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Taxonomy – the 5 Kingdom
System
• One of the purposes of taxonomy is to
discover an organism’s PHYLOGENY – or
evolutionary history.
• We will be following organisms through the
“evolutionary family tree”, always keeping
the phylogeny of the different phyla in
mind.
Monerans:
Prokaryotic
Cells
• commonly
called
bacteria
Structure:
• Prokaryotic cells are not as complex as
eukaryotic cells. They do not have a nucleus and
they only have a few simple organelles
• They have a cell wall and a cell membrane,
cytoplasm and ribosomes. Their genetic material
(DNA or RNA) is circular. Some of the monerans
move around by means of a tail-like flagella
Comparison
Structure
of
Prokaryotic
Cells
Identifying Monerans:
• 1. Cell Shape
• a. Rod-Shaped
“Bacillus”
Bacillus – Electron micrograph
Bacilli ( gram negative)with
Flagella
Bacilli with Pilli
Comparative Size – RBC’s and
Bacteria
A – RBC
B – WBC
C - bacteria
b. Spherical – “Cocci”
• “Cocci”
Streptococcus
Sometimes, cocci
will form chains
c. Spiral Shaped “Spirillum”
Under our microscopes, it is
difficult to distinguish between
these 3 shapes.
Under TEM
Under our Microscopes
2. Cell Walls
• Bacteria cell walls can be
stained by either
CRYSTAL VIOLET
(purple) or SAFRANINE
(red). These stains are
called GRAM stains. If
the bacterium picks up
the purple stain, it is
considered GRAM
POSITIVE. If the
bacterium picks stains
red, it is considered
GRAM NEGATIVE.
Gram Staining
Overview
• 1. Wash slide
• 2. “Fix” bacteria to slide
• 3. Flood with Crystal
Violet
• 4. Leave 1 minute
• 5. Rinse with water
• 6. Flood with gram’s
iodine
• 7. Decolorize with Ethanol
• (gram (-) loose color)
• 8. Counterstain with
Safranin – 30 seconds
• 9. Rinse with water, air
dry
3. Bacterial
Movement
• We can also
distinguish between
different types of
bacteria by how they
get around.
• Types of movement
include:
Whipping it’s flagella,
gliding along a slime
layer, slithering along
like a snake and
spiralling forward like
a cork-screw.
Diversity of Bacteria
• Some are autotrophic
– either phototrophic
or chemotrophic.
(chemotrophic use
inorganic molecules
like hydrogen
sulphides, nitrites or
iron to make energy.
They live in harsh
environments)
Chemosynthetic Ecosystems
• In a normal marine ecosystem, the organisms
found at the bottom of the food chain are
seagrass and phytoplankton, which produce
energy through photosynthesis (a
photosynthetic ecosystem). In environments
rich in methane and sulfides, one type of food
chain relies on chemosynthetic bacteria as
basic producers. These include sulfur-oxidizing
bacteria, methane-oxidizing bacteria, and
sulfide-reducing bacteria. Such an environment
is referred to as a chemosynthetic ecosystem.
• A special characteristic of a
chemosynthetic ecosystem is its large
biomass, despite its location in the deep
sea.
Diversity
• Some are
HETEROTROPHIC
(like humans are).
This means that they
ingest organic
molecules, and digest
them to release the
energy.
Diversity
• Some are OBLIGATE AEROBES (like us); they
would die without oxygen.
Diversity
• Others are
OBLIGATE
ANAEROBES; they
would die in the
presence of oxygen.
•  (example of this is
C. botulinum – causes
botulism)
• Finally, some
bacteria are
FACULTATIVE
ANAEROBES;
these bacteria can
live with or
without oxygen.
Bacterial
Reproduction
• 1. Binary Fission. (a
form of asexual
reproduction)
2. Conjugation
• (a form of sexual
reproduction).
• A protein bridge is
formed between the
two bacteria through
which the donor
bacterium sends part
of it’s genetic material
to the recipient.
