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11. The Prokaryotes: Domains Bacteria and Archaea. The Prokaryotes. Domain Bacteria. Proteobacteria From the mythical Greek god, Proteus , who could assume many shapes Gram-negative Largest taxonomic group of bacteria. The Alphaproteobacteria. Have prosthecae
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11 The Prokaryotes:Domains Bacteria and Archaea
Domain Bacteria • Proteobacteria • From the mythical Greek god, Proteus, who could assume many shapes • Gram-negative • Largest taxonomic group of bacteria
The Alphaproteobacteria • Have prosthecae • Caulobacter: Stalked bacteria found in lakes • Hyphomicrobium: Budding bacteria found in lakes Figures 11.2b, 11.3
The Alphaproteobacteria • Plant pathogen • Agrobacterium: Insert a plasmid into plant cells, inducing a tumor Figure 9.19
The Alphaproteobacteria • Nitrogen-fixing bacteria • Azospirillum • Grow in soil, using nutrients excreted by plants • Fix nitrogen • Rhizobium • Fix nitrogen in the roots of plants Figure 27.5, step 5
The Betaproteobacteria • Neisseria • Chemoheterotrophic, cocci • N. meningitidis • N. gonorrhoeae • Spirillum • Chemoheterotrophic, helical N. gonorrhoeae Figures 11.4, 11.6
The Betaproteobacteria • Bordetella • Chemoheterotrophic, rods • B. pertussis - causes whooping caugh • Burkholderia: Nosocomial infections • Zoogloea: Slimy masses in aerobic sewage-treatment processes
The Gammaproteobacteria • Pseudomonas • Opportunistic pathogens • Metabolically diverse • Polar flagella • Moraxella: Conjunctivitis Figure 11.7
The Gammaproteobacteria • Legionellales • Legionella • Found in streams, warm-water pipes, cooling towers • L. pneumophilia Figure 24.15b
The Gammaproteobacteria • Vibrionales • Found in coastal water • Vibrio cholerae causes cholera • V. parahaemolyticus causes gastroenteritis • Usually from undercooked shellfish Figure 11.8
The Gammaproteobacteria • Enterobacteriales (enterics) • Peritrichous flagella, facultatively anaerobic • Enterobacter • Erwinia • Escherichia • Klebsiella • Proteus • Salmonella • Serratia • Shigella • Yersinia
The Gammaproteobacteria Proteus mirabilis Figure 11.9
The Gammaproteobacteria • Pasteurellales • Pasteurella multocida • Cause pneumonia and septicemia • Ex. Komodo dragon bite
The Deltaproteobacteria • Bdellovibrio: Prey on other bacteria Figure 11.10
The Deltaproteobacteria • Myxococcales • Gliding • Cells appregate to form myxospores. Figure 11.11b
The Epsilonproteobacteria • Helicobacter • Multiple flagella • Peptic ulcers • Stomach cancer Figure 11.12
Cyanobacteria • Oxygenic photosynthesis • Gliding motility • Fix nitrogen
Purple and Green Photosynthetic Bacteria • Anoxygenic photosynthesis • Purple and green sulfur bacteria light 2H2O + CO2 (CH2O) + H2O + O2 light 2H2S + CO2 (CH2O) + H2O + 2S0 Figure 11.14
Firmicutes • Low G + C • Gram-positive
Clostridiales • Clostridium • Endospore-producing • Obligate anaerobes • Associated Diseases: • Tetanus C. tetani • Botulism C. botulinum • Gas Gangrene C. perfringens • Epulopiscium Clostridium tetani Figures 11.15, 11.16
Bacillales • Bacillus • Endospore-producing rods • Human Pathogen: • B. anthracis • B. cereus Figure 11.17b
Bacillales • Staphylococcus • Cocci • S. aureus – produced many toxins & yellow pigment • Common cause of food poisoning Figure 11.18
Lactobacillales • Generally aerotolerant anaerobes, lack an electron-transport chain • Lactobacillus • Streptococcus • Enterococcus • Listeria Streptococcus Figure 11.19
Mycoplasmatales • Wall-less, pleomorphic • 0.1 - 0.24 µm • M. pneumoniae Figure 11.20a–b
Actinobacteria • Mycobacterium • M. tuberculosis • M. leprae • Propionibacterium acnes • Streptomyces – produce many antibiotics Figure 11.21b
Chlamydias • Have unique life cycle • Chlamydia trachomatis • STD, urethritis
Chlamydias Figure 11.23a
Chlamydophila Figure 11.23b
Spirochaetes • Borrelia – Lyme disease • Treponema pallidum - syphilis Figure 11.24
Bacteroidetes • Anaerobic • Bacteroides are found in the mouth and large intestine • Up to 1 billion per gram of feces
Domain Archaea • Hyperthermophiles • Pyrodictium • Sulfolobus • Methanogens • Methanobacterium • Extreme halophiles • Halobacterium Figure 11.26
Microbial Diversity • 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 • Are a part of complex food chains requiring the products of other bacteria • Need to be cultured to understand their metabolism and ecological role