1. Kingdoms Archaebacteria and Eubacteria

2. KEY CONCEPT Kingdoms Eubacteria and Archaeabacteria are composed of single-celled prokaryotes.

3. Prokaryotes are widespread on Earth.
Prokaryotes can be grouped by their need for oxygen.
obligate aerobes are need oxygen
facultative aerobes can live with or without oxygen
obligate anaerobes are poisoned by oxygen

4. Domain Archaea, Kingdom Archaebacteria
Archaebacteria are typically obligate anaerobes.
Live in extremely harsh environments, ex.stomachs of cows, high salt concentrated areas such as the Dead Sea and in sulfur springs or deep sea vents.
Divided into 3 groups: methanogens (methane producers, halophiles (salt loving) and thermophiles (heat loving)
Come in a variety of shapes, similar to Eubacteria.
There is no peptidoglycan in their cell walls, and they contain entirely different lipids than Eubacteria.

5. they are among the earliest forms of life that appeared on earth.
ARCHAEA BACTERIA
Archaea are single celled organisms, classified as prokaryotes along with bacteria.
they are among the earliest forms of life that appeared on earth.
Archaea and Bacteria diverged from a common ancestor about 4 billion years ago.
Millions of years later, the ancestors of Eukaryotes split off from the Archaea.
Some (but not all) archaeans live in extremely adverse conditions and are often called extremophiles.

6. Classifying Archaebacteria
Thermophiles - live in extremely hot temperatures (some can survive 100 Celsius - like in a hydrothermal vent).
Halophiles - live in very salty, called hypersaline, environments
Halobacteria

7. Psycrophiles - live at unusually cold temperatures (some are found in Antarctic lakes). Most will die above 20 Celsius.
Acidophiles - many can exist at a pH of 0, all live in acidic environments.
Mud-Pool at Rotorua, NZ

8. Not all archaea are extremophiles, many live in normal temperatures and environments.
Most are methanogens which means they absorb CO2, N2, or H2S and gives off methane gas as a waste product the same way humans breathe in oxygen and breathe out carbon dioxide.
Archaea was originally thought to be just like bacteria, but are actually a much different and simpler form of life.
Archaea requires neither sunlight for photosynthesis as do plants, nor oxygen for respiration.

9. Archaebacteria
Archaebacteria are typically obligate anaerobes (cannot live in oxygen).
Come in a variety of shapes, similar to Eubacteria.
There is no peptidoglycan in their cell walls, and they contain entirely different lipids than Eubacteria.

10. Typical Eubacteria
Eubacteria and Archaebacteria are structurally similar but have different molecular characteristics.
flagellum
pili
plasmid
cell wall
chromosome
plasma membrance
This diagram shows the typical structure of a prokaryote. Archaea and bacteria look very similar, although they have important molecular differences.

11. Domain Bacteria, Kingdom Eubacteria
Eubacteria commonly come in three forms.
rod-shaped, called bacilli
spiral, called spirilla or spirochetes
spherical, called cocci
Lactobacilli: rod-shaped
Spirochaeta: spiral
Enterococci: spherical

12. Eubacteria groups (prefixes describe bacteria)
Diplo: two
Staphlo: cluster
Strepto: chain
Ex. Diplococcus
Ex. Staphlospirlli
Ex. Streptobacillus

13. Eubacteria
The amount of peptidoglycan within the cell wall can differ between Eubacteria: Gram negative has extra outer membrane, Gram positive cell wall just peptidoglycan
GRAM NEGATIVE
GRAM POSITIVE

14. stains polymer peptidoglycan
Gram staining identifies bacteria.
stains polymer peptidoglycan
gram-positive stains purple, more (large amounts) peptidoglycan
gram-negative stains pink, less (very little) peptidoglycan
Gram-negative bacteria have a thin layer of peptidoglycan and stain red.
Gram-positive bacteria have a thicker peptidoglycan layer and stain purple.

15. Bacterial Reproduction
ASEXUAL REPRODUCTION:
Since bacteria lack a nucleus, true mitosis and meiosis cannot occur.
Reproduction of bacteria in this case must occur through binary fission (splitting in two).
Bacteria contain a single chromosome which holds its genetic information
This single chromosome replicates, the bacteria grows, elongates and separates the 2 chromosomes.
The cell then builds a partition between the two chromosomes and the original cell splits into 2 smaller identical cells.
This method is very fast and a bacteria cell can divide in 20 minutes.
The two new bacteria both multiply again and so on, and so on. A single cell can become 30,000 cells in only 5 hours.

16. Sexual Reproduction - Bacteria have various strategies for survival.
Form of genetic recombination is conjugation.
transfer of genetic material (exchanging of genes) between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells
conjugation bridge
TEM; magnification 6000x

18. Other forms of genetic exchange
Transduction
Transduction: exchange of genes using a virus, does not require cell-to-cell contact like conjugation.
Transformation: endocytosis of free-floating DNA outside the cell.
Transformation

19. Bacteria survival Bacteria may survive by forming endospores.
Resistant to most cleaning agents and temperature changes
Creates double membrane around DNA to survive harsh conditions

20. Prokaryotes provide nutrients to humans and other animals.
Prokaryotes live in digestive systems of animals.
make vitamins
break down food
fill niches

21. Bacteria help ferment many foods.
yogurt, cheese
pickles, sauerkraut
soy sauce, vinegar

22. Prokaryotes play important roles in ecosystems.
Prokaryotes have many functions in ecosystems.
photosynthesize
recycle carbon, nitrogen, hydrogen, sulfur
fix nitrogen

23. Bioremediation uses prokaryotes to break down pollutants.
oil spills
biodegradable materials

24. Some bacteria cause disease.
Bacteria cause disease by one of two methods:
invading tissues
making toxins.
A toxin is a poison released by an organism.

25. immune system may be lowered
Normally harmless bacteria can become destructive.
immune system may be lowered

26. Ex. Tuberulosis (Mycobacterium tuberculosis)
Bacteria multiply in the lungs, killing WBCs
Host releases histamines which cause swelling

27. Ex. Staph poisoining (Staphylococcus aureus)
Food poisoning caused by mishandling of food
Infection of the skin

28. Ex. Botulism (Clostridium botulinum)
Improperly canned foods contaminated with endospores

29. Ex. Flesh eating bacteria (Streptococci)
Colonize tissue through cut or scrape

30. Antibiotics are used to fight bacterial disease.
Antibiotics may stop bacterial cell wall formation.
Their role is to interfere with the ability of the bacteria’s reproduction process.

31. Overuse of Antibiotics
Bacteria become resistant due to exposure
Underuse of Antibiotics
Kill the weak bacteria while stronger bacteria become resistant
Misuse of Antibiotics
Viruses cannot be treated with antibiotics, allowing normal bacteria to become resistant or killing them

32. Bacteria can evolve resistance to antibiotics.
1. Bacterium carries genes for antibiotic resistance on a plasmid.
2. Copy of the plasmid is transferred through conjugation.
3. Resistance is quickly spread through many bacteria.