Microbial Classification

1
Microbial Classification
2
The Prokaryotes Domains Bacteria and Archaea

• One circular chromosome, not in a membrane
• No histones
• No organelles
• Peptidoglycan cell walls
• Binary fission

3
Domain Bacteria

• Proteobacteria
• Mythical Greek god, Proteus, who could assume
  many shapes
• Gram-negative

4
The ? (alpha) Proteobacteria

• Human pathogens
• Bartonella
• B. hensela Cat-scratch disease
• Brucella Brucellosis

5
The ? (alpha) Proteobacteria

• 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

6
The ? (alpha) Proteobacteria
Figure 11.1
7
The ? (alpha) Proteobacteria

• Wolbachia. Live in insects and other animals

8
The ? (alpha) Proteobacteria

• Have prosthecae
• Caulobacter. Stalked bacteria found in lakes
• Hyphomicrobium. Budding bacteria found in lakes

Figure 11.2 3
9
The ? (alpha) Proteobacteria

• 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
10
The ? (alpha) Proteobacteria

• Produce acetic acid from ethyl alcohol
• Acetobacter
• Gluconobacter

11
The ? (beta) Proteobacteria
12
The ? (beta) Proteobacteria

• Thiobacillus
• Chemoautotrophic, oxidize sulfur H2S ? SO42
• Sphaerotilus
• Chemoheterotophic, form sheaths

Figure 11.5
13
The ? (beta) Proteobacteria

• Neisseria
• Chemoheterotrophic, cocci
• N. meningitidis
• N. gonorrhoeae
• Spirillum
• Chemoheterotrophic, helical

Figure 11.4 6
14
The ? (beta) Proteobacteria

• Bordetella
• Chemoheterotrophic, rods
• B. pertussis
• Burkholderia. Nosocomial infections
• Zoogloea. Slimy masses in aerobic
  sewage-treatment processes

15
The ? (gamma) Proteobacteria
16
The ? (gamma) Proteobacteria

• Pseudomonadales
• Pseudomonas
• Opportunistic pathogens
• Metabolically diverse
• Polar flagella
• Azotobacter and Azomonas.
• Nitrogen fixing
• Moraxella.
• Conjunctivitis

Figure 11.7
17
The ? (gamma) Proteobacteria

• Legionellales
• Legionella
• Found in streams, warm-water pipes, cooling
  towers
• L. pneumophilia
• Coxiella
• Q fever transmitted via aerosols or milk

Figure 24.15b
18
The ? (gamma) Proteobacteria

• Vibrionales
• Found in coastal water
• Vibrio cholerae causes cholera
• V. parahaemolyticus causes gastroenteritis

Figure 11.8
19
The ? (gamma) Proteobacteria

• The ? (gamma) Proteobacteria
• Enterobacteriales (enterics)
• Peritrichous flagella, facultatively anaerobic
• Enterobacter
• Erwinia
• Escherichia
• Klebsiella
• Proteus
• Salmonella
• Serratia
• Shigella
• Yersinia

20
The ? (delta) Proteobacteria
21
The ? (delta) Proteobacteria

• Bdellovibrio. Prey on other bacteria
• Desulfovibrionales. Use S instead of O2 as final
  electron acceptor
• Myxococcales. Gliding. Cells aggregate to form
  myxospores

22
The ? (delta) Proteobacteria
Figure 11.10a
23
The ? (delta) Proteobacteria
Figure 11.1b
24
The ? (epsilon) Proteobacteria
25
The ? (epsilon) Proteobacteria

• Campylobacter
• One polar flagellum
• Gastroenteritis

Figure 11.1a
26
The ? (epsilon) Proteobacteria

• Helicobacter
• Multiple flagella
• Peptic ulcers
• Stomach cancer

Figure 11.1b
27
The Nonproteobacteria Gram-Negative Bacteria
28
Cyanobacteria

• Oxygenic photosynthesis
• Gliding motility
• Fix nitrogen

29
Purple and Green Photosynthetic Bacteria

• Anoxygenic photosynthesis
• Purple and green sulfur bacteria

light
2H2O CO2
(CH2O) H2O O2
light
2H2S CO2
(CH2O) H2O 2S0
30
Chlamydiae

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

31
In Bergey's Manual, Volume 5
Figure 11.22a
32
In Bergey's Manual, Volume 5
Figure 11.22b