prokaryotes prokaryotes - outline · prokaryotes chapter 27 prokaryotes - outline ... cyanobacteria...

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Prokaryotes

Chapter 27Prokaryotes - Outline

• Prevalence of Prokaryotes• Structure• Metabolic Diversity• Comparison with Eukaryotes• Eubacteria and Archaebacteria• Classification of Prokaryotes• Examples of Prokaryotes & Diseases• Benefits of Prokaryotes

Prevalence of Prokaryotes• Oldest

– present 2 billion years before eukaryotes• Microscopic & Structurally simplest organisms

– Prokaryotic cell organization• Most abundant

– 5,000 – 500,000 species? – Distribution – everywhere

• Importance– Decomposition– Nitrogen fixation– Photosynthesis– Disease– Gene technology

Prokaryotic Cell Structure

Fig. 27.6

Prokaryotic internal membranes

Aerobic bacterium Cyanobacterium

Bacterial formBacillus Coccus Spirillum

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Bacteria Cell Walls: Gram Stain Bacterial Growth

1. Reproduction Binary Fission

2. Factors reducing growthRefrigerationAbsence of proper nutrientsRelative lack of waterHigh salt concentrationsExtremes in pH

3. Stable states Endospores

1. Mutationspontaneous errors in DNA replicationE. coli 5000 genes 1 mutation/million genes.… 1 mutation in 200 bacteria… 1 billion bacteria in 1 spoonful of soil… 5 million mutant bacteria in 1 spoonful of soil!

2. Genetic recombination

Conjugation & plasmid transfer

Viruses

Prokaryotic Variation Prokaryote Energy Metabolism

Autotrophic Metabolism

Heterotrophic Metabolism

ExamplesCarbon Source

Energy SourceMetabolism

Green sulfur bacteriaPurple sulfur bacteriaCyanobacteria

CO2SunlightPhotoautotroph

Purple non-sulfur bacteriaGreen non-sulfur bacteria

Organic compounds

SunlightPhotoheterotroph

Nitrifying bacteriaDeep sea thermal vents

CO2S, NH3, NH2, H2S, Fe+2

Chemoautotroph

Most common bacteriaOrganic compounds

Organic compounds

Chemoheterotroph

Comparison of Eukaryotes & Prokaryotes

NoYesTrue nucleus

ProkaryotesEukaryotesCharacteristic

0.2 – 2.0 microns> 10.0 micronsCell Size

Naked circular DNA+ HistonesChromosomes

TransformationConjugation

MeiosisGenetic recombination

NoYes and NoMulticellularity

Naked circular DNA+ HistonesChromosomes

Binary fissionMitosisCell division

NoYesInternal Compartments

Single flagellin fiber. Spinning movement.

9+2 microtubulesWhiplike movement.

Flagella

• Historical– Energy metabolism– Motility– Unicells or colonies– Spore formation

• Contemporary classification– Amino acid sequences– Nucleic acid base composition (G/C ratios)– Gene & RNA sequencing– Whole genome sequencing

Criteria to Classify Prokaryotes

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Prokaryote Classification

AncestralProkaryote

Domain KingdomArchaea Archaebacteria

Domain KingdomBacteria Bacteria

Start protein synthesis with

Streptomycin sensitivity

Introns

Gene translation & Ribosomal proteins

Plasma membrane Phospholipids

Cell wall

Characteristic ArchaebacteriaBacteria

Present, not Peptidoglycan

Present & with Peptidoglycan

Branched chainsStraight chains

Eukaryote-like ribosomes

Small ribosomes

YesNo

NoYes

MethionineFormyl methionine

Comparing Bacteria and Archaebacteria

Prokaryote Classification: Archaebacteria

AncestralProkaryote


ExtremophilesMethanogensThermophilesHalophilesAcidophiles

Bacteria

Archaebacteria- halophilesHalobacterium halobium- a photoheterotroph

Light drives proton gradient for ATP synthesis

Solar evaporation pond: white is sodium carbonate, red/pink is Halobacterium.

Many have Sulfur – based metabolism…oxidize elemental sulfur to sulfuric acid…reduce elemental sulfur in respiration.…require high temperature (80-105C)

Archaebacteria - Thermoacidophiles

Sulfolobus acidocaldariusGrowth conditions:

pH 1.0 at 95CHabitat: mud potsOxidizes sulfur to sulfuric acid

Archaebacteria - methanogensGenus: Methanococcus

Habitat: Deep ocean vents: 2600 meters (3600psi)

Energy source: H2

Carbon source: CO2

Temp: 50 – 86C

Strict Anaerobe

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Prokaryote Classification

AncestralProkaryote


Domain KingdomBacteria Bacteria

Prokaryote Classification: Major Groups of Bacteria

Ancestral Bacteria

Aquificae

Gram +

# of species

ThermotogaeDeinococcus

27………..few………..few………..

2475.…….…SpirochaetesCyanobacteria

Chlamydiae

92………..78………..

few………..

Proteobacteria (gram -) 1644………....

Group

Prokaryote Classification: Bacteria

Ancestral Bacteria

Aquificae

Gram +

# of species


27………..few………..few………..


Chlamydiae

92………..78………..

few………..


Group

Thermus aquaticusThermophileChemoheterotrophTaq polymerase used in PCR

Prokaryote ClassificationAncient Bacteria

AquificaeAquifexHyperthermophile 85CChemoautotrophoxidizes H2 or S

DeinococcusDeincoccus radioduransChemoheterotrophTolerates radiationup to 30,000 Gray units(5Gy kills a human)


Ancestral Bacteria

Aquificae

Gram +

# of species


27………..few………..few………..


