Bacteria

Origins - Three Domain Classification

PROKARYOTESEU

I. Origins of Bacteria

EubacteriaArchaebacteria

Prokaryotes

A. Prokaryotes = 1. Kingdom Eubacteria

2. Kingdom Archaebacteria3. Prokaryote =

does not have a nucleus

I.I. OriginsOriginsB. B. 3.5 billion years ago3.5 billion years ago

C. FIRST LIFE FORMSC. FIRST LIFE FORMS were: were: Archaebacteria, or ancient bacteria Archaebacteria, or ancient bacteria

(how do we know this?)(how do we know this?)

early Earth atmosphere had almost no Oearly Earth atmosphere had almost no O22

D. EubacteriaD. Eubacteria is true bacteriais true bacteria ((EuEu = true= true))

EuEukaryote = karyote = true nucleustrue nucleus

II. Archaebacteria

A. General Info. 1. EXTREME ! Primitive bacteria2. 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. EubacteriaIII. Eubacteria

A. General A. General 1. Ubiquitous1. Ubiquitous = they exist everywhere, = they exist everywhere,

most of the most of the bactibacti. we know. we know

2. Harmful2. Harmful –– pathogenic (they cause pathogenic (they cause disease)disease)

3. Helpful3. Helpful –– they have a variety of usesthey 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 Bacteria1. Food & Drink Production

Fermentation (drinks)– Wine, beerDairy products– Cheese, sour cream, yogurt, sourdough,

Other-Pickles, vinegar,sauerkraut

Helpful Bacteria

2. Sewage DecompositionBacteria break down the organic matter

Helpful Bacteria

3. Water Treatment

Helpful Bacteria

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Where is most of the Nitrogen found on planet Earth?In the atmosphere

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Where do plants need it to be?In the soil

4. Nitrogen Fixation in roots– Helps plants take up H2 O and

nutrients from soil

Helpful Bacteria5. Bio-mineralization in Mining

– Bacteria concentrate desired elements from ore

– E.g. Au (gold)

Cu (copper)

Ralstonia metallidurans, is capable of precipitating dissolved gold.

Helpful Bacteria6. Bio-

remediation– 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 Snow- Making– Bacteria allow

H2 O to form ice crystals

Bacterial Classification1. Shape and Groupings

2. Cell wall composition

3. Environment

4. DNA Sequences

Bacterial Cell

Bacterial StructureBacterial StructureCell WallCell Wall

Prevents cell from rupturingPrevents cell from rupturingComposition of cell wall helps to identify Composition of cell wall helps to identify bacteriabacteria

Bacterial StructureBacterial Structure

Cell MembraneCell MembraneF(xF(x) = support & protect) = support & protectDifferentially permeableDifferentially permeable

CytoplasmCytoplasmContains organelles (nonContains organelles (non--membranous)membranous)

Bacterial StructureBacterial StructureGenetic MaterialGenetic Material

Single, circular chromosomeSingle, circular chromosomePlasmid Plasmid = extra chromosome that can = extra chromosome that can replicate separately from the main replicate separately from the main chromosomechromosome•• Use as vectorUse as vector for biological engineeringfor biological engineering•• Can pass genes for Can pass genes for antibiotic resistanceantibiotic resistance to to

other bacteria (sometimes resistance to other bacteria (sometimes resistance to

several antibiotics @ one time)several antibiotics @ one time)

Bacterial StructureBacterial StructureRibosomesRibosomes

F(xF(x) is to synthesize proteins) is to synthesize proteins

Bacterial StructureBacterial Structure

Capsule (Slime Layer)Capsule (Slime Layer)viscousviscous coating outside of bacteria cell wallcoating outside of bacteria cell wallF(x)sF(x)s::

•• ProtectionProtection•• bacteriabacteria’’s s pathogenicitypathogenicity (or ability to cause disease)(or ability to cause disease)•• Protects bacteria from the Immune System (WBCProtects bacteria from the Immune System (WBC’’s)s)

Bacterial StructureBacterial StructureOther structures (Appendages)Other structures (Appendages)

FlagellaFlagella (protein appendage)(protein appendage)•• F(xF(x) = locomotion) = locomotion•• Cell can have one, two, or manyCell can have one, two, or many

PiliPili (hair(hair--like extensions)like extensions)•• F(x)sF(x)s = attachment to host and transfer of = attachment to host and transfer of

genetic materialgenetic material

FimbriaeFimbriae (shorter than (shorter than pilipili))•• F(xF(x) = adhesion to surfaces) = adhesion to surfaces

Flagella

Bacterial ShapesBacterial ShapesA. TypicalA. Typical

1.1. Coccus/CocciCoccus/Cocci = = spherical or roundspherical or round

2.2. Bacillus/BacilliBacillus/Bacilli = = rodrod--shapedshaped

3.3. Spirillum/SpirilliSpirillum/Spirilli = spiral= spiral--shapedshaped

Bacterial Shapes

Bacterial GroupingsBacterial Groupings

Groups determined by the plane Groups determined by the plane in which the cell dividesin 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 ShapesB. Atypical1. PleomorphicVariable in shape and sizeEg. Stella (stars)Eg. Arcula (cubes)

2. MycoplasmasLack rigid cell wallsCan 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)Penicillin (a fungus)•• Antibiotic inhibits synthesis of Antibiotic inhibits synthesis of

peptidoglycanpeptidoglycan; ; used on actively growing used on actively growing

organisms.organisms.––Gram (+) cellsGram (+) cells PenicillinPenicillin

works works ––Gram (Gram (--) cells) cells PencillinPencillin

doesndoesn’’t work so wellt 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• 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

• Image of Dead Sea www.pjsoaps.com/1DeadSeaSpa.html Retrieved 11/27/07• 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