1. What do these products have in common?
We need bacteria to make them!
2. 1) The Prokaryotes:
Eubacteria and Archaea
2) Protista
3) Fungi
4) Plants
5) Animals
6) ???
The Kingdoms of Life: A 6-part Series
3. Recall:
Prokaryotes are cells that have a nucleus and membrane-bound
organelles.
Which of the following is a prokaryote?
Prokaryote
Everything just floats
around in the cytoplasm
Eukaryote
Most things are wrapped-
up in membranes
4. Eubacteria
Bacteria are extremely important to humans.
Their uses include:
1) production of antibiotics to combat diseases
2) digestion, and production of vitamins K and B12
3) sewage treatment
(1)
(2)
(3)
5. Eubacteria
Bacteria are extremely important to humans.
Their uses include:
4) production of food
5) participation in biogeochemical cycles (ex. nitrogen fixing)
6) as a natural defense in and on our bodies
(4)
(5)
(6)
6. Common Bacteria Structure
The structure of a typical bacterium:
B
E
A – Flagellum
B – Nucleoid
C – Ribosome
D – Pilus
E – Plasmid
F – Capsule
G – Cell Wall
H – Plasma Membrane
I – Cytoplasm
7. Common Bacteria Structure
B
E
A – Flagellum (plural: flagella) – Used for motility.
B – Nucleoid – Densely packed loop of the bacterium's DNA.
C – Ribosome – Performs protein synthesis.
8. Common Bacteria Structure
D – Pilus (plural: pili) – Used to attach to surfaces and other cells.
E – Plasmid – Loop of DNA containing several genes.
F – Capsule – Thick slimy protective outer layer.
B
E
9. Common Bacteria Structure
G – Cell Wall – Rigid peptidoglycan layer provided shape and structure.
H – Plasma Membrane – Controls what goes in and out of the cell.
I – Cytoplasm – Fluid suspension containing the cell's contents.
B
E
10. Eubacteria
Bacteria are classified in several different ways, such as:
- cell shape
- reaction to staining
- cell arrangement
- metabolism
11. Bacteria Cell Shape
The 3 most common shapes of bacteria are:
Shape Image Advantages
Coccus (plural – cocci)
round shape
Resists drying-out.
Compact.
Bacillus (plural – bacilli)
rod shape
Larger surface area
increases nutrient
absorption.
Spirillum (plural – spirilli)
spiral shape
Can travel through fluids
with less resistance.
12. Bacteria Arrangement
Bacteria commonly associate in different shapes. Their names
are given prefixes based on how they attach together:
In pairs
Prefix: diplo-
In Chains
Prefix: strepto-
In clumps
Prefix: staphylo-
13. Bacteria Arrangement
For example, cocci that attach in these ways are given the
following names:
coccus diplococci steptococci staphylococci
14. Think. Pair. Share.
How would you name these bacteria?
streptobacilli staphylobacillistaphylococci
spirillumdiplobacillidiplospirilli
15. Bacteria Staining
The most common stain performed to identify bacteria is the
Gram stain – invented by Hans Christian Gram.
Gram staining uses crystal
violet dye that targets the
peptidoglycan in the
bacteria's cell wall, turning
it purple.
16. Bacteria Staining
After the crystal violet dye has been applied, safranin dye is
added to the slide to turn the remaining unstained cells pink.
17. Bacteria Staining
Gram-positive bacteria: have a thick peptidoglycan cell wall;
turn purple.
Gram-negative bacteria: have a thin or no peptidoglycan cell wall;
turn pink.
Gram +ve
bacteria Gram -ve
bacteria
18. Bacteria Metabolism
The metabolism of bacteria is described in a variety of ways:
1) food source
Bacteria can produce nutrients and energy from either:
i) inorganic chemicals - including carbon dioxide (CO2),
hydrogen sulphide (H2S), or methane (CH4)
20. Bacteria Metabolism
The metabolism of bacteria is described in 2 ways:
2) oxygen requirements
i) obligate aerobe – requires oxygen to survive
Bacteria grow best at the
top of the tube where
oxygen is most available.
21. Bacteria Metabolism
The metabolism of bacteria is described in 2 ways:
2) oxygen requirements
ii) obligate anaerobe – will not survive in the presence of oxygen
Bacteria grow best at the
bottom of the tube
where little oxygen is
present.
22. Bacteria Metabolism
The metabolism of bacteria is described in 2 ways:
2) oxygen requirements
iii) facultative aerobe – can survive with or without oxygen, but
prefers to have oxygen present
Bacteria prefer to grow at
the top of the tube, but
will survive anywhere.
