1. Chapter 27 Prokaryotes Bacteria on the point of a pin

2. Extreme Thermophiles

3. The Three Domains of Life

4. Streptococcus strepto=chain coccus=spherical

5. Bacilli=rod-shaped

6. Spirilla=helical includes spirochetes

7. Largest known prokaryote

8. Another large prokaryote paramecium Prokaryotes vary in size from 0.2µ--750µ

9. Within the past decade, several uncultured bacteria were consecutively announced as the largest known prokaryotes: Epulopiscium fishelsoni (3), Beggiatoa sp. (48), and T. namibiensis (83). Over the years, big bacteria have been described as "megabacteria" or "gigantobacteria" or given names such as "Titanospirillum" (20,30). The current holder of the biovolume record, a chain- forming, spherical sulfur bacterium, T. namibiensis, was discovered only recently in the sea floor off the coast of Namibia (83). The cells may reach 750 [micro]m diameter, clearly visible to the naked eye. They form chains of cells that, due to their light refracting sulfur globules, shine white on the background of black mud and thus appear as a string of pearls (Thiomargarita = sulfur pearl). Also the rod-shaped heterotrophic bacterium, Epulopiscium fishelsoni, found in fish guts may reach a giant size of 80 [micro]m diameter and 600 [micro]m length (3, 10). The largest reported Archaea are probably the extremely thermophilic Staphylothermus marinus, which in culture may occasionally have cell diameters up to 15 [micro]m (19). The smallest prokaryotes are found among both the Archaea and the Eubacteria. The disk-shaped cells of the archaea, Thermodiscus, have diameters down to 0.2 [micro]m and a disk-thickness of 0.1- 0.2 [micro]m (87). Under the collective designation of nanobacteria or ultramicrobacteria, a range of cell forms with diameters down to 0.2-0.3 [micro]m have been found in both natural samples and cultures (92). Altogether, the biovolumes of prokaryotic cells may cover a range of more than 10 orders of magnitude, from

10. Evolution of Prokaryotic Metabolism 1.The Origin of Glycolysis– First prokaryotes 3.5 billion years ago, probably (1)anaerobic chemoheterotrophs. They absorbed organic compounds and used glycolysis (fermentation) to produce ATP in an atmosphere without oxygen. All forms of fermentation produced acidic compounds. 2. The Origin of Electron Transport Chains and Chemiosmosis– The (2)first proton pumps were probably for pH regulation. (3)Later some bacteria used the oxidation of organic compounds to pump H + ’s to save ATP and developed the first Electron Transport Chains. (4)Some got so good at transporting H + ’s that they could actually develop a gradient and use the influx to drive the production of ATP.

11. 3. The Origin of Photosynthesis– (5)The first light absorbing pigments probably provided protection by absorbing UV light. But all pigments throw off electrons when light shines on them so why wouldn’t evolution find a way to use the energy of those electrons? Bacteriorhodopsin in extreme halophiles (6)uses light energy to pump H + ’s out of the cell and produce a gradient which is then used to produce ATP (cyclic photophosphorylation with Photosystem I). Photoheterotrophs 4. Cyanobacteria, Photoautotrophs, Splitting H 2 O and Producing O 2 – (7)Photosystem II evolved in cyanobacteria and they split water and released free oxygen. The oxygen was toxic to many organisms which became extinct. (First Great Extinction) Photoautotrophs

12. 5. Origin of Cellular Respiration– (8)Some prokaryotes modified their photosynthetic ETC’s to reduce the level of toxic O 2. The purple non-sulfur bacteria still use their ETC’s for both photosynthesis and respiration. Eventually (9)some bacteria used O 2 to pull electrons through proton pumps and aerobic respiration began. aerobic chemoheterotrophs

13. Cell Walls All the proteobacteria and the eubacteria have peptidoglycan cell walls. Archaebacteria have a different type of cell wall. Cell walls protect bacteria from cytolysis in hypotonic solutions but can not protect them from plasmolysis in hypertonic solutions. Mycoplasmas without cell walls are susceptible to both. Penicillin denatures (noncompetitive inhibitor) the enzyme that bacteria use to form their cell walls and leaves them susceptible to cytolysis.

