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Morphological diversity of microbes

M
misbah malik

This document discusses the various shapes, sizes, and arrangements of microbial cells. It notes that bacteria sizes range from 0.1 to 60 micrometers, and that their shapes include spherical (cocci), rods (bacilli), spirals, and other irregular shapes. The arrangement of cocci is more complex than bacilli, depending on how the cells adhere after division. Common coccus arrangements include diplococci, streptococci, tetracocci, and staphylococci. Bacilli typically divide across their short axis into mono-bacilli, diplobacilli, or streptobacilli. Spirilla can take vibroid or helical shapes. Other microbial cell types include pleomorphic

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Prepared by : Dr Misbah Ajaz Dept of Microbiology,BGSBU,Rajouri
Size, shape and arrangement of microbial cells vary with species Bacteria are of about 0.1 to 60 6 袖m in size Bacilli =5 0.4-0.7 袖m, Pseudomonads =0.4-0.7 袖m diameter, 2- 3 袖m length) Micrococci =about 0.5袖m diameter
Morphological diversity of microbes
Generally, the bacterial cells are spherical (coccus, plural cocci which mean berries) Elongated rods (Bacillus, plural bacilli), helical rods (Spirillum, plural spirilli) Pear-shaped (Pasteurid), lobed spheres (Sulf olobus), rods with squared ends (Bacillus anthracis) Rods with helically sculptured surface (Seliberid) and of changing shape (pleomorphic), etc. Unicellular cyanobacterial cells are usually spherical (Chroococcus, Scenedesmus, Anacystis) Some are elongated and multicellular.
Arrangement of cells is more complex in cocci than bacilli. The arrangement of cells depends upon adherence of cells together after the cell division
COCCUS FORMS: Diplococcus Streptococcus Tetracocci Straphylococci Sarcinae: BACILLUS FORMS Mono-bacillus Diplobacillus Streptobacillus Coccobacillus
FORMS OF SPIRILLI Vibrioid Helical OTHER FORMS Pleomorphic Trichomes Palisade Hyphae
There are several groups of cocci based on the number and arrangement of cells. (a) Diplococcus: Cells divide in one plane and get attached permanently in pairs. (b) Streptococcus: Cells divide in one plane and remain attached to form a linear chain of cells. i) Coccus Form
(c)Tetracocci: Cells divide in two planes and form groups of four cells. (d) Straphylococci: Cells divide in three planes in an irregular pattern producing bunches of cocci. (e) Sarcinae: Cells divide in three planes in regular pattern producing bunches of cocci.
There are a few groups of bacilli unlike cocci as the former divide across their short aries. (a) Mono-bacillus: The single elongated cells freely present in nature are mono- bacillus. (b) Diplobacillus: After division the cells remain adhered and appear in paired form. (c) Streptobacillus: After division the cells remain attached in chains appearing like straws. (d) Coccobacillus: The oval cells looking like cocci are called coccobacilli There is two meaning of bacillus, one is the form and the second is the genus. For example the bacterium Bacillus anthracis causes anthrax disease.
(a) Vibrioid: Bacterial cells having less than one complete twist form vibrioid shape e.g. Vibrio cholerae. (b) Helical: Cells that have more than one twist form a distinct helical shape e.g. Spirillum (with flagella).
(a) Pleomorphic: Of changing forms e.g. Rhizobium, Mycoplasma, etc. (b) Trichomes: Cells divide in one plane forming a chain which has much larger area of contact between the adjacent cells e.g. Baggiatoa, Saprospria. (c) Palisade: The cells are arranged laterally (side by side) to form a match sticks like structure and at angles to one another e.g. Corynebacterimn diphtheriae.
(d) Hyphae: Some microorganisms form the multicellular, thin-walled, profusely branched filaments called hyphae. The interwoven hyphae are collectively known as mycelium e.g. Streptomyces, Aspergillus, and Penicillium. The cyanobacterial cells are comparatively larger than the bacterial cells. In addition, the cell size of eukaryotes such as algae, fungi, protozoa, etc. is several times greater than the cells of prokaryotes. The unicellular Cyanobacteria are usually spherical or elongated. The fungi are either unicellular (yeast, Candida) or multicellular hyphal (Fusarium, Aspergillus) forms.
Morphological diversity of microbes
Morphological diversity of microbes
Morphological diversity of microbes
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Morphological diversity of microbes

