Phosphate Metabolism in Blue-green Algae

The fine structural morphology of polyphosphate bodies is described after a variety of fixation and post-staining procedures. Glutaraldehyde fixation alone or in combination with osmium tetroxide provides the best preservation of polyphosphate bodies. Post-staining in uranyl acetate and lead citrate alone or in combination seems to extract polyphosphate bodies to varying degrees. Three morphological types of polyphosphate bodies are described; electron dense, porous, and those having an electron transparent center with an electron dense periphery. The effect of fixation, post-staining and electron beam on these bodies is described. Thick sections (0.5, μm) observed at 100 KV also reveal these three morphologies. The authors suggest that investigators should observe unstained glutaraldehyde fixed sections to determine if polyphosphate bodies are present in their material.