Intro micro

Page 1

Page 2: Early Development of Microbiology

• Chapters Overview:

  • Taxonomy (Ch. 1)

  • Microbes (Ch. 2)

  • The Microscope (Ch. 3)

  • Associations Between Organisms (pg. 237-138)

• Bacterial Shapes (Ch. 4)

• Lab Exercises

  • Important Key Terms:

    • Clear: Indicates no bacteria growth.

    • Cloudy: Indicates bacteria growth.

    • Sterile: Free of all live forms.

Page 3: The Microbial World

• Microbiology Definition: Study of microscopic organisms found everywhere (in air, water, and food).

• Importance of Microbes:

  • Essential for various life processes, including digestion (e.g., probiotics).

  • Can produce substances such as insulin, antibiotics, hormones, and amino acids.

  • Decomposers: Breakdown organic material, recycling nutrients in ecosystems.

• Classification of Microbes:

  • Harmful:

    • Agents of food spoilage and diseases (etiological agents).

  • Useful:

    • Essential in various biological and industrial processes.

• Historical Background:

  • Aristotle (346 BC): Proposed spontaneous generation of life.

  • Francesco Redi (1665): Disproved spontaneous generation through experiments.

  • Antonie van Leeuwenhoek (1673):

    • First to observe microorganisms using a microscope he constructed; known as the "Father of Microbiology."

  • Name Introduction:

    • Christian Gottfried Ehrenberg (1825) named microorganisms "Bacteria" from the Greek word "Bakterion" meaning "small stick."

  • Louis Pasteur:

    • Disproved spontaneous generation using S-shaped flasks; highlighted the importance of sterilization.

• Germ Theory of Fermentation:

  • Fermentation: Life processes without air.

    • Nonvital: Yeast found during fermentation yields by-products.

    • Vital (Biological): Role of yeast in alcoholic fermentation demonstrated.

• Joseph Lister:

  • Development of antiseptic surgery based on germ theory.

• Germ Theory of Disease - Koch's Postulates:

  • Robert Koch (1876): Established criteria for linking bacteria to diseases.

  • Koch's Postulates:

    1. Same pathogen must be present in every case of the disease.

    2. Pathogen must be isolated from the diseased host and grown in pure culture.

    3. Pathogen from the pure culture must cause the same disease in healthy animals when inoculated.

    4. Pathogen must be isolated from the inoculated animal and shown to be the original organism.

  • Innovation: 1881 - Koch introduced a medium of gelatin-soaked broth, leading to the invention of the Petri dish by Walter Hesse, using agar as a solidifying agent.

Page 4: Early Development of Microbiology