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BACTERIA!!
(Formerly Kingdom Monera)
EUKARYOTES
PROKARYOTES
EUBACTERIA
ARCHAEABACTERIA
Bacteria Cell Structures
Prokaryotes
(Bacteria)
 Eubacter
"True" bacteria
– human pathogens
– clinical or environmental
– one kingdom
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Archaea
– Environmental organisms
– second kingdom
Bacteria are of
immense importance
because of their
rapid growth,
reproduction, and
mutation rates, as
well as, their ability
to exist under
adverse conditions.
 The oldest fossils
known, nearly 3.5
billion years old,
are fossils of bacterialike organisms.
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More Characteristics of Bacterial
Cells
1. They are prokaryotes (no membrane bound
nucleus or organelles)
2. Bacterial cells have a single chromosome.
3. Most bacteria reproduce by binary fission.
4. Bacteria show great metabolic diversity.
5. Found as single cells or in groups of two or
more (called a colony)
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Bacteria can be autotrophs or hetertrophs.
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Those that are classified as autotrophs are
either photosynthetic, obtaining energy
from sunlight or chemosynthetic,
breaking down inorganic substances for
energy .
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Bacteria classified as
heterotrophs derive
energy from breaking
down complex
organic compounds in
the environment.
This includes
saprobes, bacteria
that feed on
decaying material
and organic
wastes, as well as
those that live as
parasites, absorbing
nutrients from living
organisms.
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Depending on the
species, bacteria can
be aerobic which
means they require
oxygen to live
or
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anaerobic which
means oxygen is
deadly to them.
Green patches are green sulfur
bacteria. The rust patches are
colonies of purple non sulfur
bacteria. The red patches are purple
sulfur bacteria.
Archaebacteria
Kingdom Archaebacteria
First discovered in extreme
environments
 Methanogens: Harvest energy by
converting H2 and CO2 into methane gas
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– Anaerobic, live in intestinal tracts
Extreme halophiles: Salt loving, live in
Great Salt Lake, and Dead sea.
 Thermoacidophiles: Live in acid
environments and high temps.
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– Hot Springs, volcanic vents
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Eubacteria
Cyanobacteria
This is a group of bacteria
that includes some that are
single cells and some that
are chains of cells. You may
have seen them as "green
slime" in your aquarium or in
a pond.
Cyanobacteria can do
"modern photosynthesis",
which is the kind that makes
oxygen from water. All plants
do this kind of
photosynthesis and inherited
the ability from the
cyanobacteria.
Cyanobacteria were the first organisms on Earth to
do modern photosynthesis and they made the first
oxygen in the Earth's atmosphere.
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Bacteria are often
maligned as the
causes of human and
animal disease.
However, certain
bacteria, the
actinomycetes,
produce antibiotics
such as streptomycin
and nocardicin.
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Other Bacteria live symbiotically in the
guts of animals or elsewhere in their
bodies.

For example, bacteria in your gut produce
vitamin K which is essential to blood clot
formation.

Still other Bacteria live
on the roots of certain
plants, converting
nitrogen into a usable
form.

Bacteria put the tang
in yogurt and the sour
in sourdough bread.

Saprobes help to
break down dead
organic matter.

Bacteria make up the
base of the food web
in many
environments.
Streptococcus thermophilus in yogurt
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Bacteria are prokaryotic and unicellular.

Bacteria have cell walls.

Bacteria have circular DNA called plasmids
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Bacteria can be anaerobes or aerobes.

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Bacteria are heterotrophs or autotrophs.
Bacteria are awesome!

Bacteria can reproduce sexually by conjugation or
asexually by binary fission.
Binary Fission
Endospore

Bacteria can survive
unfavorable
conditions by
producing an
endospore.
Shapes of Bacteria
Kingdom Eubacteria

Can have one of three basic shapes:
1. Bacilli – rod-shaped
2. Spirilla – spiral-shaped
3. Cocci – sphere-shaped
Streptococci – in chains
Staphylococci – grape-like
clusters
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Name the Type
Name the Type
Name the Type
Name the Type
Name the Type
Penicillin, an antibiotic, comes from molds of the
genus Penicillium Notice the area of inhibition
around the Penicillium.

Penicillin kills bacteria by making holes in their
cell walls. Unfortunately, many bacteria have
developed resistance to this antibiotic.
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The Gram stain, which divides most
clinically significant bacteria into two main
groups, is the first step in bacterial
identification.

