| Morphology | Lyngbya |
| CELLULAR |
| Staining | |
| Morphology | |
| Motility | |
| 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 |
| Division |
| COLONIAL |
| 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 |
| PHYSIOLOGICAL |
| Tropism | |
| Oxygen | |
| pH | |
| Temperature | |
| Requirements | |
| Products | |
| 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.). |
| ENVIRONMENTAL |
| 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. |
| Lifestyle | |
| Pathogenicity |
| Distribution |
| 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 |
| References |