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Bacteria
Origins - Three Domain Classification
EU
PROKARYOTES
I. Origins of Bacteria
Prokaryotes
Archaebacteria
Eubacteria
A. Prokaryotes =
1. Kingdom Eubacteria
2. Kingdom Archaebacteria
3. Prokaryote =
does not have a nucleus
I. Origins
B. 3.5 billion years ago
C. FIRST LIFE FORMS were:
Archaebacteria, or ancient bacteria
(how do we know this?)
early Earth atmosphere had almost no O2
D. Eubacteria is true bacteria
(Eu = true)
Æ Eukaryote = true nucleus
II. Archaebacteria
A. General Info.
1. EXTREME ! Primitive bacteria
2. Live in extreme or harsh environments
B. Three kinds of Archaebacteria:
1. Halophiles
= live in very basic or salty environments
E.g. Great Salt lake, Dead Sea
2. Methanogens
–Anaerobic
(don’t
need O2)
–Make
methane
gas (CH4)
Swamp
3. Thermophiles
– live in hot or acidic environments (~pH 1-4)
• Near undersea volcanic vents
• Sulphur Springs
• Hot springs in Yellowstone National Park
III. Eubacteria
A. General
1. Ubiquitous = they exist everywhere,
most of the bacti. we know
2. Harmful – pathogenic (they cause
disease)
3. Helpful – they have a variety of uses
4. Odd means of getting nutrients
• Chemo – autotrophic (“eat”
chemicals)
• Some “eat” NH3 (ammonia)
• Some “eat” H2S (hydrogen sulfide)
» Sulfide-eating bacteria
Helpful Bacteria
1. Food & Drink Production
Fermentation (drinks)
– Wine, beer
Dairy products
– Cheese, sour cream,
yogurt, sourdough,
Other
-Pickles, vinegar,
sauerkraut
Helpful Bacteria
2. Sewage Decomposition
Bacteria break down the organic matter
Helpful Bacteria
3. Water Treatment
Helpful Bacteria
¿ Where is most of the Nitrogen
found on planet Earth?
In the atmosphere
¿ Where do plants need it to be?
In the soil
4. Nitrogen Fixation in roots
– Helps plants take up H2O and
nutrients from soil
Helpful Bacteria
5. Bio-mineralization in Mining
– Bacteria concentrate desired elements from
ore
Ralstonia metallidurans,
is capable of
– E.g. Au (gold)
precipitating dissolved
gold.
Cu (copper)
Helpful Bacteria
6. Bioremediation
– Microbes can
help repair
damaged
ecosystems
– Pseudomonas
, a common
type of oil
eating
bacteria, is
used around
the world to
help clean up
oil spills.
Helpful Bacteria
7. Human
Recreation
= Artificial SnowMaking
– Bacteria allow
H2O to form
ice crystals
Bacterial Classification
1. Shape and Groupings
2. Cell wall composition
3. Environment
4. DNA Sequences
Bacterial Cell
Bacterial Structure
‰
Cell Wall
Prevents cell from rupturing
¾ Composition of cell wall helps to identify
bacteria
¾
Bacterial Structure
‰
Cell Membrane
F(x) = support & protect
¾ Differentially permeable
¾
‰
Cytoplasm
¾
Contains organelles (non-membranous)
Bacterial Structure
‰ Genetic
Material
¾ Single,
circular chromosome
¾ Plasmid = extra chromosome that can
replicate separately from the main
chromosome
•
•
Use as vector for biological engineering
Can pass genes for antibiotic resistance to
other bacteria (sometimes resistance to
several antibiotics @ one time)10/
Bacterial Structure
‰
Ribosomes
¾
F(x) is to synthesize proteins
Bacterial Structure
‰
Capsule (Slime Layer)
¾
¾
viscous coating outside of bacteria cell wall
F(x)s:
• Protection
• × bacteria’s pathogenicity (or ability to cause disease)
• Protects bacteria from the Immune System (WBC’s)
Bacterial Structure
‰ Other
structures (Appendages)
¾ Flagella
•
•
F(x) = locomotion
Cell can have one, two, or many
¾ Pili
•
(protein appendage)
(hair-like extensions)
F(x)s = attachment to host and transfer of
genetic material
¾ Fimbriae
•
(shorter than pili)
F(x) = adhesion to surfaces
Flagella
Bacterial Shapes
™
A. Typical
1.
