1. BACTERIOLOGI
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2. Bacteria on Earth
Bacteria are in every environment imaginable!
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3. Size
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Fig. 2-5 Six Comparisons Among Various Living Things and Molecules 3
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4. Rod-Shaped Bacteria

5. Spherical Bacteria

6. Spirochete:
Borrelia burgdorferi
Spiral-Shaped Bacteria

7. Bacterial Morphology
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8. Bacterial Anatomy (Overview)
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9. Prokaryotic Cells
• Means “before a nucleus”
• Domains Bacteria and Archaea
• Can live in environmental extremes
• Live off diverse energy sources
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http://micro.magnet.fsu.edu/cells/bacteriacell.html http://www.daviddarling.info/encyclopedia/P/prokaryoticcell.h

10. Prokaryotic
Structures
• Cytoplasm
– A liquid material that
particles are suspended in
• Ribosomes
– Site of protein synthesis
– Located in cytoplasm
• Nucleoid
– Contains hereditary
material (DNA) of the
cell
– Located in cytoplasm
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11. Prokaryotic
•
Structures
Plasma membrane
– Encloses the cell
– Regulates material into
and out of cell
• Cell Wall
– Supports cell and
determines its shape
• Capsule
– Slime layer
– Protects
– Helps to not dry out
– Helps attach to other
cells
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12. Prokaryotic
Structures
• Flagella
– Used to swim/move
– Spins like a propeller
or whip like
• Pilli
– Hair or threadlike
structures
– Help stick to other
cells for mating or
animal cells for food
and protection
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13. Cytoplasm
• Composed largely of water, together with proteins, nucleic
acid, lipids and small amount of sugars and salts
• R ib os om e s : numerous, 15-20nm in diameter with 70S;
distributed throughout the cytoplasm; sensitive to
streptomycin and erythromycin site of protein synthesis
 P las m id s : extrachromosomal
genetic elements
 Inclu s ions : sources of stored
energy, e,g volutin

14. Plasmid Plasmids
are
small ， circular/line ， extrachromosomal ， do
uble-stranded DNA molecules 。
capable of self-replication and contain genes
that confer some properties such as antibiotic
resistance ， virulence.
Inclusions Inclusions of
 are aggregates of
various compounds
Bacteria
that are normally
g ra nulo s involved in storing
energy reserves or
e building blocks for
the cell.
 accumilate when a
cell is grown in the
presence of excess
nutrients

15. Cell
membrane
• Site of biosynthesis of DNA, cell wall polymers and
membrane lipids. Selective permeability and transport of
solutes into cells
• Electron transport and oxidative phosphorylation
• Excretion of hydrolytic exoenzymes

16. Nucleus
• Lacking nuclear
membrane, absence
of nucleoli, hence
known as nucleic
material or nucleoid,
one to several per
bacterium.

