1. Chapter 1 Humans and the Microbial World A Glimpse of History
Antony van Leeuwenhoek ( )
Dutch merchant
Skillful at grinding lenses for 300x magnification
“Animalcules”
Royal Society of London

2. 1.1 The Origin of Microorganisms
The Scientific Method
Francesco Redi
1st to show evidence that disproved the
theory of “spontaneous generation”
1.1 The Origin of Microorganisms
Theory of Spontaneous Generation
Experiment:
Positive control
Conclusion: maggots produced by
flys, not by spontaneous generation
Negative control

3. 1.1 The Origin of Microorganisms
Theory of Spontaneous Generation
Louis Pasteur
Gave final proof that the theory of
“spontaneous generation” does not
apply to microbes
“vital force”

4. 1.1 The Origin of Microorganisms
Theory of Spontaneous Generation
John Tyndall
Showed that some bacteria were not killed
by 5 min. of boiling
Bacterial endospores were present in hay
Anthrax spores

5. 1.1 The Origin of Microorganisms
Theory of Spontaneous Generation
The First Microorganisms
Progenitors of microorganisms no longer exits
Primitive Earth - high temp. and low oxygen
Astrobiology

6. 1.2 Microbiology: A Human Perspective
Vital Activities of Microorganisms
1. Microbes necessary for life as we know it
(nitrogen cycle)
(production of oxygen)
2. Biodegradation
(waste and cellulose)

7. 1.2 Microbiology: A Human Perspective
Vital Activities of Microorganisms
Applications of Microorganisms
“Biotechnology” = the application of biology to solve practical problems
and produce useful products economically
Food production
breadmaking, alcohol, milk products
Bioremediation
PCBs, DDT, oil, TNT, radioactive material
Useful products
organic substances, antibiotics, insecticides

8. 1.2 Microbiology: A Human Perspective
Vital Activities of Microorganisms
Applications of Microorganisms
Genetic Engineering
Vaccines
Use bacteria to genetically engineer plants
Use of viruses for gene therapy
Use bacteria to express certain genes and produce
products like interferon, insulin, human growth
hormone, anti-clotting factors

9. 1.2 Microbiology: A Human Perspective
Vital Activities of Microorganisms
Applications of Microorganisms
Genetic Engineering
Medical Microbiology

10. 1.2 Microbiology: A Human Perspective
Vital Activities of Microorganisms
Applications of Microorganisms
Genetic Engineering
Medical Microbiology
Past triumphs: Small pox, Bubonic plague, Polio
Present and future challenges:
Emerging diseases
Resurgence of old diseases
Chronic diseases caused by bacteria
Legionnaire’s disease
Toxic shock syndrome
Lyme disease
AIDS
Hantavirus
West Nile virus
Antibiotic resistance
Foreign travel
Reductions in vaccinations
Immunosuppression
Peptic ulcers
Arteriosclerosis
River blindness

11. 1.2 Microbiology: A Human Perspective
Vital Activities of Microorganisms
Applications of Microorganisms
Genetic Engineering
Medical Microbiology
Microorganisms as Subjects of Study
Microbes allow for easier study of the mechanisms of life
Large number of Nobel laureates are microbiologists
(back cover)
“What is true of an elephant is also true of bacteria.”
- Jaques Monod

12. 1.3 The Microbial World The Bacteria
Single-celled prokaryotes (no membranous organelles)
Varied shapes
Peptidoglycan cell wall
Divide by binary fission
May be motile (flagella)

13. 1.3 The Microbial World The Bacteria The Archaea
Single-celled prokaryotes (no membranous organelles)
Varied shapes
Do not have peptidoglycan cell wall
Divide by binary fission
May be motile (flagella)
Can grow in extreme environments

14. 1.3 The Microbial World
The Bacteria
The Archaea
The Eucarya

15. 1.3 The Microbial World The Bacteria The Archaea The Eucarya
Nomenclature
Binomial
Escherichia coli
E. coli
E. coli strain K12
E. coli strain O157 (“Jack in the Box strain”)

16. 1.3 The Microbial World
Obligate intracellular
parasites

17. 1.3 The Microbial World Size in the microbial world Epulopiscium
fishelsoni
Red surgeon fish
“guest at the banquet
of a fish”