Cyanobacterial Morphology
There are three main morphological differentiations carried out by Cyanobacteria...
heterocyst
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Specialist nitrogen fixing cyanobacteria.
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1 cell per 10-20 vegetative cells differentiates into a heterocyst.
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Thick cell walls, helping to create a microanaerobic environement so that the enzyme nitrogenase can function to fix atmopspheric nitrogen.
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Work together with the vegetative cells of the filament to share fixed nitrogen in return for fixed carbon sources.
akinete
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Spore-like cells of cyanobacteria.
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Thick cell walls.
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Differentiate to survive through periods of darkness, desiccation, freeze thaw cycles and nutrient deficiency.
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Not very resistant to heat (like bacterial endospores).
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Viable akinetes have been found in sediments up to 64 years old.
hormogonia
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Motile differentiations of cyanobacteria.
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Small fragments will break off from the main filament and move away.
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Develop during times of stress.
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Move by gliding motility (no flagellum).
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Can be used in order to move away or towards a certain stimulus.
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Crutial for the creation of symbioses with plant species (for the sharing of fixed nitrogen by heterocysts).