Chlamydiae

92………..78………..

few………..


GroupProkaryote Classification: Bacteria

Gram +

Low G/C

High G/C

Solitary cellsBacillusClostridiumStaphylococcusStreptococcus

Branching filamentsStreptomycesActinomycesMycobacterium tuberculosisMycobacterium leprae

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Prokaryote Classification: BacteriaGram +

Low G/C

High G/C



Kingdom: BacteriaBacteria: Gram Positive & Low G/C

Bacillus (gram stained)

Bacillus thuringensisBt protein

bacterial pesticide

Bacillus anthraxisBiological

warfare agent

ClostridiumSpecies(tetani,

botulinum)

Botox movie see http://www.botox.com/site/professionals/product_info/mechanism_of_action.asp

Kingdom: BacteriaGram Positive & Low G/C

Streptococcal diseasesDental cariesPneumonia Sore throatImpetigoNecrotizing fasciitisStreptococcal toxic shock syndrome (STSS)

Impetigo

Prokaryote Classification: BacteriaGram +

Low G/C

High G/C



Kingdom: BacteriaBacteria: Gram Positive & High G/C

Branching bacteria = Actinomyces & Streptomyces

Actinomyces from oral cavities

Actinomyces/Streptomyces from soilAntibiotics … streptomycin

tetracycline

Streptomyces verticillusproduces bleomycinantitumor antibiotic glycopeptideTreatment of carcinomas & lymphomas


Ancestral Bacteria

Aquificae

Gram +

# of species


27………..few………..few………..


Chlamydiae

92………..78………..

few………..


Group

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Kingdom: Bacteria: Gram Negative Spirochaetes Borrelia burgdorferi

(Lyme disease)

Bullseye rash of lyme disease

Bullseye rash, thenHeadache, stiff neck, fatigue. More serious cases: Encephalitis ArthritisMyocarditis


Ancestral Bacteria

Aquificae

Gram +

# of species


27………..few………..few………..


Chlamydiae

92………..78………..

few………..


Group

Filamentous: Anabaena

Filamentous: Spirulina

Colonial: Gloeocapsa

Filamentous: Oscillatoria

Kingdom: Bacteria Cyanobacteria - Photosynthetic bacteria

Heterocyst

Kingdom: Bacteria : Gram Negative CyanobacteriaPhotosynthetic bacteria

Genus: Microcystis produces Microcystins liver toxins

Blooms of cyanobacteria


Ancestral Bacteria

Aquificae

Gram +

# of species


27………..few………..few………..


Chlamydiae

92………..78………..

few………..


Group

Kingdom: Bacteria: Gram Negative Chlamydias STD Urogenital, respiratory or eye infections

Intracellular energy parasites

Chlamydia in epithelial cells

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Ancestral Bacteria

Aquificae

Gram +

# of species


27………..few………..few………..


Chlamydiae

92………..78………..

few………..


Group Gram Negative Bacteria

SpirochaetesCyanobacteria

Chlamydiae

92………..78………..

few………..

ProteobacteriaBeta Nitrosomonas fixes Nitrogen

Gamma Enterics Escherichia coliSalmonellaVibrio cholerae

Alpha Rickettsia… Typhus

Epsilon Helicobacter… Peptic ulcers

DeltaBdellovibrio myxobacteriaglide on mucopolysaccharides

Plant remnants

Excess Food

Kingdom: Bacteria: Gram Negative Beta Group ChemoautotrophsNitrosomonas & Nitrobacter Gram Negative Bacteria


Chlamydiae

92………..78………..

few………..






Kingdom: Bacteria: Gram NegativeGamma Group Enterobacteria Escherichia coli

Hamburger disease caused by Escherichia coli O157:H7Symptoms: Hemorrhagic colitis to kidney failure

Sources:undercooked ground beef raw milkunpasteurized apple juice contaminated water red leaf lettuce alfalfa sproutsvenison jerky

E.coli strain, O157:H7Hemolytic Uremic SyndromeEating undercooked ground beef Drinking contaminated water Drinking unpasteurized (raw) milk Working with cattle

Kingdom: Bacteria: Gram NegativeGamma Group Enterobacteria Salmonella

Gastroenteritis fromRaw milkUndercooked poultry

Salmonella typhimuriumDefinitive Type 104 (DT104) –

observed in 1984an antibiotic resistant strain2000 “serotypes” exist

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Gram Negative Bacteria


Chlamydiae

92………..78………..

few………..






hemolymph cells infected with R. rickettsii

Rocky Mountain Lab

Kingdom: Bacteria: Gram NegativeAlpha Group Rickettsias: R. typhi typhus

Rickettsia rickettsii Rocky Mountain spotted fever

Spotted fever rash

Gram Negative Bacteria


Chlamydiae

92………..78………..

few………..






Kingdom: Bacteria: Gram NegativeEpsilon Group Helicobacter pilori Peptic Ulcers

Kingdom: Bacteria: Gram NegativeDelta Group myxobacteria gliding bacteria Importance of Bacteria

• Disease

• Ecology– Decomposers– Producers

• Economic Importance– Genetic engineering– Industrial chemicals: acetic acid, lactic acid– Drugs: streptomycin, erythromycin– Environmental cleanup: oil-degrading bacteria

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prokaryotes prokaryotes - outline · prokaryotes chapter 27 prokaryotes - outline ... cyanobacteria...

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