3. Spore
Formation
• When conditions are
unfavourable, the
bacterium might create
a thick, internal wall
around it’s genetic
material and some
cytoplasm. This
ENDOSPORE can
remain dormant for an
indeterminate amount
of time, waiting for
more favourable
conditions again
The 4 Phyla of MONERA
• 1. Eubacteria:
• The “true” bacteria
• This is the largest
group of bacteria (in
numbers, not size!)
2. Cyanobacteria
• The “blue-green
algae”. (this is a misnomer – algae are
EUKARYOTIC cells).
Thes are autotrophic,
but us a more
primitive form of
photosynthesis than
found in higher plants.
3. Archaebacteria
• These APPEAR
to be the most
primitive,
ancient forms of
bacteria.
However, on
closer
examination,
they are more
closely related
to eukaryotic
cells than they
are to other
prokaryotic
cells.
• Archaebacteria live in
the HARSHEST of
conditions – high
temperatures, high
salinity (halophilic),
oxygen free
(anaerobic),
chemosynthetic, etc.
Archaebacteria –
A halobacteria
(Lives in high
salinity)
•
they color the salt flats
of desert playas and
evaporation ponds a
pinkish-red. This is in
Owens Lake CA.
Owens Lake was once
a vast blue lake, before
it was drained (by
diverting Owens River)
to provide LA with
water. Today it is a
pinkish-red, dry lake
bed teaming with saltloving archaebacteria.
A drop of brine
contains millions of
tiny bacilli swimming
among crystals of
NaCl.
• Archaebact. At
high
temperatures.
Yellowstone
National Park

 High
Salinity - Great
Salt Lake, Utah
(aerial view)
4. Prochlorobacteria
• These bacteria have
chlorophyll a and
chlorophyll b which
makes them very
similar to chloroplasts
found in higher plants.
Host – a tunicate
Bacteria in Our World:
• Food Production –
bacteria are used to
produce cheese,
yogurt, sour cream,
vinegar, etc.
Lactobacillus acidiphilus and
Streptococcus thermophilis (1000X)
The bacteria that make Yogurt
Industry:
• Bacteria can digest
some petroleum,
remove waste products
from water, mine
minerals from the
ground and can
produce some drugs
(like insulin).
•  Thiobacillus
ferrooxidans extracts
copper from low-grade
copper ore
Oil-Spill Treatment
• Species from all of the
4 other Kingdoms are
dependent on bacteria
in symbiotic
relationships with
different bacteria
• Ex: lichen:
bacteria and fungus
• Termites, are composite
organisms. The protist at
left is just "one" of hundreds
of thousands of microbes
that live symbiotically
within the termites digestive
tract, and it is actually
composed of at least 5
different organisms. The
"hair-like" projections are
actually several different
species of spirochete and
bacillus bacteria that seem
to function in
movement. Still other
bacteria live within the
protist cell, releasing energy
from the food that it absorbs
while other bacteria
produce the enzymes
• Some bacteria are
saprophytes (organisms
that obatin their energy
and nutrients from
“once-living” material).
We depend on their
ability to decompose
organisms after they
have died. They are also
responsible for the
decomposition of our
sewage.
• Some plants are
dependent on bacteria
for “nitrogen fixation”
– they are able to trap
the nitrogen from the
air into ammonia
(NH3) and nitrate
(NO3-). Plants can use
these forms of
nitrogen, but are
unable to use nitrogen
from the air
• ** there are far more beneficial bacteria in
this world than pathogenic bacteria***
• Pathogenic bacteria
cause us grief in two
ways: damaging cells
and releasing toxins
(staphylcoccus
infection - impetigo
• We have
learned many
techniques to
sterilize our
environments
and our foods
by using high
temperatures
and
disinfectants.
• Medicine is able to
prevent bacterial
infections using
vaccinations.
• We also have antibiotics
– drugs that kill bacteria
specifically.