17. Prokaryotic Cell Structure
 Glycocalyx - term to describe
substances that surround bacterial
cells
 1. Capsule
 if substance is organized and firmly
attached to cell wall
 2. Slime Layer
 if substance is unorganized and loosely
attached to cell wall
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18. Capsules and slime layers  Attachment
 Protection from phagocytic
engulfment.
 Resistance to drying.
 Depot for waste products.
 Reservoir for certain
nutrients.
 protection
 These are structures surrounding the outside of the cell envelope. They
usually consist of polysaccharide; however, in certain bacilli they are
composed of a polypeptide (polyglutamic acid). Capsules are often lost
during in vitro culture.
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19. Flagella:
Polar monotrichous Polar amphitrichous
Spirillium Lophotrichous
Pseudomonas
Spirillum
Peritrichous
Salmonella
SEM of peritrichous strain Proteous
Note: bacteria without flagella are called atrichous.
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20. In Gram-negative Bacteria
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21. In Gram-positive Bacteria
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22. Motility
• Flagella consist of a • Almost all Spiral bacteria are
number of proteins motile
• About 1/2 of Bacilli are
including flagellin motile
 Identification of • Almost all Cocci are non-
motile
Bacteria
• Bacteria move toward
 Pathogenesis attractive stimuli and away
from harmful substances
 Motility of bacteria
and waste products in the
process known as chemotaxis
.
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24. Pilli or fimbrae
• Filamentous appendages that are
shorter, straighter and more numerous
that flagella
• Conjugation pilli found in certain group
of bacteria.
• Used for genetic material transfer.
• The transfer process is called
conjugation.
• Antibiotic resistance transfer.
• Atatchment pilli, Help bacteria adhare
to the surfaces, such as cell surfaces
and interface of water and air.
• It helps in colonization and
pathogenicity.
• found mostly in Gram (-) Bacteria
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25. E. coli (pathogenic)
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26. Cell Wall
• Main structural component -
Peptidoglycan
• Peptidoglycan
– repeating dissacharide units
– polypeptides
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27. Gram-Positive
Gram- Negative
Peptidoglycan
Peptidoglycan
Cell Membrane Membrane
Outer Membrane Periplasm
Peptidoglycan
Cytoplasmic Peptidoglycan
membrane
Periplasmic
space
Another
cell
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28. Bacterial Cell Walls
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29. Gram (+) Cell Wall
• NAM N-acetylmuramic acid
• NAG N- acetylglucosamine
• tetrapeptide side chains
• pentaglycine crossbridges
• teichoic acid
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30. Gram (-) Cell Wall
• NAM
• NAG
• Tetrapeptide side chains
• pentaglycine
• 2nd Outer membrane
– Lipopolysaccharides (LPS)
• Lipid A
• O Antigen
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31. Functions of Cell Wall
• Maintaining the cell's characteristic shape- the rigid
wall compensates for the flexibility of the
phospholipid membrane and keeps the cell from
assuming a spherical shape
• Countering the effects of osmotic pressure
• Providing attachment sites for bacteriophages
• Providing a rigid platform for surface appendages-
flagella, fimbriae, and pili all emanate from the wall
and extend beyond it
• Play an essential role in cell division
• Be the sites of major antigenic determinants of the
cell surface 。
• Resistance of Antibiotics
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32. Cell Membrane (Plasma
Membrane)
• 2 structural component
– double layer of phospholipids
– proteins
• Fluid Mosaic Model
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33. cytoplasmic membrane
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35. Functions of Cell
Membrane
• 1. Selective barrier (selectively
permeable)
• 2. Secretes exoenzymes
– amylases
– lipases
– peptidases
– CAN NOT UNDERGO PHAGOCYTOSIS
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36. Functions of Cell
Membrane
• 3. E.T.S. is located here
• 4. Enzymes for cell wall synthesis
• 5. If photosynthesis, enzymes are
located on membranous structures
called thylakoids
• 6. Mesosomes - invagination of cell
membrane attached to DNA (Binary
Fission)?
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37. Endospores  Identification of
Bacteria
(spores)  Pathogenesis
 Resistance
• Dormant cell
• Resistant to adverse
conditions • Produced when starved
- high temperatures • Contain calcium dipicolinate
- organic solvents DPA, Dipicolinic acid
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Bacillus

38. Method
Microscope
• Light Microscope
• Electron Microscope
• Darkfield Microscope
• Phase Contrast
Microscope
• Fluorescence Microscope
• Confocal Microscope ）
Staining Methods
 Simple staining;
 Differential staining (Gram
stain, Acid-fast stain),
 Special staining( Negative stain,
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40. Gram Stain
• 1884 Hans Christian Gram
• most important stain used in
Bacteriology
• Divides all Bacteria into 2 groups:
– Gram (+)
– Gram (-)
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41. Gram Staining
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42. Results
• Gram (+) Purple
• Gram (-) Red
• Difference - due to
structure of cell wall
– Gram (+) Thick cell wall
– Gram (-) Thin cell wall
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