15. Gram-positive diplococcus

16. Gram-positive staphlococcus and Gram-negative diplobacillus

17. Bacillus with Pilli-used for conjugation, attachment to surfaces and snorkels for getting oxygen

18. Bacterial flagella rotate rather than bend

19. Bacteria with flagella

23. Infolding of the plasma membrane give these bacteria respiratory membranes and thylakoid-like membranes

24. Bacteria growing on agar in a petri dish

25. Mold cultures

26. An anthrax endospore

27. Endospores

30. ARCHAEA

31. Extreme halophiles in seawater evaporation ponds that are up to 20% salt; colors are from bacteriorhodopsin a photosynthetic pigment very similar to the pigment in our retinas

32. Hot springs with extreme thermophiles

33. Hydrogen Sulfide Metabolizing Chemoautotrophic Archaea found in sulfur springs

34. Eubacteria

35. The Proteobacteria are a major group (phylum) of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella(rod-shaped Gram-negative enterobacteria that causes typhoid fever and the foodborne illness salmonellosis, Vibrio(motile gram negative curved- rod shaped bacterium with a polar flagellum that causes cholera in humans.), Helicobacter(stomach ulcers), and many other notable genera.[1] Others are free-living, and include many of the bacteria responsible for nitrogen fixation. The group is defined primarily in terms of ribosomal RNA (rRNA) sequences, and is named for the Greek god Proteus (also the name of a bacterial genus within the Proteobacteria), who could change his shape, because of the great diversity of forms found in this group.phylum bacteriapathogens EscherichiaSalmonellaGram-negative enterobacteriatyphoid feverfoodborne illnesssalmonellosisVibriogram negativebacteriumflagellum cholerahumansHelicobacter[1]nitrogen fixationribosomal RNA Proteusbacterial genus

36. All Proteobacteria are Gram-negative, with an outer membrane mainly composed of lipopolysaccharides. Many move about using flagella, but some are non-motile or rely on bacterial gliding. The last include the myxobacteria, a unique group of bacteria that can aggregate to form multicellular fruiting bodies. There is also a wide variety in the types of metabolism. Most members are facultatively or obligately anaerobic and heterotrophic, but there are numerous exceptions. A variety of genera, which are not closely related to each other, convert energy from light through photosynthesis. These are called purple bacteria, referring to their mostly reddish pigmentation.Gram-negativeouter membranelipopolysaccharidesflagellabacterial glidingmyxobacteriametabolismanaerobicheterotrophicphotosynthesispurple bacteria

37. Alpha Proteobacteria Rocky Mountain Spotted Fever Ti plasmid Symbiosis with Legumes

38. Alpha Proteobacteria

39. Fruiting bodies of myxobacteriamyxobacteria

40. Helicobacter pylori causes stomach ulcers

41. The Rickettsia are Gram-negative, obligate intracellular bacteria that infect mammals and arthropods. R. prowazekii is the agent of epidemic typhus. During World War I, approximately 3 million deaths resulted from infection by this bacterium. In World War II, the numbers were similar. This agent is carried by the human louse; therefore, disease is a consequence of overcrowding and poor hygiene. Rocky Mountain spotted fever and Q fever remain relatively common.

42. Rhizobium

43. Streptomycetes-soil bacteria that produces an antibiotic

44. Sulfur bacteria that split H 2 S in photosynthesis

45. Cyanobacteria with heterocysts-specialized cells with the enzymes for nitrogen fixation

46. Another Cyanobacteria

49. Cyanobacteria

51. Algae Blooms

52. Spirochete

53. Bull's-eye rash of a person with Lyme disease Spirochete that causes Lyme disease

54. Bull's-eye rash of a person with Lyme disease

55. Deer tick that carries the spirochetes that cause Lyme disease

56. Spirochete that causes Syphilis

57. Mycoplasms that cause Chlamydiae No cell wall and smallest of eubacteria

58. Mycoplasmas-covering a human fibroblast cell

59. Chlamydias living inside an animal cell

60. Mycoplasms that cause Chlamydiae

61. Mutualism of a bioluminescent bacteria in a “headlight fish”

62. The yellow bacillus is a pathogenic bacteria that causes respiratory infections on the membranes inside the nose.

63. The blue bacteria on this slide are commensal living on the membranes inside the nose but causing no harm.

64. Opportunistic infection Koch’s postulates Gram-positive actinomycetes causes tuberculosis destroys tissues Clostridium botulinum releases exotoxins in food it is an obligate anaerobe Vibrio cholerae releases an exotoxin that causes severe diarrhea Salmonella typhi endotoxins that cause typhoid fever, another species of Salmonella causes common food poisoning due to endotoxins explains why it takes 12 -48 hours for symptoms to show up

65. Bioremediation bacteria breakdown sewage

67. Spraying fertilizer on oil spills for Bioremediation

70. Smaller bacteria attacking a larger one

71. Conjugation “caught in the act”