  • 1. Prepared by : Dr Misbah Ajaz Dept of Microbiology,BGSBU,Rajouri
  • 2. Size, shape and arrangement of microbial cells vary with species Bacteria are of about 0.1 to 60 6 袖m in size Bacilli =5 0.4-0.7 袖m, Pseudomonads =0.4-0.7 袖m diameter, 2- 3 袖m length) Micrococci =about 0.5袖m diameter
  • 4. Generally, the bacterial cells are spherical (coccus, plural cocci which mean berries) Elongated rods (Bacillus, plural bacilli), helical rods (Spirillum, plural spirilli) Pear-shaped (Pasteurid), lobed spheres (Sulf olobus), rods with squared ends (Bacillus anthracis) Rods with helically sculptured surface (Seliberid) and of changing shape (pleomorphic), etc. Unicellular cyanobacterial cells are usually spherical (Chroococcus, Scenedesmus, Anacystis) Some are elongated and multicellular.
  • 5. Arrangement of cells is more complex in cocci than bacilli. The arrangement of cells depends upon adherence of cells together after the cell division
  • 6. COCCUS FORMS: Diplococcus Streptococcus Tetracocci Straphylococci Sarcinae: BACILLUS FORMS Mono-bacillus Diplobacillus Streptobacillus Coccobacillus
  • 7. FORMS OF SPIRILLI Vibrioid Helical OTHER FORMS Pleomorphic Trichomes Palisade Hyphae
  • 8. There are several groups of cocci based on the number and arrangement of cells. (a) Diplococcus: Cells divide in one plane and get attached permanently in pairs. (b) Streptococcus: Cells divide in one plane and remain attached to form a linear chain of cells. i) Coccus Form
  • 9. (c)Tetracocci: Cells divide in two planes and form groups of four cells. (d) Straphylococci: Cells divide in three planes in an irregular pattern producing bunches of cocci. (e) Sarcinae: Cells divide in three planes in regular pattern producing bunches of cocci.
  • 10. There are a few groups of bacilli unlike cocci as the former divide across their short aries. (a) Mono-bacillus: The single elongated cells freely present in nature are mono- bacillus. (b) Diplobacillus: After division the cells remain adhered and appear in paired form. (c) Streptobacillus: After division the cells remain attached in chains appearing like straws. (d) Coccobacillus: The oval cells looking like cocci are called coccobacilli There is two meaning of bacillus, one is the form and the second is the genus. For example the bacterium Bacillus anthracis causes anthrax disease.
  • 11. (a) Vibrioid: Bacterial cells having less than one complete twist form vibrioid shape e.g. Vibrio cholerae. (b) Helical: Cells that have more than one twist form a distinct helical shape e.g. Spirillum (with flagella).
  • 12. (a) Pleomorphic: Of changing forms e.g. Rhizobium, Mycoplasma, etc. (b) Trichomes: Cells divide in one plane forming a chain which has much larger area of contact between the adjacent cells e.g. Baggiatoa, Saprospria. (c) Palisade: The cells are arranged laterally (side by side) to form a match sticks like structure and at angles to one another e.g. Corynebacterimn diphtheriae.
  • 13. (d) Hyphae: Some microorganisms form the multicellular, thin-walled, profusely branched filaments called hyphae. The interwoven hyphae are collectively known as mycelium e.g. Streptomyces, Aspergillus, and Penicillium. The cyanobacterial cells are comparatively larger than the bacterial cells. In addition, the cell size of eukaryotes such as algae, fungi, protozoa, etc. is several times greater than the cells of prokaryotes. The unicellular Cyanobacteria are usually spherical or elongated. The fungi are either unicellular (yeast, Candida) or multicellular hyphal (Fusarium, Aspergillus) forms.