The Fine Structure of Chlorogloea fritschii Cultured in Sodium Acetate Enriched Medium

抄録

The effects of 0.02 sodium acetate on the ultrastructure of Chlorogloea fritschii are described. Control cells contain the usual inclusions found in blue-green algae. These include structured granules, polyhedral bodies, β granules, thylakoids, ribosomes and areas of DNA. In addition, poly- β-hydroxybutyrate (PHB) gra-nules are present. In control cells these granules are quite small being approxi-mately 100mμ in diameter. They are either elongate or spherical in shape. The elongate PHB granules are limited by an 80Å thick membrane while the spherical granules are bound by a 30Å thick membrane. In material treated with sodium acetate the PHB granules increase in diameter while they decrease in number. However, there is an overall increase in the volume of the cell occupied by the granules. In addition to an increase in PHB, polyphosphate bodies also develop in the cells beginning one day after exposure to sodium acetate. The number of thylakoids in the cells decreases in material exposed to sodium acetate. After three days exposure to sodium acetate β granules also appear to accumulate phos-phate as they exhibit the characteristic sublimation in the electric beam.