Introduction to Microbiology
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Introduction to Microbiology
BIO 6
Denise Lim
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Use Your Textbook Wisely
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Some other words of advice
❚  Manage your time well
❚  Pay attention to detail
❚  Learn to be a good communicator
❚  Be professional
❚  Glossary and Index
❚  Appendices
❚  "Check Your Understanding"
❚  Study Outlines
! At end of chapters
❚  Review and Study Questions at end of
chapters
! Answers in the back of the book
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What is Microbiology?
❚  The study of organisms usually
too small to see with the naked
eye
How small
is small?
! Requires a microscope
❚  Microorganisms include:
! Bacteria, archaea, fungi, protozoa,
algae, viruses, and animal parasites
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Biology 6
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Introduction to Microbiology
Why do we care about
microbes?
Binomial nomenclature
(naming microorganisms)
❚  Some can make us sick (germs)
❚  Most are beneficial
! Important part of food chain:
photosynthesis to decomposition (rot)
! Found in our bodies (probiotics)
! Fermentation: cheese, yogurt, wine,
beer, vinegar, bread
! Pharmaceuticals and medicine
❚  Two names: Genus and species
! Always italicized or underlined
❚  Genus name:
! Always capitalized
! Usually a noun
❚  Species name:
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All living organisms are either
prokaryotes or eukaryotes
! Always lower case
! Usually an adjective, sometimes a
proper noun
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Prokaryotes vs. Eukaryotes
❚  Prokaryotes are either bacteria or
archaea
❚  Refers to arrangement of genetic
material (DNA) in cells
! All are single-celled organisms
! Most are much smaller (100 - 1000X
smaller) than eukaryotic cells
- karyote means “before” nucleus
! Eu - karyote means “true” nucleus
! Pro
❚  Eukaryotes are everything else:
Fungi, protistans, plants and animals
❚  Prokaryotes have DNA spread
throughout cytoplasm
❚  Eukaryotes have DNA within a
membrane bounded nucleus
! Can be either single- or multi-celled
organisms
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Size Comparison of two prokaryotes & a eukaryote
❚  Prokaryotes
! Epulopiscium:
700 µm
! Escherichia
coli: 0.5 - 2 µm
❚  Eukaryote
Bacterial cell on left is 1000X smaller
than eukaryotic cell on right
! Paramecium:
50 µm
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Biology 6
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Introduction to Microbiology
Are viruses living?
Why are viruses nonliving?
❚  Noncellular
! Composed of genetic material (either
DNA or RNA) surrounded by a protein
coat
Bacterial Virus (T4)
Animal Virus (Ebola)
❚  No metabolic capabilities
❚  Cannot reproduce independently
❚  No ability to regulate or respond to
environment
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What features define life?
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Important Historical Events:
1600's & 1700's
❚  Complex organization composed of cells
❚  Ability to grow and develop
❚  Ability to convert energy for own use
❚  Ability to reproduce genetically similar
offspring
❚  Development of the Microscope
! Animicules visualized
! Presence of genetic material: DNA & RNA
❚  Discovery of immunization &
vaccines
❚  Ability to regulate internal environment
(homeostasis)
❚  Ability to respond to environmental stimulus
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Biology 6
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Introduction to Microbiology
1800's
❚  Development of Cell Theory
❚  Fermentation and Pasteurization
❚  Germ Theory of Disease
❚  Antisepsis and Disease
! Importance of hand washing
! Antiseptics: chemical compounds that
could kill germs
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Robert Koch 1843 - 1910
❚  Developed pure culture
techniques
❚  Proved that Bacillus
anthracis caused the
disease anthrax in cattle
! Developed Koch’s
Postulates: rules for
proving a specific microbe
caused a specific disease
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Application of Koch’s
Postulates
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1900's
❚  Discovery of penicillin and other
antimicrobial agents
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Biology 6
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Introduction to Microbiology
Staphylococcus aureus inhibition
by fungus Penicillium antibiotic
1900's
❚  DNA is the genetic molecule
❚  Genetic Code - 1960’s
❚  Central Dogma
❚  Recombinant DNA technology 1970's & 1980's
❚  Human Genome Project
❚  Personal “-omics”
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Biology 6
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