Cross Index Lyngbya
SuperSet Prokaryote, Eubacteria ,Oxygenic Phototrophic Bacteriaand Sheathed bacteria
Compare Cyanobacteria

Prochlorales Procloron didemni, Prochlorothrix hollandica

Sheathed heterotrophs

The genus Lyngbya which is one of the cyanobacteria has a sheath.

Herpetosiphon, Thioploca and Thiothrix nivea which also have sheaths are a lso included in Nonphotosynthetic, Nonfruiting Gliding Bacteria in the non fruiting section.

Clonothrix fusca Crenothrix polyspora, Haliscomenobacter hydrossis, Leptothrix, Lieskeella bifida Phragmidiothrix multiseptata Sphaerotilus natans , Thioploca, Thiothrix nivea, Herpetosiphon

Contrast Anoxygenic Phototrophic Bacteria


Morphology Lyngbya
Specialized structures Filamentous organisms that share the entire range of cellular types with Oscillatoria but which produce a distinct and persistent sheath. The sheath may be thin but can be seen with phase-contrast optics, particularly where it extends beyond the terminal cell of the trichome The trichome diameters range from about 1 um to about 80 um. Cell features are the same as for the description of Oscillatoria, including coloration. Trichomes are usually nonmotile within the sheath, but short sections of trichome (hormogonia) sometimes move slowly when placed on new agar-solidified medium. Some strains produce many hormogonia which glide free of the sheaths and appear as Oscillatoria until new sheath production again immobilizes them. In some cases, rapid growth extends trichomes out of old sheaths, and terminal portions appear sheathlessThe sheaths of some strains, including PCC 7419, are quite prominent and strong, so that an entire entangled mass of filaments in liquid culture will hold together if attempts are made to remove only a small part with forceps. Laminated sheaths occur commonly in the large diameter species

Gas-vacuolate forms are uncommon (Walsby 1981

Solid surface On agar the production of motile hormogonia is not assured, and the older sheaths sometimes carry a heavy burden of attached, contaminating microorganisms.
Liquid A yellow pigment ("scytonemin") commonly occurs in the sheaths of some marine mat- forming species, giving the whole filament a brownish colour. Although little is known about this pigment, the broad absorption maximum lies in the near UV, violet, and blue regions of the spectrum (Muehlstein and Castenholz 1983). In some species,

intense purple to red pigments occur in multilayered sheaths (i.e. Porphyrosiphon Kutzing 1849).

Growth Parameters Lyngbya
Enzymes In reference strain PCC 7419, a marine mat-forming type, nitrogenase was synthesized under sustained anaerobic conditions (Rippka et al. 1979
Unique features Growth rates of the thicker- sheathed species also appear commonly to be about an order of magnitude slower than those of most Oscillatoria species known in culture. The first reference strain (PCC 7419) was separated by Rippka et al. (1979) from the "LPP group" as the single member of LPP-A, and is characterized by having a thick and persistent sheath, wide trichome (15-16 um) and short disklike cells. Since Lyngbya as a distinct taxonomic unit is still uncertain, little can be said regarding the physiology of the group.).
Habitat a worldwide distribution. In contrast to Oscillatoria, however, few species are planktonic

Lyngbya (including Phormidium) also forms fabriclike mats in shallow marine (including intertidal) and freshwater habitats. In general, the thicker-sheathed species of Lyngbya are more difficult to isolate in culture than are Oscillatoria species.



Genome Lyngbya
G+C Mol % 42 to 49., 43.4 (Herdman et al 1979a) for reference strain (PCC 7419, ATCC 29346),
  the genome size is about 4.58 x 109 daltons (Herdman et al. 1979b). However, with the present concept of Lyngbya, others of the "LPP group" would also fall within this generic boundary, since most have at least thin sheaths (see Table 15 in Rippka et al. 1979). Stam (1980) included several sheathed "oscillatorian" forms in his DNA/DNA hybridization studies. in both freshwater and marine forms.


Reference Lyngbya
First citation Agardh.C.A.. 1824. Systema Algarum, Litteris Berlingianis, Lund Sweden, 312 pp.
The Prokaryotes  
Bergey's Systematatic p 1777 R.W. Castenholz
Bergey's Determinative p 393