Microbiology Lecture Notes

Welcome to Microbiology

  • Class: BIOL41 Lecture 1
  • Instructor: Dr. Y
  • Date: April 7, 2025

Road Map

  • Introductions & Welcome
  • Syllabus: unique points
  • Short break
  • Intro to Microbiology
  • Summary & Exit Ticket

Class Introductions

  • Icebreaker Activity: Students introduce themselves using the following prompts:
    • Names and pronouns
    • Interest in the course
    • A surprising fact about themselves
    • Exchange contact information
  • Guess that Microbe Game: Match photos to the correct microbial types:
    • C. elegans (worm)
    • Ebola (virus)
    • Borrelia burgdorferi (bacteria)
    • Spaghetti pasta
    • Stemonitis (slime mold)

Important Concepts in Microbiology

Big Questions Addressed in Class
  • Importance of microbiology in daily life
  • Identification of bacteria, fungi, and viruses
  • Distinction of microbes under a microscope
  • Challenges in treating viruses
    • Understanding viral mutations and variants
    • Case study: COVID-19
  • Human immune response to infections

Learning Goals

  • Understand microbes and their impacts on human health
  • Explore how microbes interact with drugs
  • Learn methods humans use to combat microbial threats

Microbiome and Microbial Diversity

Tree of Life
  • Microbes fit into two primary categories:
    • Prokaryotes: Bacteria and Archaea
    • Eukaryotes: Fungi, Protozoa, Algae, Multicellular Animal Parasites
    • Viruses: Classified as non-living
Key Differences Between Archaea and Bacteria
  • Both are single-celled and lack a nucleus or mitochondria
  • Archaea are more genetically similar to eukaryotes than bacteria
  • Bacteria exhibit greater genetic diversity

Microorganisms: Friend or Foe?

Microbial Relationships
  • Symbionts: Microbes providing benefits
  • Pathogens: Microbes causing harm
    • Relationships can vary:
    • Commensalism: One benefits, other unaffected
    • Mutualism: Both benefit
    • Parasitism: One benefits, other harmed
Human Microbiome
  • Composition:
    • Approx. 101410^{14} microorganisms in the human body
    • Contains 20,000−25,00020,000 - 25,000 human genes
    • Microbial genes: 9,000,0009,000,000

Environmental Adaptation and Microbial Diversity

Microbial Adaptations
  • Microbes thrive in extreme environments
  • Energy sources:
    • Organic compounds
    • Various inorganic sources (e.g., CH<em>4CH<em>4, H</em>2SH</em>2S)
Human Uses of Microbes
  • Food Production: Yogurt, kimchi, sauerkraut, cheese
  • Environmental Applications: Wastewater treatment, bioremediation
  • Medicine: Insulin production, vaccines

Healthy Microbiomes

Role in Health
  • Prevent pathogenic infections
  • Impact mood and behavior through gut microbiota
  • Process carbohydrates and regulate bodily functions
  • Majority of microbes are beneficial (< 1% pathogenic)

Microbial Relationships with Hosts

  • Mutualism: Both organisms benefit
  • Commensalism: One benefits, other unaffected
  • Parasitism: One benefits at the expense of the other

Conclusion & Exit Ticket

  • Insight Reflection:
    • Summarize a key insight in your own words
  • Questions for Further Discussion:
    • Identify confusions or topics needing more exploration