Abstract
The cyanobacterium Mastigocladus laminosus produces motile hormogonia which move by gliding motility. These hormogonia were characterized in terms of their morphology, state of differentiation of the cells, optimal temperature for production and motility, minimal nutritional requirements to sustain motility, liberation of the hormogonium from its parental trichome, average surface velocity, and maximal concentration of agar through which the hormogonium may move. We found that an average hormogonium consisted of 13.6 cells of only the narrow-cell-type morphology. Gliding motility and the production of hormogonia were maximal at 45 degrees C. Agarose plus 0.20 mM Ca2+ was sufficient to sustain gliding motility. Hormogonia were liberated from the parental trichome by formation and lysis of a necridium. The average surface velocity of a hormogonium was 1.7 micron/s with a maximal velocity of 3 micron/s. Hormogonia were motile through 7% agar. Motile hormogonia leave a record of their passage in the form of easily visible tracks on the surface of solid media. Three types of tracks were observed: straight, sinusoidal, and circular. Normal, forward-directed motion involves screwlike rotation that describes a right-handed helix. However, observations are presented which suggest that rotational motion is not a prerequisite for gliding motility in this cyanobacterium.
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- Burchard R. P. Gliding motility of prokaryotes: ultrastructure, physiology, and genetics. Annu Rev Microbiol. 1981;35:497–529. doi: 10.1146/annurev.mi.35.100181.002433. [DOI] [PubMed] [Google Scholar]
- Halfen L. N., Castenholz R. W. Gliding in a blue-green alga: a possible mechanism. Nature. 1970 Mar 21;225(5238):1163–1165. doi: 10.1038/2251163a0. [DOI] [PubMed] [Google Scholar]
- Lamont H. C. Shear-oriented microfibrils in the mucilaginous investments of two motile oscillatoriacean blue-green algae. J Bacteriol. 1969 Jan;97(1):350–361. doi: 10.1128/jb.97.1.350-361.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mendelson N. H. Bacterial growth and division: genes, structures, forces, and clocks. Microbiol Rev. 1982 Sep;46(3):341–375. doi: 10.1128/mr.46.3.341-375.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nierzwicki-Bauer S. A., Balkwill D. L., Stevens S. E., Jr Heterocyst differentiation in the cyanobacterium Mastigocladus laminosus. J Bacteriol. 1984 Feb;157(2):514–525. doi: 10.1128/jb.157.2.514-525.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rzhanova G. N. Vnekletochnye azotsoderzhashchie veshchestva dvukh azotfiksiruiushchikh vodov sinezlenykh vodoroslei. Mikrobiologiia. 1967 Jul-Aug;36(4):639–645. [PubMed] [Google Scholar]