23. Reproduction - Asexual
Bacteria can reproduce either sexually or asexually.
Asexual reproduction is called binary fission. Both daughter cells
are identical to the mother cell:
26. Reproduction - Sexual
Sexual reproduction occurs when a bacterium gains a new usable
piece of DNA.
Conjugation: Two cells attach to
each other and exchange DNA.
A conjugative pilus has connected
these two cells and a piece of
DNA can be passed through it.
30. Think. Pair. Share.
When conditions are
favourable and
unchanging, bacteria
prefer to perform binary
fission rather than sexual
reproduction.
Why?
VS
31. Think. Pair. Share.
Method Advantages Disadvantages
Asexual
Reproduction
- Faster
- Requires less energy
- No mate required
- Fast increase in population
may create competition for
resources.
- Daughter cells are identical
to parent. Lack of diversity is
vulnerable to disease.
Sexual
Reproduction
- Genetic diversity is
increased, making a more
resilient population.
- Slower
- Requires more energy
- Requires 2 cells
32. Endospores
If environmental conditions become unfavourable for growth
(such as lack of food), a bacterium may produce an endospore.
A tough shell forms around the
cell's nucleoid and some of the
cytoplasm.
33. Endospores
The bacterium becomes dormant and the tough endospore
can survive radiation, extreme heat or cold, harsh chemicals,
and lack of food or water.
Endospore
has formed.
Remainder of
the cell is left
to decay.
34. Endospores
Endospores can last thousands of years. When conditions
improve, they can revert back to active bacteria.
Endospores have been
found surviving on
ancient mummified
remains.
35. Sauerkraut explosion prompts quarantine
Last Updated: Saturday, September 11, 2010 | 2:58 PM PT
The Canadian Press
Twenty-four students and four staff members at a central B.C. high
school were briefly quarantined after a can of sauerkraut exploded
Friday in a food science class.
The fire department, a hazardous materials unit and RCMP were
called to Kelly Road Secondary School in Prince George at about 2
p.m. PT.
RCMP Const. Lesley Smith said school officials were concerned about
a possible botulism outbreak after the contents of a years-old can of
pickled cabbage splattered on students. Officials later determined
there was no cause for alarm.
The students briefly returned to their classes, then were dismissed
early.
36. Famous Bacteria
Bacteria are common pathogens (disease causing agents).
For example:
Clostridium botulinum
It produces a toxin that
paralyzes human
muscles. Ingestion can
be deadly. This disease
is called botulism.
C. botulinum is a
common cause of
preserved food
spoilage.
37. Famous Bacteria
Bacteria are common pathogens (disease causing agents).
For example:
Clostridium botulinum
The cosmetics industry
now uses this muscle-
paralyzing toxin to make
people look younger by
removing wrinkles.
38. Famous Bacteria
Bacteria are common pathogens (disease causing agents).
For example:
Escherichia Coli
E. coli is best known as one of the
human body's natural flora that
lives in the intestines.
Fecal-oral transmission of E. coli is
a common cause of disease.
39. Famous Bacteria
Bacteria are common pathogens (disease causing agents).
For example:
Escherichia Coli
E. coli can also produce toxins in
improperly preserved food or
untreated water, causing diarrhea,
cramps, or vomiting.
This "cronut burger" made news at the 2013 CNE for
making many people sick. The maple bacon jam
topping was not stored properly.
40. Famous Bacteria
Bacteria are common pathogens (disease causing agents).
For example:
Chlamydia trachomatis
Body cell
Chlamydia is a common sexually transmitted infection (STI).
Common symptoms are inflammation, burning sensations,
pregnancy complications, irregular discharge, and blindness.
The bacterium is a
parasitic cell that lives
inside of host cells.
41. Archaea
Three major reasons that Archaea are different from Bacteria are:
1) Most Archaea cell walls do not contain peptidoglycan.
2) Archaea live in extremely unfavourable conditions.
3) Archaea do not perform conjugation.
Archaea have been
found growing in
this highly acidic
mining run-off
42. Archaea
Because Archaea are able to survive extreme conditions, scientists
believe that they were among the first organisms on Earth.
43. Archaea
Archaea are classified based on the conditions that they live in:
Name Image Condition
Psychrophile Cold places (-10oC to -20oC) like the
poles and deep ocean water.
Methanogen Create methane in low-oxygen
environments. Common in swamps
bogs, and sewers.
Thermophile Hot places (70oC to 90oC) like
volcanoes and geothermal vents.
Halophile Highly saline (salty) places like salt
flats, salt water, and preserved
food.
Acidophile Acidic places (pH less than 2) such
as factory run-off and volcanoes.
