Transcript Archaebacteria - Nutley Public Schools

Archaebacteria and Eubacteria
Important Features
-all are prokaryotes
-all have plasmids (small circular
packages of DNA)
-most have peptidoglycan in their
cell walls
-flagella are made with a globular
protein called flagellin
Cytosol
Granules
(Small chunks of food)
Locomotion (Methods of Movement)
Bacterial
Flagellum
Pili- short, thin appendages
Bacteria
E. coli
E. coli
Nutrition-DO NOT NEED TO
COPY
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
Autotrophs- manufacture organic compounds
– Photoautotrophs- use light energy & CO2
– Chemoautotrophs-use inorganic substances
like H2S, NH3, and other nitrogen compounds
Heterotrophs- obtain energy by consuming organic
compounds
– parasites- get energy from living organisms
– saprobes (saprophytes)- get energy from
dead, decaying matter; also called
decomposers
Oxygen Preferences
obligate
aerobes- must have
oxygen
obligate anaerobes- cannot live in
oxygen
facultative anaerobes- can grow
with or without oxygen
2 Bacteria Kingdoms
Kingdom
Archaebacteria - are ancient
bacteria that live in extreme
environments
Kingdom Eubacteria - are generally
referred to as bacteria or germs, and
are considered more recent. Most types
of bacteria belong in this kingdom.
The Archaebacteria:
do
not have peptidoglycan in
their cell walls
have ribosomes similar to
eukaryotes
have unique lipids in their
plasma (cell) membranes
The Archaebacteria also:
have some genes that resemble
eukaryotic genes
usually are not pathogenic (they
don’t usually make us sick!)
live in extreme environments:
–high concentrations of salt
–extremes of pH and temperature
3 Archaebacterial Groups
Methanogens-turn H2 and CO2 into
methane
Halophiles-salt
Thermoacidophiles = live in
extremely hot, acid environments
Methanogens
anaerobic
bacteria that get energy
by turning H2 and CO2 into
methane
live in mud, swamps, and the guts
of cows, humans, termites and
other animals
Halophiles
are
organisms that live in environments
with extremely high salt concentrations
– some extreme halophiles can live in
solutions of 35 % salt. (seawater is only
3% salt!)
halophile means “salt loving”
most halophiles are aerobic and
heterotrophic
Diversity of Halophilic Organisms
halophiles
are found in salt lakes, salt
marshes, subterranean salt deposits,
dry soils, salted meats
the Red Sea was named after the
halobacterium that turns the water red
during massive blooms.
Halophile
Environments
Owens Lake,
Great Salt Lake,
coastal splash zones,
Dead Sea
Thermoacidophiles
 Like
temperature and pH extremes
– Hot = up to 3740ºF
– Cold = down to 34ºF
– Acid = pH 2
– Basic = pH 9
 they are chemoautotrophs
the
first Extremophile was found about
30 years ago
Extreme Temperatures
- High temperature = 60-800C
– Thermal vents and hot springs
– May go hand in hand with chemical extremes
 Psychrophiles - Low temperature
– Arctic and Antarctic
»Most rely on photosynthesis
 Thermophiles
Thermophile
Environments
Hydrothermal Vents in
the ocean, and
Obsidian Pool in
Yellowstone
National Park
Alan Hills
Ice Field:
Antarctica
Psychrophile Environments
Chemical Extremes
Acidophiles
- Acidic
– Again thermal vents and some hot springs
Alkaliphiles
- Alkaline
– Soda lakes in Africa and western U.S.
Halophiles
- Highly Salty
– Natural salt lakes and manmade pools
– Sometimes occurs with extreme alkalinity
Acidophile Environments
Alkaliphile Environments
e.g. Mono Lake
alkaline soda lake,
pH 9, salinity 8%
Examples of Unusual Habitats
 The
bacterium pseudomonas was found
living on a desert plant in the Negev
Desert. The plant secretes salt through
salt glands on its leaves.
 Bacillus was found in the nasal cavities of
desert iguanas. These iguanas have salt
glands in their nasal cavities that secrete
KCl brine during osmotic stress.
IDENTIFICATION of BACTERIA – 3
MAIN SHAPES
Baccili
Cocci
Spirillum
Identification – cell walls
 There
is a method used to tell apart two
types of cell walls in eubacteria, called
Gram staining.
 Gram-positive bacteria stain violet
– These bacteria have 1 cell membrane
surrounded by a thick peptidoglycan wall
which holds the color well.
 Gram-negative
bacteria stain pink
– These bacteria have a thin peptidoglycan wall
between 2 membranes. The wall is too thin to
hold the color as well.
Bacterial diseases
 Bacteria
produce disease in 1 of 2 ways:
– Damage cells and tissues of the organisms it is
infecting by breaking down the cells for food.
Example- tuberculosis
OR
– Releasing toxins that will travel throughout the
body, which interfere with the normal activity
of the infected organisms cells. Example- strep
throat
Preventing bacterial disease
 Vaccines-
injection of a weakened form of
a pathogen that prepares the body to
produce immunity to the pathogen
 Antibiotics-
given after infection, they
block the growth and reproduction of
bacteria
Controlling bacteria
 How
can we control the presence of
bacteria?
–
–
–
–
Sterilization with heat
Disinfectants
How we store food
How we process food
They aren’t all bad!
 We
need bacteria for:
– Decomposition- help recycle materials in
nature
– Nitrogen fixation- bacteria convert nitrogen gas
to a form of nitrogen that the plants can use
– Good bacteria in foods
– E. coli in our intestines