This document provides information about the structure and components of bacterial cells. It discusses the various organelles found in bacteria, including the cell wall, plasma membrane, flagella, pili, and capsule. It describes the composition and functions of these structures. The document also provides diagrams to illustrate the arrangement of bacterial cells and organelles like flagella and pili.

1. Prepared by
Miss Wadekar Pradnya Pradeep
Mr. More Mangesh Rajendra
Assistant Professor,
Department of Pharmaceutics,
Appasaheb Birnale College of Pharmacy, Sangli
MS, INDIA.
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2.  Unicellular prokaryotes
 Contain both DNA and RNA
 Present in soil, air, food and all natural environment
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3. 0.1-0.5 μm
1-8 μm
1μm in diameter
3

4. Staphylococcus aureus
Bracella
Vibrio comma
Escherichia coli
Spirillum ruprem
4

5.  Actinomycetes
 Ex Streptomyces sp.
 Mycoplasma:
 Ex. Mycoplasma pneumoniae
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6. Diplococci
Streptococci
Cocci Tetrad
Staphylococci
ARRANGEMENT Saracinae
OF BACTERIA
Diplobacilli
Bacilli Strepatobacilli
Trichomes
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7. Split in one plane and remain attached to each other
Ex. Diplococcus pneumoniae
Divide in one plane and remain attached to each
other Ex. Streptococcus lactis
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8. Divide in two planes and remain in
group ofin two planes and
Divide four
Ex. Gaffykaatetragena four
remain in group of
Ex. Gaffyka tetragena
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9. Divide in three planes in irregular pattern
Ex. Staphylococcus aureus
Sarcinae
Divide in three planes in irregular
pattern and cells are present in a
group of eight. Ex. Sacina ventriculi
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10. Bacili didvde at their short axis
Diplobacilli
Ex. Klebisella pneumoniae
Streptobacilli
Ex. Bacillus subtilis
Trichomes: Bacilili remain attached to
each other
At specific angles forming letters V and L.
Ex. Corynebacterium diphtheriae
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11. •Cell envelope=
Cytoplasmic or plasma
membrane and cell wall
•Protoplasma=
cytoplasma and
cytoplasma inclusions
•Cell may be enclosed in
loose slime layer or
capsule
•Many bacteria have
filamentous appendages
called fimbriae or pili
(organ of adhesion)
•Many bacteria have
flagella i.e. organ of
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locomotion

12.  Long, slender hair like cytoplasmic appendage
 Function- locomotion
 Size- 0.01-0.02 μm in diameter and 3-20 μm in length
 Are observed in few cocci, most of bacilli, almost all spirilla
and vibrio.
 Can be seen in ordinary optical microscope with special
staining technique consisting of increase in thickness of
flagella by means of mordant.
 Can be easily seen in electron microscope.
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13. 13

14.  Motility of bacteria can be studied by-
 Hanging drop method
 By detecting spreading growth in semi solid agar
medium.
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15. ‹#›

16.  Spirochetes exhibit swimming motility in highly viscous
media.
Ex Treponema pallidum
 Some bacteria are motile when they are in contact with the
solid surface ie gliding motility
Ex Cytophageaspecies
 Taxis- movement of bacteria towards (positive) or away
(negative) from particular stimulus
 Chemotaxis-chemical stimulus
 Phototaxis- Light stimulus
 Aerotaxis- air stimulus
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17. P
M
S
L
L ring- Lipopolysaccharide layer, P ring- Peptidoglycan layer,
S ring- in semi position membrane M ring- cytoplasmic membrane
Gram +ve have only S and M rings 17

18.  Hair like microfibrils
 Size- 0.5-2 μm in length and 5-7 nm in dia
 Thinner, shorter and numerous than flagella.
 Composed of protein pilin
 Not related to motility, found in both motile and non motile bacteria
 Are best developed in freshly isolated strains and in liquid culture, but
may disappear after subculturing.
 Functions-
 Organ of adhesion
 Sex pili for transfer of genetic material
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 Fimbriae are antigenic in nature

19. FIMBRIAE PILI
Are evenly distributed over entire cell surface Are present at the poles of cells
Number 100-200 per cell Number 1-2 per cell
Shorter than pili Longer than fimbriae
CHARACTER FLAGELLA PILI
Size Larger Smaller
Thickness Thicker Thinner
Attached to cell wall - +
Origin Plasma membrane Cell wall
Organ of locomotion + -
Organ of adhesion - +
Required for - +
conjugation
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20. 20

21.  Called as capsule or glycocalyx or sugar coat
 Is made up of amorphous organic exopolymers which deposits outside
the cell
 It is tightly attached to the cell wall while slime layer is loosely held
which may and often gets into the growth medium
 Size-
 Microcapsule= thickness less than 0.2μm
 Macrocapsule= thickness 0.2 to 10 μm
 Capsulated bacteria are non motile though they might be containing
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flagella

22. Capsules are developed in environmental favourable conditions like sugar
concentration, blood serum or growth in living host cell.
It may be composed of complex polysaccharide (Klebsiella pneumoniae),
polypeptides (Bacillus anthracis) or hyaluronic acid (Streptococcos
pyogenes)
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23. 23

24.  Acts as an antigen, hence can be visualized by specific
antibodies i.e. quelling reaction
 This phenomenon is used for rapid identification of
Neisseria meningitidis, Streptococcus pneumoniae,
Hemophilus influenzae, Klebsiella etc…
 Functions-
 Protection from antibacterial agents such as lytic
enzymes
 Inhibit phagocytosis and contribute to virulence of
pathogenic bacteria
 Protection against temporary drying by binding with
water molecules
 Block attachment with bateriophage
 Promote bacterial attachment with surface
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25.  Is a rigid structure which gives a definite shape to cell
size- 10-20 nm thick
 Comprises 20-30% of dry weight of cell
 It can seen by differential staining, plasmolysis,
microdissection, electron microscopy and using specific
antibodies.
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26. 26

