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

1. 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

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

3. 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

4. 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

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

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

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

8. Golden Age of Microbiology 1857 - 1914
rapid advances in the science of microbiology
fermentation and pasteurization
germ theory of disease
Fermentation Process In Lab

9. Fermentation & Pasteurization
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

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

11. Germ Theory of Disease proof that bacteria caused disease
Robert Koch 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

12. 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

13. 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

14. 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

15. 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

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

17. 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.

18. 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

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

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

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

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

23. 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

24. 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

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

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

27. Microorganisms as Decomposers
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

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

29. Microorganisms and Food Production
used in the production of food

30. Pharmaceuticals microorganisms
used in the development and production of pharmaceuticals

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

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

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

34. 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

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

36. 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

37. 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

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

39. 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.

40. Microbial Size

41. 3 Domains of all living organisms
Bacteria
Archaea
Eucarya

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

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

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

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

46. 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

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

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

49. Eucarya
include
algae
fungi
protozoa
Algae
Fungi
Ciliated protozoan

50. Prokaryotic & Eukaryotic Cells
notice the additional structures found in the eukaryotic cell

51. Microbial World bacteria archaebacteria algae fungi protozoa virus
viroids
prions

52. Bacteria
E. coli

53. Fungi

54. Algae

55. Protozoa

56. Viruses

57. Virus considered acellular, non-living
made up of a core containing DNA or RNA surrounded by a protein coat
can reproduce only by using the cellular mechanism of another cell
often considered the parasites of the microbial world

58. Viroids viroids single piece of nucleic acid with no protein coat
only capable of causing plant diseases
Pear blister canker viroid

59. Prions prions contain only protein
causative agent for some neurodegenerative diseases in humans and animals
Prion