Microbiology Notes

Intro to Microbiology

Microbiology

  • Study of microorganisms (bacteria, algae, protozoans, fungus, helminthes, virus).
  • Microorganisms are too small to see with the naked eye; magnification is required.

Microbes and the Planet

  • Two basic cell types:
    • Eukaryotic: nucleus, organelles, bigger.
    • Prokaryotic: no nucleus, no organelles, smaller.
    • Only bacteria are prokaryotic.
  • Microbes exist everywhere, even in places where other organisms cannot survive.
  • Ecology: bacteria recycle nutrients (decomposers).
  • Photosynthesis: some bacteria and protozoans use the sun to make food; oxygen producers.
  • Microbes produce gases (CO2, NO, CH3) that regulate Earth's temperature.

Microbes and Humans

  • Historical uses: bread, alcohol, cheese, antibiotics.
  • Biotechnology: using microbes (bacteria, yeast) in industry (cloning, GMO foods, medicine production).
  • Bioremediation: using microbes to clean up the environment (heavy metals, radiation, toxic waste).

Microbes Harming Humans

  • Pathogens: microbes that cause disease.
  • Emerging diseases: AIDS, Hep. C, Mad Cow, West Nile, Zika, COVID-19, MERS, SARS.
  • Drug resistant bacteria: MRSA, TB.
  • Super Bugs: H1N1.

History of Microbiology

  • Robert Hooke:
    • Discovered the "Cell".
  • Anton Van Leeuwenhoek:
    • First to describe microorganisms.
  • Miasma Theory: the belief that sick or dying people exude a miasma; if it gets on/in you, you die too.
  • Spontaneous Generation: The belief that non-living things can give rise to living things.

Louis Pasteur

  • Discovered fermentation.
  • Invented pasteurization.
  • Proposed the Germ Theory of Disease.
  • Invented the Swan-necked flask.
  • Vaccine for chicken cholera.
  • Vaccine for anthrax.
  • Human vaccine for Rabies.

Robert Koch

  • Developed Koch’s Postulates.
  • Proved the Germ Theory of Disease.
  • Invented heat fixed slides.
  • Invented the Simple Stain technique.

Other Important Figures

  • Joseph Lister: Aseptic Technique in surgery.
  • Ignaz Semmelweis: Hand Washing before surgery.

Taxonomy

  • Science of categorizing and naming unknown organisms.
  • Binomial system uses:
    • Genus (capitalized)
    • Species (lowercase)
  • Italicized or underlined.
  • Example: Bacillus subtilis, Staphylococcus aureus.

Viruses

  • Viruses can infect any cell type.
  • Non-living and non-cellular.
  • No metabolism of their own, requiring a host cell for replication.
  • Not killed by antibiotics.

Microbes and the Planet

  • Ecology: Some bacteria recycle nutrients for the planet (decomposers), including nitrate, nitrite, and nitrogen gas (Nitrogen Fixers).
  • Photosynthesis: Some bacteria and protozoans can use the sun to make their own food, acting as Oxygen Producers.
  • Microbes in the air, soil and water produce gases such as CO2, NO, and CH3 that help regulate the temperature on earth.