Rhodocyclus

Cross Index	Rhodocyclus
SuperSet	Prokaryote, Eubacteria Anoxygenic Phototrophic Bacteria
Compare	Purple Bacteria Internal sulfur granulesAmoebobacter, Chromatium, Lamprobacter modestohalophilus, Lamprocystis roseopersicina, Thiocapsa, Thiocystis, Thiodicyton, Thiopedia rosea , Thiospirillum jenense, External sulfur granules Ectothiorhodospira no granules Rhodobacter, Rhodocyclus, Rhodomicrobium vannieli, Rhodopila globiformis, Rhodopseudomonas, Rhodospirillum, Green Bacteria Sulfur granules Anachloris perfilievii, Chlorobium, Chloroherpeton thalassium, Pelodictyon, Prosthecachloris no sulfur granules Heliobacillus mobilis, Heliobacterium chlorum Multicellular filamentous Chloroflexus aurantiacus, Chloronema, Heliothrix oregonensis, Oscillochloris Anaerobic chemotropic Erythrobacter longus,
Contrast	Oxygenic Phototrophic Bacteria Archaea
Subset

Morphology

Rhodocyclus

CELLULAR

Staining	Gram-negative
Morphology	Cells are ovoid or rod-shaped, 0.3-0.7 um in diameter, and., may produce capsules and slime, and may form chains of cells..
Motility	Rhodocyclus pupureus is non motile Rhodocylcus tennuis and Rhodocyclus gelatinosus have polar flagella
Specialized structures	Internal photosynthetic membranes are present as vesicles

Division

binary fission

COLONIAL

Solid surface

Liquid

Rhodocyclus gelatinosus produces a large amount of slime during active growth which causes semdimentation of the cells into a gelatinous layer

Growth Parameters

Rhodocyclus

PHYSIOLOGICAL

Tropism	Photoautotrophic growth is possible in the presence of molecular hydrogen as an electron donor Growth occurs photo-heterotrophically under anaerobic conditions in the light with a variety of organic compounds as carbon and electron sources. Most species perform an oxidative metabolism and grow as chemoheterotrophs at the full oxygen tension of air in the dark.
Oxygen	growth preferably under anaerobic conditions in the light but Rhodocyclus can grow microaerobically or aerobically in the dark
pH	pH 5.2- 7.5 optimum pH 6.0
Temperature	optimum 30 ^o C
Requirements	Rhodocyclus purpureus requires vitamin B₁₂
Products	Photosynthetic pigments are bacteriochlorophyll a and carotenoids of the spheroidene series
Enzymes
Unique features

ENVIRONMENTAL

Distribution

Genome

Rhodocyclus

G+C Mol %

64.8-72.4 (Bd)

Reference	Rhodocyclus
First citation	Pfennig, N.1978. Rhodocyclus purpureus gen. nov. and sp. nov., a ring-shpaed, vitamin B₁₂ requiring member of the family Rhodospirillaceae IJSB 28: 283-288
The Prokaryotes
Bergey's Systematatic	p 1678 J. F. Imhoff and H. G. Truper
Bergey's Determinative	p 358
References