Home / Cyanobacteria / Colonies / Gloeocapsa
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Name derivation:
“Gelatinous casle” (From the Greek, gloios- glutinous, gelatinous, sticky, and kapsa- case)
Classification:
Gloeocapsa Kützing 1843; 88 of 139 species descriptions are currently accepted taxonomically (Guiry and Guiry 2013). Order Chroococcales; Family Microcystaceae
Morphology:
Colonial, cells flattened along lines of division, embedded in dense mucilage formed by concentric layers of sheath each corresponding to a round of division.
Similar genera:
Colonies of Gleocapsa usually contain more cells than Chroococcus, which often forms clusters of 4 cells that result from symmetric binary fission
N-fixation without heterocysts
Axenic cultures of Gloeocapsa sp. in nitrate-free medium formed ethylene at rates similar to known N-fixers (Wyatt and Silvey 1969).
Sunscreen: Micosporine-like amino acids MAAs)
Micosporine is includes UV-blocking compounds with absorbance at 310 – 320 nm found in a diverse group of fungal spores. Gloeocapsa sp. produces MAAs proportional to exposure to UV light (Garcia-Pichel et al. 1993).
Habitat:
Mostly on wet rocks, and less often on moist soil and other terrestrial surfaces, and in freshwater plankton .
References:
Garcia-Pichel, F., C.E. Wingard and R.W. Castenholz 1993. Evidence regarding the UV sunscreen role of a mycosporine-like compound in the cyanobacterium Gloeocapsa sp. Graham L.E. and L.W. Wilcox 2000. Algae. Prentice Hall Guiry, M.D. and G.M. Guiry 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 04 September 2013. Kützing, F.T. 1843. Phycologia generalis oder Anatomie, Physiologie und Systemkunde der Tange... Mit 80 farbig gedruckten Tafeln, gezeichnet und gravirt vom Verfasser. pp. [part 1]: [i]-xxxii, [1]-142, [part 2:] 143-458, 1, err.], pls 1-80. Leipzig: F.A. Brockhaus. Wehr, J.D. and R. G. Sheath 2003. Freshwater Algae of North America. Academic Press (Imprint of Elsevier) Wyatt, J.T. and J.K.G. Silvey 1969. Nitrogen fixation by Gloeocapsa. Science 165(3896):908-909.