Structure of Cyanobacteria (With Diagram) | Microbiology

In this article we will discuss about the structure of cyanobacteria. This will also help you to draw the structure and diagram of cyanobacteria.

1. A gelatinous sheath, made up of homogeneous surface, is present in all the Cyanobacteria. It may be thin (e.g., Anacystismontana) or thick and well developed (e.g., Anabaena). The mucilaginous sheath is made up of many cellulose fibrils ar­ranged reticulately in the homogenous matrix.

2. The cell wall is present in between mucilaginous sheath1 and plasmalemma. It is rigid and usually made up of four layers.

3. Cytoplasmic membrane is made up of two electron opaque layers of proteins separated by a less opaque lipid layer.

4. The chromatoplasm region consists of a complex lamellar system, called photosynthetic lamellae or thylakoids. These lamellae are not enclosed in membrane-bound chloroplasts, and hence differ from that of other algal groups. A photosynthetic lamella is made up of two unit membranes having a small flattened area in between. Each membrane of lamella is 70-80 Å thick.

5. The cells (Fig. 303) lack Golgi-bodies (dictyosomes), endoplasmic reticulum and mitochondria.

6. Many gas vesicles, polyglucan granules, cyanophycin granules, polyhedral bodies and lipid droplets are some of the inclusions of the cy­toplasm in a Cyanobacterial cell.

7. Ribosomes are the sites for protein synthesis.

8. The nucleoplasm region is somewhat transparent, having lower electron opacity. Many fine strands of DNA micro-fibrils are irregularly present in the nucleoplasm.

9. Nucleolus is absent.

10. The nuclear material is not bounded by nuclear membrane.