Chapter 11 Powerpoint lecture - Bethel College

TORTORA • FUNKE

• CASE

Microbiology AN INTRODUCTION EIGHTH EDITION

B.E Pruitt & Jane J. Stein

Chapter 11 The Prokaryotes: Domains Bacteria and Archaea

The Prokaryotes: Domains Bacteria and Archaea • One circular chromosome, not in a membrane • No histones • No organelles • Peptidoglycan cell walls • Binary fission Learning objective:

PowerPoint® Lecture Slide Presentation prepared by Christine L. Case Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Make a dichotomous key to distinguish among the aproteobacteria described in this chapter.

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Domain Bacteria

Bergey’s Manual • Categorizes bacteria into taxa based upon rRNA sequences • Lists identifying characteristics like: • Gram stain reaction • cellular morphology • oxygen requirements • nutritional properties • Prokaryotes classified into two domains: • Bacteria • Archaea Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

• Bacteria essential to life on earth • Proteobacteria • Mythical Greek god, Proteus, who could assume many shapes • Gramnegative Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

The α (alpha) Proteobacteria

• Human pathogens: • Bartonella


• B. hensela

Cat-scratch disease

• Brucella

Brucellosis


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• Includes nitrogen-fixing bacteria, chemoautotrophs, and chemoheterotrophs • Obligate intracellular parasites: • Ehrlichia. Tick-borne, ehrlichiosis • Rickettsia. Arthropod-borne, spotted fevers • R. prowazekii

Epidemic typhus

• R. typhi

Endemic murine typhus

• R. rickettsii

Rocky Mountain Spotted Fever




Figure 11.1


• Wolbachia. Live in insects and other animals

• Have prosthecae: • Caulobacter. Stalked bacteria found in lakes

• In an infected pair, only female hosts can reproduce • “Popcorn” strain causes host cells to lyse

• Hyphomicrobium. Budding bacteria found in lakes

• Possible biological control of insects




Figure 11.2 & 3


• Plant pathogen: • Agrobacterium. Insert a plasmid into plant cells, inducing a tumor

• Chemoautotrophic: • Oxidize nitrogen for energy • Fix CO2 • Nitrobacter. NH3+ → NO2– • Nitrosomonas. NO2– → NO3–


Figure 9.17


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• Nitrogen-fixing bacteria: • Azospirillum • Grow in soil, using nutrients excreted by plants

• Produce acetic acid from ethyl alcohol: • Acetobacter • Gluconobacter

• Fix nitrogen • Rhizobium • Fix nitrogen in the roots of plants Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Figure 27.5


The β (beta) Proteobacteria

Learning objective: Make a dichotomous key to distinguish among the β-proteobacteria described in this chapter.



The β (beta) Proteobacteria

The β (beta) Proteobacteria • Spirillum volutans:

• Thiobacillus • Chemoautotrophic, oxidize sulfur: H2S → SO4

2–

• Sphaerotilus

• Note polar flagella

• Chemoheterotophic, form sheaths

• Neisseria

Sphaerotilus natans:

• Chemoheterotrophic, cocci

•Sheathed bacteria found in dilute sewage and aquatic environs


• Chemoheterotrophic, helical

• N. meningitidis

Figure 11.5

• N. gonorrhoeae (diplococci) – fimbriae attach to mucous membranes for greater pathogenicity


Figure 11.4 & 6

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The β (beta) Proteobacteria • Bordetella • Chemoheterotrophic, rods • B. pertussis (pertussis or whooping cough) • Burkholderia. Nosocomial infections (hospital infection) • Extraordinary nutritional spectrum, able to degrade > 100 different organic molecules, can grow in disinfectant! • Zoogloea. Slimy masses in aerobic sewage-treatment processes – essential to sewage treatment



The γ (gamma) Proteobacteria

The γ (gamma) Proteobacteria • Pseudomonadales: • Pseudomonas • Gram • Opportunistic pathogens • Metabolically diverse

Learning objective:

• Polar flagella (characteristic, as in picture)

Make a dichotomous key to distinguish among the γ proteobacteria described in this chapter. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

• Azotobacter and Azomonas.

Nitrogen fixing

• Moraxella.

Conjunctivitis



Figure 11.7


• Legionellales: • Legionella

• Vibrionales:

• Found in streams, warm-water pipes, cooling towers of air-conditioning

• Found in coastal water • Vibrio cholerae causes cholera

• L. pneumophilia (Legionnaire's)

• Slight curvature of rods

• Coxiella • Q fever transmitted via aerosols or milk Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

• V. parahaemolyticus causes gastroenteritis (raw/undercooked shellfish)

Coxiella burnetii

Figure 24.15b


Figure 11.8

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The γ (gamma) Proteobacteria • The γ (gamma) Proteobacteria • Enterobacteriales (enterics – intestinal tracts): • Peritrichous flagella, facultatively anaerobic • Enterobacter • Erwinia • Escherichia • Klebsiella • Proteus • Salmonella • Serratia • Shigella • Yersinia Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

The γ (gamma) Proteobacteria Proteus mirabilis – swarmer due to multiple flagella



Figure 11.9a, b


• Pasteurellales: • Non-motile

• Beggiatoa

• Human and animal pathogens

• Chemoautotrophic, oxidize H2S to S0 for energy

• Pasteurella

• Interface between aerobic and anaerobic layers in aquatic sediments

• Cause pneumonia and septicemia • Haemophilus

• Factor in discovery of of autotrophic metabolism (NAD+,

• Require X factor (heme) and V factor NADP+) factors from blood hemoglobin

• H. influenzae – several important diseases (meningitis, earaches, epiglotitis, bronchitis, etc.) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

