1. The Main Themes of Microbiology
Chapter 1

2. The Scope of Microbiology
Section 1.1
The Scope of Microbiology

3. Microbiology
Specialized area of biology that deals with organisms too small to be seen with the naked eye
Microorganisms or microbes
Germs, viruses, or agents
“Bugs”

4. Major Groups of Microorganisms
Bacteria
Algae
Protozoa
Helminths
Fungi
Viruses: non-cellular, parasitic, protein-coated genetic elements

5. Study of Microbes is Easy AND Difficult
Reproduce rapidly, large populations can be grown in the laboratory
Can’t be seen directly, must be analyzed through indirect methods in addition to using microscopes

6. Aspects of Microbiological Study
Medical Microbiology
Public health Microbiology and Epidemiology
Immunology

7. Aspects of Microbiological Study
Industrial Microbiology
Agricultural Microbiology
Environmental Microbiology

8. Check Your Understanding
What types of organisms are considered microbes? Provide some examples of these organisms.
What types of cells can viruses infect?
List and describe three branches of microbiology. Identify professions that make use of microbiology.

9. The Impact of Microbes on Earth: Small Organisms with a Giant Effect
Section 1.2
The Impact of Microbes on Earth: Small Organisms with a Giant Effect

10. The Impact of Microbes on Earth
Microbes have shaped the development of the earth’s habitats and the evolution of other life forms for billions of years
Single-celled organisms arose 3.5 billion years ago
Bacteria, archaea, and eukaryotes arose from this ancestor

11. Types of Cells Eukaryotes: true nucleus Prokaryotes: “pre” nucleus
Cells with a nucleus are classified as eukaryotes
Prokaryotes: “pre” nucleus
Bacteria and archaea do not have a nucleus and have been traditionally classified as prokaryotes
This classification is no longer used because bacteria and archaea are so distinct genetically

12. Bacteria are Ubiquitous
Can be found:
Deep in the earth’s crust
Polar ice caps
Oceans
Inside the bodies of plants and animals

13. Photosynthesis
Involved in the flow of energy and food through the earth’s ecosystems
Photosynthetic microorganisms account for more than 70% of the earth’s photosynthesis
Production of oxygen by oxygenic photosynthesis evolved later allowing a diversification of species

14. Decomposition Breakdown of dead matter and wastes
Accomplished by bacteria and fungi

15. Microbes Are Vital In Shaping Earth
Microbes are the main forces that drive the structure and content of soil, water, and atmosphere
Gas production by microbes
Microbes living within the earth’s crust
Bacteria and fungi living in complex associations with plants

16. Check Your Understanding
Describe the difference between a prokaryote and a eukaryote.
Describe the role and impact of microbes on the earth.
Describe the basic tenets of the Theory of Evolution.
True/False: Microscopic organisms produce more oxygen than plants.
True/False: More than 50% of the microbes on the planet live below the Earth’s crust.

17. Section 1.3
Human Use of Microbes

18. Importance of Microbes to Humans
Humans have been using microorganisms for thousands of years to improve life and even shape civilizations
Yeast for production of bread, wine, and beer
Other fungi used for cheese production
Moldy bread used in Egypt to treat wounds

19. Uses for Microbes Biotechnology Genetic Engineering
Manipulation of microorganisms to make products in an industrial setting
Genetic Engineering
Manipulates the genetics of microbes, plants, and animals for the purpose of creating new products and genetically modified organisms (GMOs)

20. Uses for Microbes Recombinant DNA technology: Bioremediation:
Techniques that allow the transfer of genetic material from one organism to another and deliberately alter DNA
Bioremediation:
introduction of microbes into the environment to restore stability or to clean up toxic pollutants

21. Check Your Understanding
Name three products produced by genetically modified organisms that benefit humans.
Describe one method in which microbes are used for bioremediation.

22. Infectious Diseases and the Human Condition
Section 1.4
Infectious Diseases and the Human Condition

23. Pathogen
Any agent (virus, bacterium, fungus, protozoan, or helminth) that causes disease
Nearly 2,000 different microbes cause disease

24. Combating Infectious Diseases
New (emerging) diseases as well as older (reemerging) diseases are increasing
AIDS, hepatitis C and viral encephalitis
Polio, leprosy, and parasitic worm diseases have largely been eradicated

25. Knowledge of Diseases Is Improving
Certain diseases once considered noninfectious are now found to be caused by microbes
Gastric ulcers caused by Helicobacter pylori
Link between certain cancers and bacteria and viruses
Cocksackie virus has been associated with diabetes
The Borna agent has been linked to schizophrenia

26. Clinical Work Against Disease Continues
During the Golden Age of Microbiology, “obvious” diseases were characterized and cures or preventions were devised
Today, we are discovering the subtler side of microorganisms and the quiet, slow, destructive diseases they cause
An increasing number of patients with weakened immune systems are subject to infections by common microbes not pathologic to healthy people
Drug-resistant microbes also contribute to the increase in infectious disease

27. Check Your Understanding
True/False: All microbes cause disease.
Why is there a difference between the top 10 causes of death in the U.S. versus worldwide?
Name three connections between diseases considered to be noninfectious and a microbe.

28. General Characteristics of Microorganisms
Section 1.5
General Characteristics of Microorganisms

29. General Categories of Microbes

30. Bacteria and Archaea About 10x smaller than eukaryotic cells
Lack organelles: small, double-membrane-bound structures that perform specific functions
All bacterial and archaeal cells are single-celled

31. Helminthes
Not true microorganisms, but are included in the study of infectious disease:
They are transmitted similarly to bacterial diseases
The human body responds to them in the same way as it responds to bacterial diseases
Their identification requires use of microscopes to view larvae and mouth parts

32. Five Types of Microbes