1. The Kingdoms Bacteria

2. Diversity of Prokaryotes
Recall that prokaryotes are single celled organisms without a nucleus or membrane bound organelles
They are classified into two kingdoms
Archaebacteria and Eubacteria

3. Archaebacteria-The extremists
1. There are three types of archaebacteria that live mainly in extreme environments that contain little or no free oxygen available
Methanogens
Halophytes
Sulfur bacteria

4. Methanogens
Methanogens live in oxygen free environments and produces methane
They live in marshes, lake sediments, and the digestive tracts of some mammals (like cows)
They are also found at sewage treatment plants where they are important in the break down of wastes

5. Halophytes 3. A second type of archaebacterium that lives
only in water with high concentrations of salt
Dead Sea

6. 4. Sulfur bacteria
A third type lives in the hot, acidic waters of sulfur springs (like in Yellowstone)
Some also live in deep cracks in the ocean floor…there they are autotrophic producers (chemoautotrophs)

7. 5. Eubacteria – the heterotrophs
Eubacteria are the other type of prokaryotes…they live in more hospitable environments
Heterotrophic eubacteria live almost everywhere and use organic molecules as their food source

8. 6. Eubacteria – the heterotrophs
Some bacterial heterotrophs are parasitic
Others are saprophytes-organisms that feed on dead organisms or organic wastes

9. 7. Eubacteria – photosynthetic autotrophs
A second type of eubacterium is the photosynthetic autotroph
These eubacteria live in places with sunlight because they need light to make the organic molecules that are their food
Cyanobacteria

10. 8. Eubacteria – chemosynthetic autotrophs
A third type of eubacterium is the chemosynthetic autotroph
They make their own food without sunlight
They break down and release energy from inorganic nitrogen and sulfur compounds (biogeochemical cycling)

11. 9. What is a bacterium?
A bacterium consists of a very small prokaryotic cell
Although small they have all of the structures that they need to survive

12. The structure of bacteria
Capsule
Cell Wall
Chromosome
Flagellum
Plasmid
Pilus
Plasma membrane
Cytoplasm
Ribosome
Chromosome
Flagellum
Cell Membrane
Cell Wall
Gelatinlike
capsule

13. 10. Antibiotics
In 1928, Alexander Fleming accidentally discovered penicillin – the first antibiotic that is used to kill bacteria
Penicillin interferes with the bacteria’s ability to produce its cell wall
The holes in the cell wall then allow water to enter the cell and it will rupture
penicillin

15. 11. Identifying bacteria
There are three ways that you can use to identify bacteria without chemical/biological tests
Gram stain
Shape
Arrangement

16. 12. Gram staining
After staining, Gram positive bacteria are purple and Gram negative bacteria are pink
Gram-positive bacteria
Gram-negative bacteria

17. 13. Shape
The three most common shapes are spheres, called coccus; rods, called bacillus; and spirals, called spirillum

18. 14. Arrangement Diplo–is a prefix that refers to a
paired arrangement of cell growth.
The prefix staphylo–describes an arrangement of cells that resemble grapes or clusters
Strepto–is a prefix that refers to an
arrangement of chains of cells.

19. 15. Bacterial reproduction
Bacteria reproduce asexually through a process known as binary fission
Under ideal conditions, some bacteria could reproduce every 20 minutes…why don’t they?

20. 16. More bacterial reproduction
Sometimes bacteria undergo a form of “sexual” reproduction called conjugation
During conjugation one bacteria transfers all or part of its chromosome to another using the pilus
The spread of antibiotic resistance is a result of conjugation

22. 17.The importance of bacteria
Compared to beneficial bacteria, there are relatively few bacteria that cause disease
In contrast, many bacteria allow us to survive…here are some of the things that they do…

23. 18. Bacterial Jobs Nitrogen fixation Recycling nutrients
Production of foods (pickles, cheese, yogurt, Sauerkraut, cured meats)
Help produce vitamins and enzymes to digest food
Produce antibiotics that kill bacteria that cause disease (streptomycin, erythromycin, bacitracin, and neomycin )

24. 19. Some bacterial diseases
Bacteria can harm you in two ways: by interfering with normal body function or by producing toxins that poison the body
Diseases Caused by Bacteria
Disease
Transmission
Symptoms
Treatment
Strep throat
(Streptococcus)
Inhale or
ingest through
mouth
Fever, sore throat,
swollen neck glands
Antibiotic
Tuberculosis
Inhale
Fatigue, fever, night
sweats, cough, weight
loss, chest pain
Tetanus
Puncture
wound
Stiff jaw, muscle
spasms, paralysis
Open and clean wound,
antibiotic; give antitoxin
Lyme disease
Bite of
infected tick
Rash at site of bite,
chills, body aches,
joint swelling
Dental
cavities (caries)
Bacteria
in mouth
Destruction of tooth
enamel, toothache
Remove and fill the
destroyed area of tooth
Diptheria
close contact
Sore throat, fever,
heart or breathing
failure
Vaccination to prevent, antibiotics