27.  Cell wall is made up of peptidoglycan or murein or mucopeptide
which comprises of diaminopimelic acid(DAP), muramic acid and
teichoic acid.
 Tetrapeptide side chain and pentapeptide side chain vary species to
species
 But commonly contain L-alanine, D-alannine, D-glutamic acid and
diaminopimelic acid 27

28. 28

29. 29

30. 30

31.  Functions-
 Is involved in growth and cell division
 Gives shape to cell
 Protection to internal structure and acts as
supporting layer
 Provides attachment to complement
 Receptor site for phages and colicin
 Shows resistance to harmful effects of
environment
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32.  Thin lining that separates the cell
wall and the cytoplasma
 Prokaryotic plasma membrane is
less rigid than that of eukaryots
due lack in sterols
 It is composed of phospholipids
(20-30%) and proteins (60-70%)
 The phospholipids are arranged in
two parallel rows called
phospholipid bilayer.
 Each phospholipid contains a
polar head, composed of
phosphate group and glycerol.
 While the nonpolar tails are in
interior of the bilayer.
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33. 33

34. • The plasma membrane integral proteins and peripheral
proteins
• The integral proteins are tightly bound and can be removed
by treatment of detergent
• While the peripheral proteins can be removed by mild
techniques like osmotic pressure
 Functions:
 Acts as a semipermeable membrane that controls inflow
and outflow of the metabolites to and from the
protoplasma
 Provides mechanical strength to the bacterial cell wall
 Helps on DNA replication
 Contains enzymes, permease which play role in passage
of selective nutrients through membrane
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35.  Is the suspension of organic, inorganic solutes in viscous
water solution.
 It contains nucleus, ribosome, proteins and other water
soluble components and reserve materials
 It may also contain plasmids
 While it doesn’t contain endoplasmic reticulum, Golgi
apparatus, mitochondria, and lysosomes which are present
in cytoplasma of the eukaryotic cells.
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36.  Are involved in the protein
synthesis
 Number varies as per protein
synthesis (15000/cell)
 Greater the protein synthesis,
more is the number
 During protein synthesis, they
are associated with the m-RNA,
and called as Polysomes.
 Are Ribonucleoproteins with
diameter 200 A0 and are
characterized by their
sedimentation properties
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37. •S stands for Svedber’s unit of sedimentation.
•This reflects the rate at which a molecule sediments under the
centrifugal force of a centrifuge.
•The svedberg is technically a measure of time, and is defined as exactly
10−13 seconds
•A particle’s mass, density, and shape will determine its S value
•Ex. 26S=will travel at 26 microns per second (26×10−6 m/s) under the
influence of an acceleration of a million gravities (107 m/s2). 37

38. 38

39.  It appears as oval or elongated bodies, generally one pr cell,
 It can be seen by acid or ribonuclease hydrolysis under electron
microscope or under optical microscope after staining (Feulgen
stain).
 Genome consists of single DNA molecule arranged in a circle.
 It doesn’t posses nuclear membrane
 nucleolus and deoxynucleoprotein.
 It is haploid
 Replicates by simple binary fission
 Plasmids: extra nuclear DNA,
Contribute in drug resistance,
conjugation ability, pathogenesis, and
nitrogen fixation ability
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40.  Endospores: spores formed inside cell
 Exospores: spores formed outside the cell
 Thick walled, highly retractile bodies
 Produced one per cell
 On germination produce single vegetative cell
 Sporulation: method of preservation and not reproduction
 Extremely resistant to desiccation, staining, disinfectant,
chemicals, radiation, and heat.
 So can remain viable for centuries.
 They can be destroyed by moist heat sterilization.
 All endospores contain Dipicolinic acid and calcium at the
centre i.e. core
 Calcium-DPA complex is responsible for resistance of spores 40

41.  Core, inner membrane, cortex,
outer membrane, spore coat and
in few cases exosporium
 Consists of core: DNA,
components for protein
synthesis like ribosomes, t-RNA,
and enzymes.
 Cortex: consists of
peptidoglycan.
 Spore coat: made up of keratine
like protein
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42. 42

43. 43

44. 44

45. 45

46. Dorner method
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47. 47

48.  Appear as round granules
 Varies according to species and condition of
culture
 Volutin: consists of polymetaphosphates
 Albert’s or Neisser’s special staining for vloutin
 Lipid granules: polymerised beta hydroxy buteric
acid
 Sudan rd black staining procedure and by
modified Ziehl-Neelsen stain
48

49.  Michael J. Pelzar, JR, E C S Chan, Noel R Krieg. Microbiology, Tata
McGraw-Hill edition, 5th ed.
 CK Jayaram Paniker. Ananthanarayan and Paniker’s Textbook of
microbiology, Orient Longman, 7th ed.
 C Kokare. Pharmaceutical microbiology Principles and applications,
Nirali Prakashan, 7th ed.
 Josephine A. Morello, Paul A. Granato, Helen Eckel Mizer. Laboratory
Manual and Workbook in Microbiology Applications to Patient Care,
McGraw-Hill Science/Engineering/Math, 7th ed.
 Harold J. Benson. Mi c r ob i ol og i cal Ap pl ications: A Laboratory
Manual in General Microbiology, McGraw-Hill
Science/Engineering/Math , 8th ed.
 www.wikipedia.com
 www.google.com
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