1. causing disease and causing food spoilage
Microbes help us by
decomposing organic waste
performing photosynthesis
producing ethanol, acetone, vinegar, cheese, bread, . . .
producing insulin and many other drugs
Microbes harm us by
causing disease and causing food spoilage
Microbes harm us by causing disease and causing food spoilage

2. Naming and Classifying Microorganisms
Carolus Linnaeus established the system of scientific nomenclature in 1739.
Each organism has two names  Binomial nomenclature: Genus + species
Italicized (or underlined), genus capitalized, “latinized”, used worldwide.
Portrait of Carl Linnaeus at 32 by J. H. Scheffel. Oil Painting, Reproduction courtesy Uppsala University Art Collections
Scientists around the world are celebrating the 300th anniversary of the birth of Swedish botanist Carl Linnaeus. He is best known for instituting a two-name method for identifying plants and animals, called binomial nomenclature. Considered the “father” of modern taxonomy, Linnaeus named approximately 4,400 species of animals and 7,700 species of plants.

3. Examples Staphylococcus aureus (S. aureus) Escherichia coli (E. coli)
Streptococcus pneumoniae (S. pneumoniae)
1857 –1911
Staphylococcus aureus: Describes the clustered arrangement of the cells (staphylo-) and the golden color of the colonies (aur-).
E. coli: Honors the discoverer, Theodor Escherich, and describes the bacterium’s habitat–the large intestine or colon.

4. Types of Microorganisms
Bacteria
Archaea
Fungi
Protozoa
Algae
Viruses
Multicellular animal parasites
Prions

5. Bacterium / Bacteria Prokaryotic Peptidoglycan cell wall
Reproduction by binary fission
Gain energy from use of
organic chemicals
inorganic chemicals or
photosynthesis

6. Archaea Prokaryotic No peptidoglycan Live in extreme environments
Include
Methanogens
Extreme halophiles
Extreme thermophiles
Figure 4.5b

7. Fungus/Fungi Eukaryotic Chitin cell walls
Use organic chemicals for energy.
Molds and mushrooms are multicellular consisting of masses of mycelia, which are composed of filaments called hyphae.
Yeasts are unicellular.

8. Protozoan/ Protozoa Eukaryotes Absorb or ingest organic chemicals
May be motile via pseudopods, cilia, or flagella

9. Viruses Are acellular Have either DNA or RNA in core
Core is surrounded by a protein coat.
Coat may be enclosed in a lipid envelope.
Viruses only replicate within a living host cell.

10. Multicellular Animal Parasites
Eukaryotes
Multicellular animals
Helminths are parasitic flatworms and round worms

11. Three Domain Classification
Bacteria
Archaea
Eukarya
Protista
Fungi
Plants
Animals