Prokaryote Diversity and

Biology

I. Classification

A. The Original 5 Kingdom system

1. Monera (Prokaryotic, unicellular)

2. Protista (Eukaryotic, unicellular)

3. Fungi (Eukaryotic, uni or multi C)

4. Plantae (Eukaryotic, multicellular)

5. Animalia (Eukaryotic, multicellular)

I. ClassificationB. The Modern 3-Domain System

1. Archaea - Primitive extremes

Prokaryotic

2. Prokarya - Bacteria

3. Eukarya

Kingdom Protista

Kingdom Fungi

Kingdom Plantae

Kingdom Animalia

I. ClassificationC. Comparing Archaea and Bacteria

Archaea Bacteria

Nucleus? Absent Absent

Membrane lipids Branched UnBranched

Peptidoglycan Absent Present

RNA Polymerase Several kinds 1 kind

Introns Present Absent

Antibiotic Not sensitive Sensitive

II. Prokaryote Origins

A. First fossils - 3.5 billion years ago

No other life until 1.5 bya

II. Prokaryote Origins

B. Original forms appear to have been

Anaeorbic

III. Prokaryote Structure

A. Lack membrane bound nucleus

Lack membrane bound organelles

III. Prokaryote Structure

B. Basic shapes

1. Cocci - Spherical

III. Prokaryote StructureB. Basic shapes

2. Bacilli - rod shaped

III. Prokaryote Structure

B. Basic shapes

3. Spirilla - spiral shaped

III. Prokaryote Structure

B. Basic shapes

4. Other terms

Staphylo - clusters

Strepto - chains

Spirochetes - long spirals

III. Prokaryote StructureC. Prokaryote flagellum - movement

Protein structure

Attached by rotary rings ; uses a propeller movement.

III. Prokaryote Structure

D. Short thin extensions - pili (pilus)

Sticks bacteria to eachother and other surfaces

Sex pili - exchange genes during sexual reproduction

III. Prokaryote Structure

E. Endospores - long term dormancy

III. Prokaryote Structure

F. Actinomycetes - branching chain colonies

IV. Prokaryote Nourishment

A. Autotrophs - make own food

Photoautotrophs - photosynthesis

Chemoautotrophs - chemosynthesis

Hydrogen sulfide

IV. Prokaryote Nourishment

B. Heterotrophs

Photoheterotrophs - both

Chemoheterotrophs - both

Saprophytes - feed off the dead

Parasites - feed off a living host

V. The Domain ArchaeaA. Recent Discovery!

V. The Domain Archaea

B. Radical Proteins - somewhat mysterious

V. The Domain Archaea

C. Cells walls - different chemical components

No peptidoglycan

V. The Domain Archaea

D. Membranes have unique structure

V. The Domain Archaea

E. tRNA has unique structure

V. The Domain ArchaeaF. Types

1. Euryarcaeota

Methanogens - anaerobic

Waste material - methane

Habitat - swamp bottoms

and animal guts

V. The Domain ArchaeaF. Types

Euryarcaeota

Halophiles - extreme salty habitats

V. The Domain ArchaeaF. Types

2. Crenarcaeota

Extreme thermophiles

V. The Domain Archaea

F. Types

3. Korarchaeota

Very little known - recent discovery

VI. The Domain Prokarya (bacteria)

A. Bacterial types and classification

1. Proteobacteria

Gram-negative

Large diverse group

A. Bacterial types and classification

2. Clamydias

Gram-negative

Parasites in animals

Lack peptidoglycan

A. Bacterial types and classification

3. Spirochetes

Spiral shape

Includes syphilis and Lyme

A. Bacterial types and classification

4. Gram-Positive Bacteria

Large diverse group

Includes anthrax, botulism

staphyococcus and strepto...

A. Bacterial types and classification5. Actinobacteria

Very large – 30 familiesBacilliOften filamentousMost harmless – found in soil & plantsException – Mycobacteria (TB)Many useful –

Antibiotic productionDairy products

A. Bacterial types and classification

6. Cyanobacteria

Blue-green bacteria

Photoautotrophic

Aquatic

B. Bacteria and Disease

1. Organisms causing disease - pathogen

2. Germ Theory of Disease

Diseases are caused by micro-organisms.

Louis Pasteur

3. Bacterial pathogens release poisons

These cause disease symptoms

Exotoxins - Proteins secreted out

most dangerous

Botulism, staph infections

B. Bacteria and Disease

Endotoxins - components of bacterial cell wall

B. Bacteria and Disease

4. Medical treatment - antibiotics

B. Bacteria and Disease

5. Koch’s Postulates - 1876

Criteria to prove the causative agent of a disease

B. Bacteria and Disease

4. Koch’s Postulates - 1876

a. Same pathogen must be found in each victim host

b. Pathogen must be isolated from a host and grown in culture

c. Cultured pathogen must produce the same disease in an experimental host

d. Same pathogen must be isolated from the experimental host after the disease develops.

V. Microbiology techniques

A. Aseptic Technique - A standardized procedure for handling, transfering, and culturing micro-organisms

V. Microbiology techniquesB. Culturing Bacteria

1. Sterilization

2. Isolation - To isolate a single cell for culturing

Provide culture environment

Streak plate method

Streak with inoculating loop

4 sections

Flame loop between

3. Culture media

Bacteria grown on agar gel

Agar saturated with nutrient media

Defined media

pure chemicals, exact compostion

Complex media - natural sources

called broth

examples - blood, beef, yeast

casein (milk protein)

Nutrient broth - prepared mixture

Luria broth (lb)

C. Bacterial staining methods

Gram stain - 1884

1. Primary stain - Gentian violet

Makes all bacteria purple

2. Mordant - sets the stain - iodine

3. Decolorization - ethanol

gram negative bacteria - lose color

gram positive - retain color

4. Counterstain - Safranin (red)

gram negative - pink

gram positive - deep purple