• Francisella • Chemoheterotrophic, tularemia


The δ (delta) Proteobacteria

Learning objective: Make a dichotomous key to distinguish among the δ proteobacteria described in this chapter. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings


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• Bdellovibrio. Prey on other bacteria • Desulfovibrionales. Use S instead of O2 as final electron acceptor (sulfur reducing) • Releases tons of H2S into atmosphere, key part in sulfur cycle • Myxococcales. Gliding. Cells aggregate to form myxospores (stalked fruiting body – 2nd slide next) • Leave behind a slime trail (next slide) • Nutrition from bacteria they encounter




Figure 11.10a

The ε (epsilon) Proteobacteria

Learning objective: Make a dichotomous key to distinguish among the ε proteobacteria described in this chapter. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Figure 11.1b


The ε (epsilon) Proteobacteria Helicobacter pylori:

• Helicobacter

Example of a helical bacterium that doesn’t make a complete twist (different from spirochetes)

• Multiple flagella • Peptic ulcers • Stomach cancer • Campylobacter • One polar flagellum • Gastroenteritis


Figure 11.1a


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The Nonproteobacteria Gram-Negative Bacteria

Cyanobacteria • Oxygenic photosynthesis • Once called blue-green algae • Water species have gas vacuoles for buoyancy • Gliding motility • Fix nitrogen in heterocysts • Played important part in development of life on earth, producing oxygen atmosphere

Learning objective: Make a dichotomous key to distinguish among the gramnegative nonproteobacteria described in this chapter. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings


Cyanobacteria


Figure 11.12a-c


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Purple and Green Photosynthetic Bacteria Learning objective: Compare and contrast purple and green photosynthetic bacteria with cyanobacteria

• Anoxygenic photosynthesis • Purple and green sulfur bacteria (bottom formula) 2H2O + CO2

2H2S + CO2

light

light

(CH2O) + H2O + O2

(CH2O) + H2O + 2S0

Purple sulfur bacteria: intracellular sulfur granules (multicolored refractile objects (anoxygenic photoautotrophs) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings


Firmicutes

Clostridiales

• Low G + C

Learning objective:

• Gram-positive

Make a dichotomous key to distinguish among the low G + C gram-positive described in this chapter.

• Clostridium • Endosporeproducing • Obligate anaerobes • Endospores usually distend the cell wall • Epulopiscium • Very large, shown on the head of a pin • rRNA determined placement with prokaryotes



Bacillales

Figure 11.14 & 15

Bacillales • Staphylococcus aureus • Cocci in grapelike clusters • Gram-positive, produces enterotoxin • Grow fairly well under high osmotic pressure and low moisture (nasal secretions, skin, ham and other cured meats)

• Bacillus • Endospore-producing rods • B. anthracis - anthrax


Figure 11.16b


Figure 1.17

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Lactobacillales • Generally aerotolerant anaerobes, lack an electron-transport chain

Mycoplasmatales

Streptococcus – many of spherical cells are dividing and somewhat oval

• Lactobacillus – lacticacid producing • Streptococcus – more illnesses and diseases than any other bacteria group • Enterococcus – intestinal tract, oral cavity

• Filamentous growth of M. pneumoniae • Reproduces by fragmentation of the filaments

• Listeria – contaminates dairy Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

• Mycoplasma pneumoniae • No cell walls • Pleomorphic (irregular cells) • Arrows indicate terminal structures that likely aid attachment to eukaryotic cells • 0.1 - 0.24 µm

Figure 11.18


Actinobacteria • High G + C • Gram-positive

Figure 11.19a, b

Actinobacteria

Learning objective: Make a dichotomous key to distinguish among the high G + C gram-positive described in this chapter.

• Actinomyces • Corynebacterium • Frankia • Gardnerella • Mycobacterium • Nocardia • Propionibacterium • Streptomyces



Figure 11.20b

• Streptomyces – • Filamentous branching growth with asexual reproductive conidiospores at tips • Make up much of soil bacteria


Actinomyces – notice branched filamentous morphology


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Chlamydiae

Generalized life cycle of Chlamydia (48 hours)

• C. trachomatis • Trachoma • STD, urethritis • C. pneumoniae • C. psittaci • Causes psittacosis



Generalized life cycle of Chlamydia

Figure 11.22a

Spirochaetes • Borrelia

Spirochetes –

• Leptospira

•Helical, axial filaments under outer sheath

• Treponema

•Move by corkscrewlike rotation

Elementary bodies – infectious stage Reticulate bodies – reproduce in host cell Intermediate bodies – stage in between


Figure 11.22b


Phyla Bacteroidetes & Fusobacteria

Domain Archaea

• Anaerobic • Bacteroides. In mouth and large intestine • Cytophaga. Cellulose-degrading in soil

• Hyperthermophiles (heat) • Pyrodictium

• Fusobacterium • Found in mouth • May be involved in dental diseases

Figure 11.23

• Sulfolobus

Archaea – Pyrodictium abyssi: •Deep ocean, 110 degrees C •Cells disk-shaped with network of tubules (cannulae)

• Methanogens (methane) • Methanobacterium • Extreme halophiles (salt) • Halobacterium



Figure 11.25

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Microbial Diversity

Microbial Diversity

Thiomargarita namibiensis:

• Few of the total number of prokaryotes have been isolated and identified

•Energy from reduced sulfur compounds

• PCR indicates up to 10,000 bacteria/gm of soil. Many bacteria have not been identified or characterized because they: • Haven't been cultured • Need special nutrients

• Bacteria size range

• Are part of complex food chains requiring the products of other bacteria

• Thiomargarita (750 µm) to nanobacteria (0.02 µm) in rocks Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

• Need to be cultured to understand their metabolism and ecological role Figure 11.26


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