© 2004 Wadsworth – Thomson Learning Chapter 11 The Prokaryotes

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

© 2004 Wadsworth – Thomson Learning Figure 11.1

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

© 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

© 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

© 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 species Alphaproteobacteria class Betaproteobacteria class Gammaproteobacteria class Deltaproteobacteria class Epsilonproteobacteria class

© 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

© 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

© 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

© 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

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

© 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

© 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

© 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

© 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

© 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

© 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