1. BIOL 260-General Microbiology
Instructor: Christopher Thor
Masters Degree, Bioengineering
Bachelors Degree, Molecular Biology

2. Welcome to BIOL 260: Microbiology!
First day:
Review of Syllabus
Sign-in
Introduce the course, review course expectations
Begin with first lab
Exercise 3: Microscope Lab

3. What is microbiology?
The scientific discipline which studies microbes or microorganisms
Biology of microbes
The interaction of microbes with other microbes, the environment, and humans

4. The “Yotes” Definitions:
Prokaryote: Single celled organism, no nucleus.
Bacteria, Archaea
Eukaryote: Single or multi-celled organism, membrane bound nucleus
Algae, Protozoa, Fungi, people

5. What are examples of microbes?
Algae
Fungi
Protozoa
Bacteria
Viruses
Eukaryotes: Protozoans, Fungi, Algae, Prokaryotes: bacteria
Which are Prokaryotes are which are Eukaryotes?

6. Hierarchy

7. Types of Microbes: Algae

8. Types of Microbes: Protozoa

9. Types of Microbes: Fungi

10. Types of Microbes: Bacteria

11. Viruses, Viroids, Prions

12. Microorganisms are associated with
Disease
Cause of many epidemics in history
Bubonic plague ( )
Killed 25 million people
Small pox
Killed estimated 600 million people since 10,000 BC
Eradicated in 1979
HIV
3.1 million estimated new cases per year
5% of Sub-Saharan Population
Malaria
Small Pox

13. Bacteria are associated with
Normal microbiota (normal flora)
The bacteria that are present on our bodies

14. Bacteria are associated with
The environment
Rhizobium (the greatest bacteria you’ve never heard of)
Nitrogen fixation in the soil
Food products
Beer! Or bread, wine, sauerkraut, yogurt, cheese…
Medicines
Bacteria are “programmed” to make insulin

15. History of Microbiology
It all started with the microscope!
Zacharis Janssen (1600)
Antoni van Leewenhoek ( )
Robert Hooke (1665)

16. Zacharis Janssen’s microscope
Modeled after the telescope
Consisted of two lenses
Magnified images 3-10X

17. Leewenhoek’s microscope
20-30x magnification

18. Where do cells come from?
Spontaneous generation
Francesco Redi (1668)
Spontaneous Generation does not occur
John Needham (1745)
Spontaneous Generation does occur
Lazzaro Spallanzani (1765)
Louis Pasteur (1861)
Biogenesis
Rudolf Virchow (1858)
Living things come from living things

19. Pasteur’s flasks

20. John Tyndall questions Pasteur’s experiments
Could not reproduce Pasteur’s results
Specific growth media required
Found that there were heat resistant forms of microbes
Same year (1876) Ferdinand Cohn discovers heat resistant forms of bacteria called endospores
Spores can survive in space (Apollo Program, 1960s)
1877 Robert Koch demonstrates that anthrax caused by Bacillus anthracis

21. Major Milestones in Microbiology

22. Major Milestones in Microbiology

23. New cells need to be placed in categories
Aristotle-plant or animal kingdom
Kingdom Protista (1866)
Electron microscope (1940’s)
Kingdom Procaryotae (1968)
Carl Woese proposed 3 Domains (1978)

24. Three Domain System

25. Prokaryotes (Single Celled)
Bacteria Domain (Eubacteria)
Peptidoglycan cell walls
Gram negative
Gram positive
Archaea Domain (Archaebacteria)
Not a peptidoglycan cell wall
Extremophiles
Methanogens
Halophiles
Thermophiles

26. Binomial system of nomenclature
Genus and species
Escherichia coli, E. coli
Both names are in italics or underlined and correctly spelled.

27. Relationship of size and resolution

28. Types of microscopes Brightfield Darkfield Phase Contrast Fluorescent
Electron

29. Microscopy-Brightfield

30. Oil has same refractive index as glass

31. Microscopy
Stained specimen
Wet mount

32. Microscopy
Stained specimen
Wet mount

33. Microscopy Electron microscopes - maximum magnification 100,000X
First TEM
First scanning (commercial 1965)
$150/sample

34. Microscopy Electron microscopes - maximum magnification 100,000X
“Color-enhanced”
First TEM
First scanning (commercial 1965)
$150/sample

35. Staining: key to visualization
Simple
Differential
Special

36. Microscopic Techniques: Dyes and Staining
Simple stains
Stains everything
Differential stains
Stain based on cellular traits
Gram stain - separates bacteria into two categories based on type of cell wall
Acid Fast Stain – Stains non-peptidoglycan containing bacteria (Mycobacteria)
Gram-positive
Gram-negative

37. Microscopic Techniques: Dyes and Staining
Simple stains
Differential stains
Gram stain - separates bacteria into two categories based on type of cell wall
Purple: Bacteria with high peptidoglycan containing cell walls
Pink: Counter stain

38. Differential Stain: Acid Fast

39. Microscopic Techniques: Dyes and Staining
Fluorescent dyes and tags

40. Special stain: Capsule Stain

41. Special stain: Endospore Stain

42. Special stain: Flagella Stain

43. Morphology of Prokaryotic Cells: Cell Shapes

44. Morphology of Prokaryotic Cells: Cell Shapes

45. Morphology of Prokaryotic Cells: Cell Groupings

46. Morphology of Prokaryotic Cells: Multicellular Associations
Biofilm containing mixed species