Chapter 1: History of Microbiology

• Microbiology


  Study of organisms and agents too small to be seen by the naked eye (<1mm)
• Microbiology


  The study of organisms that can exist as single cells (others are acellular), contain a nucleic acid genome for at least some part of their life cycle, and are capable of replicating that genome
• Microorganisms


  • Acanthurus lineatus, the striped sturgeonfish
  • Thiomargarita namibiensis
• The Science of Microbiology

  • Understanding the living world of microscopic organisms (as a basic biological science)
  • Applying our understanding of microbial life processes for the benefit of humankind and planet Earth (as an applied biological science)
• Importance of microorganisms


  • First living organisms on planet
  • Live everywhere
• Scope and Relevance of Microbiology

  • Importance of microorganisms
  • Fungi
  • Algae
  • Protozoa
  • Bacteria
  • Viruses
• Microorganisms were the first living organisms on the planet
• Microorganisms live everywhere life is possible
• Microorganisms are more numerous than any other kind of organisms
• The global ecosystem depends on the activities of microorganisms
• Microorganisms influence human society in many ways
• Basic Microbiology


  • Virology: viruses
  • Mycology: fungi
  • Phycology: algae
  • Protozoology: protozoa
  • Bacteriology: bacteria
• Applied Microbiology


  • Medical Microbiology
  • Immunology
  • Public Health Microbiology
  • Food & Dairy Microbiology
  • Industrial Microbiology
  • Agricultural Microbiology
  • Microbial Ecology
• Fields of Applied Microbiology

  • Infectious diseases
  • New and improved industrial processes
  • Renewable resources
  • Microbial ecology and diversity
• Microorganisms were discovered through history
• Microbiology has a brief history
• Ötzi the Iceman was infected with Trichuris trichiura and possibly Borrelia burgdorferi
• Ötzi may have tried to treat his infections with the woody fruit of the Piptoporus betulinus fungus
• Ancient Greeks attributed disease to bad air, mal’aria, which they called “miasmatic odors”
• The Romans believed in the “miasma” hypothesis and created a sanitation infrastructure
• The Romans built aqueducts and a giant sewer, the Cloaca Maxima, to deal with waste
• Antonie van Leeuwenhoek observed "wee animalcules" in 1676
• Robert Hooke invented the simple compound microscope in 1665 (30x magnification)
• Athanasius Kircher suggested to be the first to observe microorganisms, 20 years before Hooke's observation and 29 years before van Leeuwenhoek
• Athanasius Kircher: '“who would believe that vinegar and milk abound with an innumerable multitude of worms.”'
• Athanasius Kircher: '“putrid material is full of innumerable creeping animalcule”'
• Spontaneous Generation Theory: Life emerges from non-living matter; "vital force" required
• Biogenesis Theory: "Life begets life"
• Francesco Redi (1668) conducted experiments to disprove Spontaneous Generation Theory
• John Needham (1745) observed growth of microorganisms in sealed mutton broth
• Lazzaro Spallanzani (1768) showed that air was required for the vital force to work in Spontaneous Generation Theory
• Franz Schultze and Theodor Schwann passed air through strong acids and red-hot tubes respectively to prevent microbial growth
• Georg Friedrich Schröder & Theodor von Dusch (1850) filtered air through sterile cotton wool to prevent microbial growth
• Louis Pasteur (1822-1895) is known as the "Father of Modern Microbiology"
• Louis Pasteur's experiments with swan-neck flasks proved that life did not arise from non-life
• Pasteur’s experiments


  • Pasteur’s test of spontaneous generation: By sterilizing a food source and keeping it isolated from the outside, Pasteur observed no putrefaction of the food source (top panel). Upon exposure to the outside environment, Pasteur observed the putrefaction of the food source (bottom panel). This strongly suggested that the components needed to create life do not spontaneously arise. Louis Pasteur’s experiment illustrates the fact that the spoilage of liquid was caused by particles in the air rather than the air itself. These experiments were important pieces of evidence supporting the idea of germ theory of disease
• John Tyndall (1820-1893) demonstrated that dust carries microorganisms
• John Tyndall (1820-1893) provided evidence for the existence of exceptionally heat-resistant forms of bacteria
• John Tyndall (1820-1893) developed the process of “tyndallization”
• Agostino Bassi (1773-1856) showed that a disease of silkworms was caused by a fungus