Coccus/Cocci =
spherical or round
2.
Bacillus/Bacilli =
rod-shaped
3.
Spirillum/Spirilli
= spiral-shaped
Bacterial Shapes
Bacterial Groupings
ƒ Groups determined by the plane
in which the cell divides
Bacterial
Groupings
– 1 plane =
• diplo- (pair)
• strepto- (chain)
– 2 planes =
• tetrad (packet of 4)
– Several planes @
random =
• staphylo(grape-like clusters)
Identify shapes & groupings
Bacterial Shapes
B. Atypical
1. Pleomorphic
Variable in shape and size
Eg. Stella (stars)
Eg. Arcula (cubes)
2. Mycoplasmas
Lack rigid cell walls
Can change shape
GRAM STAINING
• History & Definitions
– Developed by Hans Christian
Gram in 1884
– Helps to identify different types
of bacteria (a differential stain)
– Stain uses differences in cell wall
composition to differentiate between bacteria
– Can help determine which type of antibiotics
will be most effective against a particular
bacteria
Gram Positive Cells
• Stain purple
– Has thick
peptidoglycan layer
• More susceptible to Penicillin
Thick layer of peptidoglycan
Gram Positive
POSITIVELY PURPLE!!!
Gram Negative
Thin layer of peptidoglycan
Gram Negative
• Stain pink/light red
– A thin layer of peptidoglycan
(space)
• Less susceptible to Penicillin than
gram positive
Penicillin (a fungus)
• Antibiotic inhibits synthesis of
peptidoglycan;
used on actively growing
organisms.
–Gram (+) cells Æ Penicillin
works
–Gram (-) cells Æ Pencillin
doesn’t work so well
Overview of Staining
Why do we stain?
•To better view a cell’s structure.
Gram Staining Procedure
Steps (abbreviated):
1) Add primary (1o) stain – Crystal Violet
2) Add mordant to cells – Iodine
3) Add decolorizer to cells – Alcohol
4) Add secondary (2o) stain - Safranin
Gram Staining Steps
Bibliography
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Thanks to Jordan Sonneberg for the start of this ppt!
Yellowstone sciences.unlv.edu/.../Pages/episode2.htm Retrieved 11/12/08
Yellowstone serc.carleton.edu/microbelife/research_methods/ 11/212/08
Swamp Protegeu http://photos.mongabay.com/pt/Swamp_Shaded.htm Retrieved 11/12/08
Image of ribosomes sciences.unlv.edu/.../Pages/episode2.htm Retrieved 11/27/07
Image of Bacterial cell wall pbdb.itan.kyoto-u.ac.jp/saikin-e.html Retrieved 11/27/07
Map of Great Salt Lake ut.water.usgs.gov/greatsaltlake/index.html Retrieved 11/27/07
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Image of Dead Sea www.pjsoaps.com/1DeadSeaSpa.html Retrieved 11/27/07
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Pickles http://www.getrichslowly.org/images/pickles1.jpg Retrieved 11/12/08
Yogurt http://wikigreenfrost.pbwiki.com/Helpful+or+Harmful Retrieved 11/12/08
Sewage treatment plant
http://www.biosolids.com.au/uploads/images/Sewage%20treatment%20process%20v2a.jpg Retrieved 11/12/08
Water Treatment http://www.saskatoon.ca/org/water_treatment/wastewater_treatment/WWTP1a.jpg Retrieved
11/12/08
Sauerkraut http://www.recipeathome.info/pictures/1171431564SAUERKRAUT.jpg Retrieved 11/12/08
Nitrogen-fixing bacteria http://telstar.ote.cmu.edu/environ/m3/s4/graphics/embedded/nitronodules.gif
Retrieved 11/12/08
Biomineralization of gold http://www.biotech-weblog.com/50226711/biomineralization_of_gold_by_bacteria.php
Retrieved 11/12/08
Bioremediation http://jackandshaun.pbwiki.com/ Retrieved 11/13/08
Oil-eating Bacteria http://www.jamstec.go.jp/jamstec/bio2.gif Retrieved 11/13/08
Bacterial shapes http://porpax.bio.miami.edu/~cmallery/150/proceuc/c8.27x3.bact.shapes.jpg retrieved 11/13/08
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