Chapter 1 - Intro

Microbiology

study of organisms too small to be observed with the naked eye

sizes of bacteria and archaea

• smallest free-living bacteria (pelagibacter ubique) - 0.4um long and 0.12um in diameter

• smallest microbe (nanoarchaeum equitans) - 0.4um in diameter

• escherichia coli (E. coli) - 4um long and 1.5um in diameter

sizes of viruses

• smallest viruses - about 10 nm (10^-9m)

• largest viruses - about 400nm (0.4 micrometers) long

Nomenclature in microbiology

standard Linnaean nomenclature with genus and species name

• Genus capitalzed and species loewr case

• in italics or underlined

• can shorten to one capital letter with a period

  • ex. E. coli

Robert Hooke

published micrographia (1665)

• pictures of molds, fungi, and other bacterial material using a compound microscope

Anton van Leeuwenhoek (1673, 1677, 1684)

wrote over 200 letters to the Royal Society of London describing observations with a simple (non-compound) microscope

Otto Muller (1786)

described 150 species of bacteria based on morphology

• said that there are different species of bacteria that do different things

Louis Pasteur (1822-1895)

• considered one of the founders of microbiology

• disproved idea of spontaneous generation

  • basically he said that cells dont just spawn

    • they come from other cells and give rise to other cells

• explained (expounded) the idea of spontaneous fermentation by microorganisms

• developed pasteurization

• developed vaccines

• supported the “germ theory” of disease

pasteurization

heating up bacteria for a period of time to kill it

• makes wine stable

• ex. removing bacteria from milk (to prevent getting tuberculosis)

Robert Koch

identified the causes of tuberculosis, cholera, and anthrax

• supported the idea of infectious disease through his experiments

Koch’s postulates

1. microorganism must be found in all organisms suffering from the disease but not in healthy organisms

2. microorganism must be isolated from a diseased organism and grown in pure culture

3. the cultured microorganism should cause disease when introduced into a healthy organism

4. microorganism must be re-isolated from the inoculated diseased organism and must be identical to the original microorganism

what is koch’s postulate used for

to prove a disease is caused by a microorganism