1. Coccus
Bacteria that are round in appearance are called coccus bacteria. Different types of coccus bacteria are-
(i) Micrococcus : Spherical bacteria are called Micrococcus if they are isolated or isolated. For example, Micrococcus denitrificans, Micrococcus aureus, Micrococcus flavus.
(ii) Diplococcus : Spherical bacteria in pairs or pairs are called diplococcus. For example, Diplococcus pneumonia.
(iii) Streptococcus Streptococcus: Spherical bacteria are called Streptococcus if they are arranged in chains. For example, Treptococcus lactis, Treptococcus strep and Treptococcus pyrogens.
(iv) Tetracoccus : Spherical bacterial cells divided into two different layers and arranged in groups of four are called tetracoccus. Such as Gaffkyacoccus tetragena, Tetracoccus sp.
(v) Staphylococcus : Spherical bacteria clustered together like bunches of grapes are called Staphylococcus. For example, Staphylococcus aureus.
(vi) Sarcina : A certain number of spherical bacterial cells arranged regularly is called Sarcina. For example – Sarcina lutea.
2. Bacillus
Bacteria that look rod-shaped are called bacillus. Different types of bacillus are-
(i) Monobacillus : Rod shaped bacteria are called monobacillus if they are single. For example- Bacillus albus, Escherichia coli.
(ii) Diplobacillus : When rod-shaped bacteria are arranged in pairs, they are called Diplobacillus. Lactobacillus, Corynebacterium diptheriae, Moraxella lacunata, Diplobacillus.
(iii) Streptobacillus: Rod-shaped bacteria are called Streptobacillus if they are arranged in chains. For example- Bacillus tuberculosis, Streptobacillus moniliformis.
(iv) Palisadebacillus : If the rod-shaped bacteria are parallel to each other and form a structure like oleic tissue, it is called palisade bacillus. For example, Lampropedia sp.
(v) Coccobacillus: If the bacteria are elongated or ovoid, they are called coccobacillus. For example – Salmonella, Mycobacterium, Coxiella burnetti.
3. Spirillum: Viruses that have a squiggly or coiled appearance are called Spirillum bacteria. For example, Spirillum minus, Treponema.
4. Archaic bacteria: Archaic bacteria are called archaic bacteria. For example – Vibrio cholera.
5. Pleomorphic: Bacteria that do not have a specific shape are called pleomorphic bacteria. For example, Rhizobium mayense.
6. Square shaped bacteria: Square bacteria with four arms are called square bacteria. For example, Haloquadratum.
7. Star-shaped bacteria: Bacteria that look like stars are called star-shaped bacteria. Such as- Stella humosa, Stella vacuolata.
8. Hyphae or Microscopic Bacteria: Bacteria that are long hyphae with thin walls are called microscopic bacteria. Such as Candidatus savagella, Streptomyces.