Bacteria, Different sizes and Shapes of of bacteria
- 1. Introduction of Bacteria Morphology of bacteria Structure of bacteria Different shapes of bacteria Arrangements of bacteria Bacterial spores Prepared by Mr. Sakhare V. G. Assistant Professor SBSPMs B. Pharmacy College Ambajogai
- 2. Morphology of bacteria Bacteria are (Single celled) unicellular, free living, microscopic microorganism capable of performing all essential function of life. They possess both Deoxyribonucleic acid (DNA) & Ribonucleic acid (RNA). Bacteria are the Prokaryotic microorganism that do not contain chlorophyll. The bacteria are mainly found or occurred in soil, water, food & all natural environments. They can survive extremes of temperature, PH, Oxygen & Atmospheric pressure. The Antonie Van Leeuwenhoek & Robert Hooks Discovered Bacteria.
- 3. Internal Structure of bacteria
- 4. Sizes of bacteria The bacteria are small microorganism which are visible under light type of microscope. Most bacteria are 0.2 um in diameter and 2-8 um in length. Cocci are 1um in diameter. Bacilli are 1 to 8 um in length & 0.1 to 0.5um in width. According to various books the average size of most bacteria as between 0.2 to 2.0 um (micrometer) in diameter. Bacteria are stained by staining reagent and visualized under higher powers of magnification (1000x) of compound microscope. An electron microscope is used for clear visualization of internal structure of bacteria.
- 5. Shapes of bacteria 1. Cocci Cocci are small, spherical, or oval shape cells. In Greek “kokkos” means Berry . 2. Bacilli It is derived from Greek word “Bacillum” means stick. They are having rod shaped cells. E.g. Bacillus Anthracis. Structure of Cocci Structure of Bacilli
- 6. 3. Vibrios They are comma shaped, curved rods. E.g. Vibrio Comma 4. Spirilla They are longer rigid rods with several curves pr coils. They have helical shape and rigid bodies. E.g. Spirillum ruperm Structure of vibrios Structure of Spirilla
- 7. 5. Spirochetes They are slender and flexous forms. 6. Actinomycetes They are branching filamentous bacteria. They having the characteristics shape is due to presence of rigid cell wall. E.g. Streptomyces. Structure of Spirochetes Structure of Actinomycetes
- 8. 7. Mycoplasmas They are cell wall deficient bacteria and hence do not possess a stable morphology. They occurs as round & oval bodies with interlacing filamentous. Structure of Mycoplasmas
- 9. Arrangements of bacterial cells The most common method reproduction of bacteria is a Asexual binary fission Asexual binary fission means separation of the body into two new bodies. 1. One copy of DNA 2. One copy of cytokinin. In this process each cell splits by forming two new cells. Cocci are characteristics arrangement or grouping : 1. Diplococci 2. Streptococci 3. Tetracocci 4. Staphylococci 5. Sarcinae
- 10. 1. Diplococci Cocci split along one plane only tends to arrange in one pair. Eg. Diplococcus Pneumoniae.
- 11. 2. Streptococci The cells are divided in one plane and remain attached to form the Chain. E.g. Streptococcus Lactis
- 12. 3.Tetracocci Tetracocci was divided into two planes and lived in a group of four. E.g. Gaffyka Tetragena
- 13. 4. Staphylococci The Cocci cells are three planes in an irregular pattern. These cells produce bunches of Cocci in grapes. E.g. staphylococcus Aureus.
- 14. 5.Sarcinae Sarcinae cells are divided into three planes in a regular pattern. These cells produce cuboidal arrangements of eight cells.
- 15. Structure of bacterial cell
- 16. 1. Flagella The flagella are mainly found in gram positive and gram negative bacteria. The flagella are seen in ordinary light microscopes by special techniques of staining. They are visualized under electron microscope. Types of Flagella Monotrichous Lophotrichous Amphitrichous Peritrichous The flagella are made up from protein like flagellin i.e. similar to keratin of myosin and it is responsible for bacterial . The flagellum has three basic parts i.e. filament ,hook ,basal body. The bacterial motility by detecting by “Hanging drop techniques”
- 17. 2. Pili or Fimbriae Pili are hair like micro fibrils. It has 0.5 to 2 um in length 5 to 7 nm is the diameter. They are thinner shorter more numerous than flagella. They are mainly present in gram negative cells. They are composed of Protein known as Pillin. The pillin having molecular weight 18000 Daltons. They are visible under electron microscope. Major role in attachment of surface hence called as organ of adhesion. Sex pili are used to transfer of genetic material from the donor to recipient cell.
- 18. 3. Capsule The term capsule refers to a layer tightly attached to the cell wall. This are thin of size less than 0.2 um called microcapsule. The development of capsule is depends on favorable environment conditions such as sugar concentration blood serum or growth in living host. 4. Cell wall The cell wall is situated in between the capsules and Cytoplasmic membrane. It is about 10 to 20 nm in thickness and constitutes 20-30% of the dry weight of the cells. They are visible under the electron microscope. The cell wall involved in growth and division of bacteria. It gives the shave to bacteria. It also gave the protection to internal structure.
- 19. 5. Cytoplasmic membrane The Cytoplasmic membrane is thin 5 to 10nm. It is composed of phospholipid 20 to 30% and Protein 60 to 70%. It helps in DNA Replication. It provides mechanical strength to bacterial cell. Important role in passage of selective nutrients through membrane. 6. Cytoplasm The bacterial cytoplasm is a suspension or organic inorganic solutes in viscous water solution. The cytoplasm of bacteria differs from that of higher eukaryotic microorganisms. Most of the bacteria extra chromosomal DNA (plasmid DNA) is also present
- 20. Bacterial Spores Spore, a reproductive cell capable of developing into a new individual without fusion with another reproductive cell. Spores thus differ from gametes, which are reproductive cells that must fuse in pairs in order to give rise to a new individual. Spores are agents of asexual reproduction, whereas gametes are agents of sexual reproduction. Spores are produced by bacteria, fungi, algae, and plants.
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