Cross Index Anabaena
SuperSet Prokaryote, Eubacteria Oxygenic Phototrophic Bacteria
Compare Cyanobacteria

Prochlorales Procloron didemni, Prochlorothrix hollandica
Contrast Anoxygenic Phototrophic Bacteria
Archaea
Subset  

 

Morphology Anabaena
CELLULAR  
Staining  
Morphology  
Motility  
Specialized structures Trichomes are untapered with conspicuous constrictions at cross- walls. Trichomes may be straight, curved or helically (spirally) formed. The cells are cylindrical, spherical or ovoid (barrel- shaped) and not shorter than broad (or only slightly so), usually ranging in width from about 2 to 10 um but in some species to over 20 um (Desikachary, 1959). The terminal cells may be rounded, tapered or conical in shape. Heterocysts are intercalary or terminal or both Intercalary heterocysts are nearly spherical to cylindrical with rounded ends; terminal heterocysts are similar or sometimes conical. Akinetes are usually formed, and their position in trichomes differs with the species. A firm individual sheath is absent, but a soft mucilaginous covering is often present. Trichomes, when free of adhesive mucilage, are normally motile (usually <1 um/s), and colonies are not formed. Reproduction is by fragmentation of "parental" trichomes into shorter trichomes indistinguishable in cell dimensions from the former trichome. Gas vesicles occur in many species; however, they occur mainly in those that are planktonic
Division  
COLONIAL  
Solid surface  
Liquid  

 

Growth Parameters Anabaena
PHYSIOLOGICAL  
Tropism Some culture strains of Anabaena are well known as facultative heterotrophs (Wolk 1980). Seven strains in the Pasteur Culture Collection were judged to be obligatephototrophs (Rippka et al. 1979).
Oxygen  
pH  
Temperature  
Requirements nitrogen is often the limiting nutrient
Products many contain phycoerythrocyanin in addition to phycocyanin, but species exist that are reddish, i.e. containing phycoerythrin and phycocyanin.
Enzymes  
Unique features  
ENVIRONMENTAL  
Habitat Many species are known worldwide as major components of the freshwater plankton and also of many saline lakes. Others occur as tychoplankton

There are at least 15 gas-vacuolate species in freshwater, and A. spiroides, A. circinalis and A. flos-aquae are the most common in the plankton

Anabaena flos-aquae, has invaded brackish marine environments such as the

low-salinity portions of the Baltic Sea.
Lifestyle a few are symbiotic (eg. Anabaena azollae of the aquatic fern Azolla), although in association with host species it is often difficult to distinguish Anabaena and Nostoc. Most of the symbiotic strains are ascribed to the genus Nostoc.
Pathogenicity  
Distribution Anabaena is not known as a major component of marine plankton,

nitrogen-limited pelagic marine environments are dominated primarily by the oscillatorian genus Trichodesmium,

 

Genome Anabaena
G+C Mol % The mol% G + C of the DNA of 19 strains ranged from about 35 to 47 (Herdman et al. 1979a; Stulp and Stam 1984b; Florenzano et al. 1985). The genome size of six strains ranged from 3.17 to 3.89 x 10-9 daltons (Herdman et al. 1979b
   

 

Reference Anabaena
First citation Bory de St. Vincent 1822 cited but not referenced
The Prokaryotes  
Bergey's Systematatic p 1783 R.W. Castenholz
Bergey's Determinative p 403
References The most extensive studies of cyanobacterial nitrogen fixation and of heterocyst structure and differentiation have used Anabaena (Stewart 1980; Wolk 1989).