Bacteria stained purple are Gram + - their
cell walls have thick petidoglycan and
teichoic acid.

Bacteria stained pink are Gram – their cell
walls have have thin peptidoglycan and
lipopolysaccharides with no teichoic acid.
In Gram-positive bacteria, the purple crystal violet stain is
trapped by the layer of peptidoglycan which forms the outer
layer of the cell. In Gram-negative bacteria, the outer
membrane of lipopolysaccharides prevents the stain from
reaching the peptidoglycan layer. The outer membrane is then
permeabilized by acetone treatment, and the pink safranin
counterstain is trapped by the peptidoglycan layer.
Is this gram stain positive or negative?
Identify the bacteria.
Is this gram stain positive or negative?
Identify the bacteria.
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Gram staining tests the bacterial cell wall's
ability to retain crystal violet dye during solvent
treatment.
Safranin is added as a mordant to form the
crystal violet/safranin complex in order to render
the dye impossible to remove.
Ethyl-alcohol solvent acts as a decolorizer and
dissolves the lipid layer from gram-negative
cells. This enhances leaching of the primary
stain from the cells into the surrounding solvent.
Ethyl-alcohol will dehydrate the thicker grampositive cell walls, closing the pores as the cell
wall shrinks.
For this reason, the diffusion of the crystal
violet-safranin staining is inhibited, so the
bacteria remain stained.
Bacteria and Disease
Disease
Pathogen
Areas
affected
Mode of
transmission
Botulism
Clostridium botulinum
Nerves
Improperly preserved
food
Cholera
Vibrio cholerae
Intestine
Contaminated water
Dental Caries
Streptococcus mutans,
sanguis, salivarius
Teeth
Environment to mouth
Gonorrhea
Neisseria gonorrhoeae
Urethra,
fallopian
Sexual contact
Lyme disease
Berrelia burgdorferi
Skin, joints
Tick bite
Rocky
Mountain SF
Rickettsia recketsii
Blood, skin
Tick bite
Salmonella
Salmonella
Intestine
Contaminated food,
water
Strep throat
Streptococcus pyogenes
URT, blood,
skin
Sneezes, coughs, etc.
Tetanus
Costridium tetani
Nerves
Contaminated wounds
Tuberculosis
Mycobacterium tuberculosis
Lung, bones coughs
STREP THROAT
Strep Throat
SALMONELLA
LYME DISEASE
BOTULISM
Leprosy is a
bacterial
infection
that
decreases
blood flow to
the
extremities
resulting in
the
deterioration
of toes, ears,
the nose and
the fingers.
Helicobacter
pylori
is the
pathogenic
bacteria
that can
causes ulcers
Common Antibiotics
Antibiotic
Mechanism
Target bacteria
Penicillin
Inhibits cell wall synthesis
Gram Positive
Ampicillin
Inhibits cell wall synthesis
Broad spectrum
Bacitracin
Inhibits cell wall synthesis
Gram Positive – Skin
Ointment
Cephalosporin
Inhibits cell wall synthesis
Gram Positive
Tetracycline
Inhibits Protein Synthesis
Broad spectrum
Streptomycin
Inhibits Protein Synthesis
Gram Neg. tuberculosis
Sulfa drug
Inhibits cell metabolism
Bacterial meningitis, UTI
Rifampin
Inhibits RNA synthesis
Gram Pos., some Neg.
Quinolines
Inhibits DNA Synthesis
UTI
Importance of Bacteria
Human disease (strep, food poisoning,
wound infections, etc.)
 Disease in animals and plants
 Food spoilage
 HOWEVER, only a small % of bacterial
species are actually harmful
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Importance of Bacteria
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Decomposers
Produce vitamins in the human intestine
Vinegar, yogurt and cheese are made using bacteria
Some bacteria produce antibiotics
Fuel can be produced (methane) from metabolized
wastes from some
Natural pesticides: infect caterpillars that destroy crops.
Help produce Vitamin K in our intestines (used for blood
clotting)
Some bacteria (the flavobacterium) eat the poison
pentoclorophenol, found in wood preservative. Once the
toxin is removed the microbe dies.
Text Assignment
Read pages 471 to 477 and complete the
following:
 Q1-6 on page 477
Review your PPT notes
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