Introduction to Microbiology Denise Lim

Use Your Textbook Wisely 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

Some other words of advice Manage your time well Pay attention to detail Learn to be a good communicator Be professional

What is Microbiology? The study of organisms usually too small to see with the naked eye Requires a microscope Microorganisms include: Bacteria, archaea, fungi, protozoa, algae, viruses, and animal parasites

How small is small?

Why do we care about microbes? 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

Binomial nomenclature (naming microorganisms) Two names: Genus and species Always italicized or underlined Genus name: Always capitalized Usually a noun Species name: Always lower case Usually an adjective, sometimes a proper noun

All living organisms are either prokaryotes or eukaryotes Refers to arrangement of genetic material (DNA) in cells Pro - karyote means “before” nucleus Eu - karyote means “true” nucleus Prokaryotes have DNA spread throughout cytoplasm Eukaryotes have DNA within a membrane bounded nucleus

Prokaryotes vs. Eukaryotes Prokaryotes are either bacteria or archaea All are single-celled organisms Most are much smaller (100 - 1000X smaller) than eukaryotic cells Eukaryotes are everything else: Fungi, protistans, plants and animals Can be either single- or multi-celled organisms

Bacterial cell on left is 1000X smaller than eukaryotic cell on right

Size Comparison of two prokaryotes & a eukaryote Epulopiscium: 700 µm Escherichia coli: 0.5 - 2 µm Eukaryote Paramecium: 50 µm

Are viruses living? Bacterial Virus (T4) Animal Virus (Ebola)

Why are viruses nonliving? Noncellular Composed of genetic material (either DNA or RNA) surrounded by a protein coat No metabolic capabilities Cannot reproduce independently No ability to regulate or respond to environment

What features define life? Complex organization composed of cells Ability to grow and develop Ability to convert energy for own use Ability to reproduce genetically similar offspring Presence of genetic material: DNA & RNA Ability to regulate internal environment (homeostasis) Ability to respond to environmental stimulus

Important Historical Events: 1600's & 1700's Development of the Microscope Animicules visualized Discovery of immunization & vaccines

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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

Application of Koch’s Postulates

1900's Discovery of penicillin and other antimicrobial agents

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”