The Microbial World

1. The Microbial World Kathy Huschle Northland Community and Technical College

2. Historical Perspective • Robert Hooke: 1635 – 1703 • discovered “little boxes” on a thin slice of cork • came to be known as cells, the world’s smallest structural unit • beginning of the cell theory: “all living things are composed of cells” Robert Hooke drawing of fungi

3. VanLeeuwenhoek • van Leeuwenhoek: 1632-1723 • first man to view live microorganisms using a single lens microscope Hooke’s Microscope

4. Animalcules • Van Leeuwenhoek”s “animalcules” • this is what he called them, based on how they moved • drawings are representations of bacteria and protozoa Van Leeuwenhoek drawings of animalcules: found in rainwater soaked in peppercorns and material scraped from teeth

5. Louis Pasteur • spontaneous generation • ability of microorganisms to arise spontaneously from non-living matter • belief until 2nd half of 19th century • proven inaccurate by Louis Pasteur in 1861 Louis Pasteur

6. Louis Pasteur on spontaneous generation • demonstrated the presence of microorganisms in air and their ability to contaminate sterile solutions

7. Spontaneous Generation • proved that “spontaneous” is a result of the presence of microorganisms in the air or the fluids themselves

8. Aseptic Technique • basis of aseptic technique • techniques used to prevent contamination by unwanted microorganisms • standard laboratory practice

9. Golden Age of Microbiology1857 - 1914 • rapid advances in the science of microbiology • fermentation and pasteurization • germ theory of disease Fermentation Process In Lab

10. Fermentation & Pasteurization • fermentation • discovery that yeast (microorganisms) ferments sugar to alcohol in the absence of air • souring and spoiling caused by bacteria in the presence of air sugar to beer: good beer to vinegar: bad Beer Fermentation Tank

11. Fermentation & Pasteurization • pasteurization • use of heat to kill bacteria to diminish spoilage • fermentation and pasteurization solidified the connection between microorganisms and disease Milk Pasteurization Equipment

12. Germ Theory of Disease • proof that bacteria caused disease • Robert Koch 1843-1910 developed the germ theory of disease while studying the cattle disease anthrax • established that Bacillus anthracis was the causative agent “germ” of anthrax in 1876 Robert Koch

13. Vaccination • Edward Jenner developed the first vaccine in 1798 for smallpox • in 1880 Pasteur discovered the use of a virulent bacteria for a vaccine against fowl cholera and coined the term vaccine Edward Jenner

14. Birth of Modern Chemotherapy • chemotherapy: chemical treatment of a disease, including antibiotics and chemicals used to treat cancer • Paul Ehrlich • used arsenic to treat syphilis • Alexander Fleming • penicillin was accidentally discovered

15. Chemotherapeutic Agents • synthetic drugs • chemically prepared in the lab • antibiotics • substances produced naturally by bacteria and fungus • both synthetic drugs and antibiotics inhibit the growth or kill other microorganisms

16. Paul Erlich • first use of a chemotherapeutic agent in 1910 • used an arsenic containing compound to treat syphilis • repeated his experiments with minor changes 605 times before he found a concentration that worked Paul Erlich

17. Alexander Fleming • accidentally discovered that mold (Penicillium) inhibited the growth of bacterial cultures in his lab in 1928 Alexander Fleming

18. Penicillin • usefulness of penicillin was not apparent until the 1940’s • clinically tested and as a result of the test, it was mass produced • World War II spurred on the production of penicillin as it was initially used for the war effort Click on the icon below, then click on “Play the Discovery of the Penicillin Game”. Follow the instructions to help discover Penicillin.

19. Modern Microbiology • new and different directions that the study of microbiology is going towards • drug resistance • new branches of microbiology • develop new vaccines • recombinant DNA technology

20. Drug Resistance • result of genetic changes in microbes • production of microbial enzymes that inactivate antibiotics

21. Drug Resistance • surface changes in microbes • disallowing antibiotics from attaching to it • preventing antibiotics from entering the microbe

22. New Branches of Microbiology • study of microbiology broadened and became more specialized • bacteriology • study of bacteria • mycology • study of fungi Clavaria: a fungi

23. New Branches of Microbiology • parasitology • study of protozoa and parasitic worms • immunology • study of immunity • virology • study of viruses

