874 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



Green sulfur bacteria, consisting of small ovoid to rod-shaped cells, growing in 

 association with a filamentous, colorless, central bacterium, thus forming colonies 

 of a cylindrical shape. Non-motile. The green component contains a chlorophyl- 

 lous pigment different from the common chlorophylls of green plants and from bac- 

 teriochlorophyll. Capable of photosynthesis in the presence of hydrogen sulfide, 

 without depositing sulfur globules in the cells. 



The type species is Cylindrogloca bactcrifera Perfiliev. 



1. Cylindrogloea bacterifera Perliliev. 

 (Jour . Microbiol. (Russian) , 1 , 1914, 223.) 

 From Latin bacter, rod and fero, to 

 bear. 



Individual green components ovoid to 

 rod-shaped, about 0.5 to 1 by 2 to 4 mi- 

 crons, very similar to those of the com- 

 plex Chlorobacleri am symhioticum and 

 Chlorochromatium aggregatani with which 

 they may well be identical. The central 

 filamentous bacterium is embedded in a 

 slime capsule of considerable dimensions. 

 This, in turn, is surrounded by a layer 

 of green bacteria, usually one cell thick. 

 The green organisms may form a verj^ 

 dense outer covering, or they may be 

 more sparsely distributed over the mu- 

 cus capsule. The entire unit is again 

 surrounded by a sizeable slime zone. 

 Aggregates measure about 7 to 8 microns 

 in width, and up to 50 microns in length; 

 they are non-motile. Both components 

 appear to be non-spore-forming. 



Habitat: Mud and stagnant water con- 

 taining rather high concentrations of 

 hydrogen sulfide and exposed to light. 



Illustration: Perfiliev, loc. cit., 213, 

 fig. 6-11. 



Perfiliev rightly emphasizes, as Buder 

 had done for Chloronium mirabile, the 

 provisional nature of thus using a gen- 

 eric designation for an apparently stable 

 complex composed of two different or- 

 ganisms. It remains possible that the 

 last three genera of symbiotic entities 

 represent fortuitous combinations whose 

 occurrence is conditioned by environ- 

 mental factors. If so, the generic ter- 

 minology would be devoid of any taxo- 

 nomic significance, and the green 

 bacteria should be relegated to more 

 appropriate genera. Indications sugges- 

 tive of this state of affairs can be found 

 in the literature; for example in Uter- 

 mohl's ob.servation (Archivf.H,ydrobiol., 

 Suppl. 5, 1925, 279) that the complex 

 Chlorochromalium aggregalum may, espe- 

 cially in the presence of oxygen, dis- 

 integrate, whereupon the green con- 

 stituents appear as small Pelodictyon 

 aggregalum (Schmidlea luteola) colonies. 



