Presentation on Microbiology subject

1. 1
THE FIVE
KINGDOMS

2. 2
Introduction to Bacteria
2 TYPES OF BACTERIA:
•Bacteria
-Get food from an outside source
•Blue-green Bacteria
-Make their own food

3. 3
BACTERIA
Bacteria - small one celled monerans
Bacteria like a warm, dark, and moist
environment
They are found almost everywhere:
-water -air
-soil -food
-skin -inside the body
-on most objects

4. 4
Spiral:
spirilla
rod-shaped:
bacilli,
bacillus
Round:
cocci
3 Shapes of Bacteria
Bacteria are classified by shape into 3 groups:

5. 5
3 Shapes of Bacteria
Bacillus anthracis –
(bacillus)
Neisseria meningitidis
(coccus)
Leptospira interrogans –
(spirilla)

6. 6
7 Major Structures of a Bacteria Cell
•Capsule
•Cell wall
•Ribosomes
•Nucleoid
•Flagella
•Pili
•Cytoplasm

7. 7
Capsule
7 Major Structures of a Bacteria Cell
 keeps the cell
from drying out
and helps it
stick to food or
other cells

8. 8
Cell wall
7 Major Structures of a Bacteria Cell
Thick outer
covering that
maintains the
overall shape of
the bacterial
cell

9. 9
Ribosomes
7 Major Structures of a Bacteria Cell
 cell part where
proteins are made
 Ribosomes give
the cytoplasm of
bacteria a granular
appearance in
electron
micrographs

10. 10
Nucleoid
7 Major Structures of a Bacteria Cell
 a ring made
up of DNA

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Flagella
7 Major Structures of a Bacteria Cell
 a whip-like
tail that some
bacteria have
for locomotion

12. 12
7 Major Structures of a Bacteria Cell
Amimation of E.coli

13. 13
Pili
7 Major Structures of a Bacteria Cell
 hollow hair-like
structures made
of protein
allows bacteria
to attach to
other cells.
Pili-singular
Pilus-plural

14. 14
Cytoplasm
7 Major Structures of a Bacteria Cell
 clear jelly-like
material that
makes up most
of the cell

15. 15
•Binary Fission- the process of one organism
dividing into two organisms
•Fission is a type of asexual reproduction
Reproduction of Bacteria
How?...
The one main (circular)
chromosome makes a
copy of itself
Then it divides into two
•Asexual reproduction- reproduction of a
living thing from only one parent

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BINARY FISSION
Bacteria dividing Completed
Reproduction of Bacteria

17. 17
•The time of reproduction depends on how
desirable the conditions are
•Bacteria can rapidly reproduce themselves in
warm, dark, and moist conditions
•Some can reproduce every 20 minutes
(one bacteria could be an ancestor to
one million bacteria in six hours)
Reproduction of Bacteria

18. 18
Bacterial Cell &
Nucleiod DNA Ring
DNA replication
Cell wall synthesis
Cell separation

19. 19
Bacteria Survival
Endospore-
•a thick celled structure that forms inside
the cell
•they are the major cause of food poisoning
•they can withstand
boiling, freezing, and
extremely dry conditions
•it encloses all the
nuclear materials
and some cytoplasm
•allows the bacteria to survive for many years

20. 20
Bacillus subtilis
Endospore-the black section in the middle
highly resistant structures
can withstand radiation, UV light, and
boiling at 120oC for 15 minutes.
Bacteria Survival

21. 21
Bacteria Survival – Food sources
parasites – bacteria that feed on living things
saprophytes – use dead materials for food
(exclusively)
decomposers – get food from breaking down
dead matter into simple chemicals
important- because they send minerals
and other materials back into the soil so
other organisms can use them

22. 22
Harmful Bacteria
• some bacteria cause diseases
•Animals can pass diseases to humans
Communicable Disease –
Disease passed from one organism to another
This can happen in several ways:
•Air
•Touching clothing, food, silverware, or toothbrush
•Drinking water that contains bacteria

23. 23
Human tooth with accumulation of bacterial
plaque (smooth areas) and calcified tartar
(rough areas)
Harmful Bacteria

24. 24
Helpful Bacteria
•Decomposers help recycle nutrients into the
soil for other organisms to grow
•Bacteria grow in the stomach of a cow to
break down grass and hay
•Most are used to make antibiotics
•Some bacteria help make insulin
•Used to make industrial chemicals

25. 25
E.coli on small intestines
Helpful Bacteria

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•Used to treat sewage
Organic waste is consumed by the bacteria,
used as nutrients by the bacteria, and is no
longer present to produce odors, sludge,
pollution, or unsightly mess.
•foods like yogurt, cottage & Swiss cheese,
sour cream, buttermilk are made from bacteria
that grows in milk
Helpful Bacteria

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Controlling Bacteria
3 ways to control bacteria:
1) Canning- the process of sealing food in
airtight cans or jars after killing bacteria
•endospores are killed during this process
2) Pasteurization- process of heating milk
to kill harmful bacteria
3) Dehydration- removing water from food
•Bacteria can’t grow when H2O is removed
•example: uncooked noodles & cold cereal

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Controlling Bacteria
Antiseptic vs. Disinfectants
Antiseptic- chemicals that kill
bacteria on living things
•means – “against infection”
Examples: iodine, hydrogen peroxide,
alcohol, soap, mouthwash
Disinfectants- stronger chemicals that
destroy bacteria on objects or nonliving
things

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BLUE-GREEN BACTERIA
Autotrophs – make their own food
through photosynthesis
commonly grow on water and surfaces that
stay wet…such as rivers, creeks and dams
larger than most bacterial cells
Some live in salt water, snow, and acid
water of hot springs
food source for animals that live in the
water

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BLUE-GREEN BACTERIA
Blooms- occur when the
bacteria multiplies in great
numbers and form scum on
the top of the water
can be toxic to humans and animals

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