1. © 2004 Wadsworth – Thomson Learning Chapter 11 The Prokaryotes

2. © 2004 Wadsworth – Thomson Learning Prokaryotic Taxonomy Prokaryotic genealogical tree –Based on 16S ribosomal RNA –Two domains Archaea –Two phyla Bacteria –23 phyla

3. © 2004 Wadsworth – Thomson Learning Figure 11.1

4. © 2004 Wadsworth – Thomson Learning Domain Archaea A1 Crenarchaeota –One class –Morphologically diverse –Metabolically diverse A2 Euryarchaeota –Five classes –Methanogens –Extreme halophiles –Thermoacidophiles

5. © 2004 Wadsworth – Thomson Learning Domain Bacteria B4 Deinococcus-Thermus –Deinococcus radiodurans Resistance to radiation –Thermus aquaticus Production of Taq polymerase B5 Chrysiogenetes –Single species –Anaerobic respiration using arsenate

6. © 2004 Wadsworth – Thomson Learning Domain Bacteria B10 Cyanobacteria –Oxygenic photosynthetic bacteria –Once called blue-green algae (not algae) –Major nitrogen fixer Carbon from CO 2 Nitrogen as N 2 Heterocysts –Specialized cells for fixation of nitrogen –Photosynthesis in other cells

7. © 2004 Wadsworth – Thomson Learning Domain Bacteria B11 Chlorobi –Anoxygenic phototrophic bacteria Anaerobic environments Photosynthetic –Found in deep, clear bodies of water B12 Proteobacteria –Largest phylum 1300+ species Alphaproteobacteria class Betaproteobacteria class Gammaproteobacteria class Deltaproteobacteria class Epsilonproteobacteria class

8. © 2004 Wadsworth – Thomson Learning Alphaproteobacteria Environmentally important genera –Acetobacter Production of acetic acid in vinegar –Agrobacterium Produce cancerlike disease of plants Ti plasmids –Rhizobium and Bradyrhizobium Symbiotic nitrogen-fixing bacteria Root nodules of legumes –Appendaged bacteria Prosthecate bacteria—found in aquatic environs

9. © 2004 Wadsworth – Thomson Learning Betaproteobacteria Bordetella –B. pertussis—causes whooping cough Neisseria –N. meningitidis—meningitis –N. gonorrhoeaea—gonorrhea Sheathed bacteria –Tube surrounding bacteria –Contaminated water and sewage treatment

10. © 2004 Wadsworth – Thomson Learning Gammaproteobacteria 13 orders –Enterobactgeriales Contain the enteric bacteria Include human pathogens –Salmonella typhi –Shigella spp. –Yersinia pestis –Escherichia coli –Vibrionales Curved rods –Vibrio chlerae--cholera –Pasteurellales Pasteurella and Haemophilus genera –Pseudomonales P. aeruginosa

11. © 2004 Wadsworth – Thomson Learning Deltaproteobacteria Sulfur-reducing bacteria –Sulfates and sulfur to hydrogen sulfide –Mud flats, brackish water –Desulfovibrio spp. Black metal sulfides of Black Sea Gliding Fruiting bacteria –Myxobacteria –Soil organisms

12. © 2004 Wadsworth – Thomson Learning Epsilonproteobacteria Campylobacter –C. jejuni—diarrheal illness Helicobacter –H. pylori—gastric ulcers

13. © 2004 Wadsworth – Thomson Learning Domain Bacteria B13 Firmicutes –Three classes Clostridia –Endospore forming –Strict anaerobes Bacilli –Endospore forming –Aerobic and/or facultative anaerobes Mollicutes –Lack cell wall –Mycoplasmas –Gram-positive cocci Spread between Clostridia and Bacilli classes

14. © 2004 Wadsworth – Thomson Learning Domain Bacteria B13 Firmicutes (continued) –Gram-positive cocci Arrangement important for identification Physiological differences –Staphylococcus »Facultative anaerobes Four genera produce lactic acid –Streptococcus spp. –Leuconostoc –Pediococcus –Lactobacillus

15. © 2004 Wadsworth – Thomson Learning Domain Bacteria Actinobacteria –Oddly shaped bacteria Arthrobacter genus –Change shape during growth Bifidobacterium genus –Irregular branched cells »Propionibacterium acne »Corynebacterium diptheriae –Acid-fast Mycobacterium –Tuberculosis and Hansen’s disease Nocardia –Spore-forming Actinomycetes Abundant in soil Figure 11.19

16. © 2004 Wadsworth – Thomson Learning Domain Bacteria B16 Chlamydiae –Obligate intracellular parasites –Complicated reproductive cycle Reticulate body –vegetative cell –multiplication Elementary body –Chlamydiospore –Spread of infection Figure 11.21

17. © 2004 Wadsworth – Thomson Learning Domain Bacteria B17 Spirochaetes –Helical shape –Corkscrew motility Flagella—two axial filaments –Metabolically diverse –Causes of human disease Treponema pallidum—syphilus Leptospira interrogans—leptospirosis Borrelia burgdorferi—Lyme’s disease Figure 11.22

18. © 2004 Wadsworth – Thomson Learning Domain Bacteria B20 Bacteroidetes –Purple nonsulfur bacteria Photosynthetic –Bacteroides Mouth and intestinal tract B21 Fusobacteria –Oral and respiratory systems F. periodonticum –dental abscesses F. nucleatum –Respiratory system