[Ultrastructure of Spirulina in comparison with Oscillatoria]

The following filamentous blue-green algae: S. platensis, S. platensis f. minor and S. princeps were observed under electronmicroscope and were compared with two species of the related genera Oscillatoria: O. rubescens and O. chalybea. From our research it was resulted that Spirulina is characterized by a more dense cellular content and by a more wide thylakoid system. The protoplasm shows various types of inclusions: polyglucan granules, lipid droplets, eyanophycin granules, polyhedral bodies, polyphosphate granules and gas vacuoles. In addition Sprulina presents few aggregated membranes with non photosynthetic character and therefore can be compared with ""Memosome'' of bacteria. Spirulina contains more polyhedral bodies and cyanophycin granules and more proteins than Oscillatoria.