 mm. 

 in diameter. The cells are held firmly 

 together in these irregularly shaped bul- 

 bous aggregates. 



Aerobic. 



Source: Poor soils of Brie and else- 

 where in France. 



Habitat : Presumably widely distrib- 

 uted in forest and manured soils. 



A similar culture called Nitrosocystis 

 B.A. was isolated from activated sludge 

 by H. Winogradskj' (Compt. rend. Acad. 

 Sci., Paris, 200, 1935, 1888; Ann. Inst. 

 Pasteur, 58, 1937, 326). It produced 

 compact, bulbous, dented cj'st-like ag- 

 gregates of cells having a yellow color. 

 The colonies produced clear zones on 

 silica gel coated with CaCOs. These 

 cysts were composed of oval or elongated 

 coccoid cells imbedded in mucus and sur- 

 rounded by a thickened capsule, com- 



posed of two layers. The cells become 

 dispersed from the cysts as motile cells 

 and form new colonies. This culture 

 differs from A^. coccoides in that the 

 colonies have a pale reddish yellow color 

 and the oval cells are 0.5 by 1.5 microns 

 in size. 



Cultures of N itrosocystis were obtained 

 by Rommell (Svensk. botan. Tidskrift, 

 26, 1932, 303) from forest soils. Ivingma 

 Boltjes (Arch. f. Mikrobiol., 6, 1935, 79) 

 obtained cultures which produced masses 

 of cells, some of which were loose and 

 others compact. They were not believed 

 to be true zoogloea since no capsule or 

 slimy substance was noted. The de- 

 velopment of true cysts by nitrifying 

 bacteria was questioned. Winogradsky 

 (Bull. d. I'Inst. Pasteur, 33, 1935, 1074) 

 concluded that Kingma Boltjes worked 

 with a culture of Nitrosocystis and not of 

 NilrosomoJias as was believed. 



Genus V. Nitrosogloea H. Winogradsky. 

 (Compt. rend. Acad. Sci., Paris, £00, 1935, 1887; Ann. Inst. Pasteur, 58, 1937, 335.) 



Cells ellipsoidal or rod-shaped. Embedded in slime to form zoogloea. No common 

 membrane surrounds the cells aggregates. Oxidize ammonia to nitrite. From Latin, 

 nitrosus, full of soda; and Greek, gloea, glue, jelly; M.L. nitrous jelly. 



The type species is Nitrosogloea merismoides H. Winogradsky. 



1. Nitrosogloea merismoides H. Wino- 

 gradsky. {Nitrosocystis "/", H. Wino- 

 gradsky, 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 

 Greek, merismos, a dividing, division; 

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



Ellipsoidal cells: 0.5 by 1.5 microns. 

 Oval cells or short rods forming tetrads 

 or chains, each group with its own sheath. 

 The groups vary in shape to produce 

 branched chains, irregular or compact 

 aggregates. 



Colonies on silica gel : Cells encased in 

 a pale yellow mucilage giving the colony 

 a dull appearance. Colony surface stud- 

 ded with little humps. 



Aerobic. 



Source: Activated sludge. 



Habitat: Unknown. 



2. Nitrosogloea schizobacteroides H. 



Winogradsky. (Nitrosocystis "77", 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 

 Greek, schizo, to split; bakterion, a small 

 rod; eidos, form, shape; M.L. like a divid- 

 ing rod. 



Rods: Elongated rods or short fila- 

 ments 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 