24. New Vaccines • as new diseases emerge, microbiologists strive to find cures • new vaccines appear to be the best hope as microorganisms continue to develop drug resistance

25. Recombinant DNA Technology • also referred to as genetic engineering • microorganisms are used for the study of genetic engineering for several reasons • short life cycle • less complex structure than plant or animal, but still have DNA

26. Recombinant DNA Technology • used to manufacture large amounts of medical substances • enhances agricultural production • potential for medical breakthroughs in area of genetic diseases

27. Microbes and Human Welfare • microorganisms • beneficial to all life on Earth • microorganisms • degrade dead plants and animals, recycling the nutrients to be used by living plants and animals Soil microbiota decomposing crop residue

28. Microorganisms as Decomposers • microorganisms • decompose organic matter in sewage, breaking it down and releasing the beneficial elements, such as carbon, nitrogen, oxygen and sulfur, back into the environment Sewage Treatment Plant

29. Microorganisms and Bioremediation • microorganisms • are used in bioremediation, a process that cleans up toxic wastes and pollutants

30. Microorganisms and Food Production • microorganisms • used in the production of food

31. Pharmaceuticals • microorganisms • used in the development and production of pharmaceuticals

32. Microorganisms for Medical Uses • microorganisms • used in the process of diagnosis and treatment of human disease Picking cloned yeast colonies for production

33. Microorganisms as the Medical Enemy • the other side of the picture • influenza: 1918-1919 • killed more people than WW1, WW2, Korea, and Viet Nam combined Micrograph of Influenza virus

34. Microorganisms as the Medical Enemy • plaque: 13th century • killed 25% of the population of Europe Plague bacteria

35. Medical Microbiology • resurgence of new diseases is due to any or all of the following • resistance to antibiotics • increase in foreign travel • increase in foreign visitors • parents becoming lax on childhood vaccinations • increase in the # of elderly in the world • the immune system weakens with age

36. Medical Microbiology • emerging diseases due to • changing lifestyles • mutation ability of infectious agents

37. Medical Microbiology Successes • smallpox • last known disease in the world was documented in 1977 • believed at one time prior to eradication, that 80% of the world’s population would be affected by smallpox Smallpox virus Clinical Manifestation of Smallpox

38. Microbiology Successes • potato famine in Ireland • 1850’s • late blight fungus • through the process of genetic engineering, microbiologists are able to protect the potato industry from this plight happening again Blight fungi Infected potato plant

39. What is a Microorganism? • often referred to as a “germ” • very few microbes cause disease • very small life forms • 300 µm 60 µm 3 µm E. coli on the head of a pin

40. Perspective on size • smallest object visible to the naked eye is 0.1 mm which is = to 100 um(micrometers) • most microorganisms range in size from 5um - .1um • viruses, the smallest microorganism, have a size range from .1um – 0.01 um. Click on the icon to for more information on microbial size. Then click on the items listed on the right to gain perspective on how small microorganisms are.

41. Microbial Size

42. 3 Domains of all living organisms • Bacteria • Archaea • Eucarya

43. Bacteria • single-celled prokaryote • prokaryote is a simple cell with a nucleoid region, surrounded by cytoplasm and a cell wall

44. Bacteria • comprised of specific shapes • rod or bacilli • spherical or cocci • spiral Rod shaped bacteria Spherical shaped cocci Spiral shaped bacteria

45. Bacteria • bacterial cells multiply by binary fission • one cell divides into two cells, identical to original Binary fission of protozoa E. Coli undergoing division

46. Bacteria • cell walls contain peptidoglycan, which is unique to bacteria cells

47. Archaea • Archaea means ancient • Archaea bacteria look identical microscopically to members of the Bacteria domain • chemical composition of cell wall differs: Archaea do not have peptidoglycan Bacteria in a Deep Sea vent

48. Archaea • have the ability to grow in extreme environments • extreme temperatures: hot or cold • acidic or alkaline conditions • extreme salt concentration Hotsprings at Yellowstone

49. Eucarya • all members of the living world except the prokaryotes are considered Eucarya • single celled and multi-celled • contain organelles • membrane bound nucleus

50. Eucarya • include • algae • fungi • protozoa Algae Fungi Ciliated protozoan