Prokaryotic Groups
1. Domain: Archaea
2. Domain: Bacteria
-
archaea and bacteria ~ “organisms”
1. Domain Bacteria
a. Gram-Negative Bacteria
i. Phylum Proteobacteria
➢ Most gram-negative, largest taxonomic grp
➢ Chemoheterotrophic ~ presumed it has arisen from
common photosynthetic ancestor.
➢ phylogenetic relationship is based upon rRNA studies.
1. Class: Alphaprobacteria
➢ Most of probacteria
➢ Capable of growth within very low level of nutrients.
➢ Unusual morphology: prosthecae stalks or buds
➢ Agriculturally important capable of nitrogen fixation in
symbiosis w/ plants, and human pathogens
i. Pelagibacter (Pelagibacter ubique)
ii. Azospirillum – soil bacterium growing in roots or
tropical grasses
iii. Acetobacteraceae – aerobic organism to convert
ethanol to acetic acid (Acetobacter, Gluconobacter)
1. Ricketssia
2. Ehrlichia
3. Caulobacter and Hyphomicrobium
4. Rhizobium, Bradyrhizobium, and
Agrobacterium
5. Bartonella
6. Brucella
7. Nitrobacter and Nitrosomonas
8. Wolbachia
2. Class: Betaproteobacteria
➢ uses nutrient substances that diffuse away from areas of
anaerobic decomposition of organic matter (ammonia,
methane, H gas)
i. Acidthiobacillus
ii. Spirillum
iii. Sphaerotilus
iv. Burkholderia
v. Bordetalla
vi. Neisseria
vii. Zoogloea
3. Class: Gammoproteobacteria
➢ Largest subgroup
➢ Great variety of physiological types
i. Order: Thiotrichales 1. Begglatoa (Beggiatoa)
2. Francisella
ii. Order: Pseudomonadales
1. Pseudomonas
2. Azotobacter and Azomonas
3. Moraxella
4. Acinetobacter
iii. Order: Legionellales
1. Legionella
2. Coxiella
iv. Order: Vibronales
v. Order: Enterbacteriales – anaerobic, gramnegative rod that are motile, and peritrichously
flagellated; Eneterics – they inhabit the intestinal
tracts of humans an dother animals; most are active
fermenters of glucose and other carbohydrates
1. Escherichia
2. Salmonella
3. Shigella
4. Klebsiella
5. Serratia
6. Proteus
7. Yersinia
8. Erwinia
9. Enterobacter
10. Cronobacter
vi. Order: Pasteurallales - non-motile, human and
animal pathogens
1. Pasteurella
2. Haemophilus
4. Class: Deltaprotobacteria
➢ Distinctive; may include bacteriathat are predators on
other bacteria
➢ Important contribution in sulfur cycle
i. Bdellovibrio
ii. Order: Desulfovibrionales – sulfur reducing; that
oxidizes forms of sulfur such as sulfate
iii. Order: Myxococcales
5. Class: Epsilonproteobacteria
➢ Slender gram-negative rod with helical or curved shape.
➢ 2 genera with both motile (flagella and microaerophilic)
i. Campylobacter
ii. Helicobacter
Nonproteobacteria gram-negative bacteria
2. Cyanobacteria (The Oxygenic Photosynthetic Bacteria)
- Blue green (cyan)/ blue green algae
- Carry out photosynthesis and capable of fixing nitrogen gas from atmosphere (at
hetercysts)
- Uses gliding motility for locomotion.
-
simple diffusion, binary fission, colonial; reproduce by fragmentation of the
filaments.
3. Phyla Chlorobi and Cloroflexi (Anoxygenic Photosynthetic Bacteria)
- Chlorobi – green sulfur bacteria
- Chloroflexi – green nonsulfur bacteria
- Both produce no oxygen during photosynthesis
-
Photosynthetic gram-negative bacteria (purple sulfur bacteria –
gammaproteobacterial) and purple nonsulfur bacteria (alpha and betaproteobacteria
4. Chlamydiae
a. Chlamydia and Chlamydophila
5. Planctomycetes
6. Bacteriodetes
a. Bacteroides
b. Cytophaga
7. Fusobacteria
a. Fusobacterium
8. Spirochaetes
a. Treponema
b. Borella
c. Leptospira
9. Deinococcus-Thermus
Gram-positive bacteria
- Firmicutes (low G + C ratios)
- Actinobacteria (high G + C ratios)
1. Firmicutes (Low G + C Gram Positive Bacteria)
➢ Important endospore-forming bacteria (e.g. genera
Clostridium and Bacillus + Staphylococcus, Enterococcus,
Streptococcus ++ Lactobacillus)
i. Clostridiales
1. Clostridium
2. Epulopiscium
ii. Bacillales – rods and cocci
1. Bacillus – rods and endospore
2. Staphylococcus – grape-like
iii. Lactobacillales – lactic acid producing bacteria
1. Lactobacillus
2. Streptococcus
a. Beta-hemolytic streptococci
b. Non-beta-hemolytic streptococci
3. Enterococcus
4. Listeria
2. Tenericutes (Low G + C content)
➢ Wall-less bacteria “mycoplasmas”
➢ Highly pleomorphic due to lack of cell wall
➢ Produce filaments and resembles fungi
3. Actinobacteria (high G + C Gram-Positive Bacteria)
➢ Mycobacteriunm
➢ Corynebacterium
➢ Propionibacterium
➢ Garneralla
➢ Frankia
➢ Streptomyces
➢ Actinomyces
➢ Nocardia
Domain Archaea
- Lack peptidoglycan.
- Shared many rRNA sequence.
- Found in extreme environmental conditions Extremophiles (halophiles,
thermophiles, and acidophiles) – pathogenic archaea