Microbial Ecology: Beginnings and The Road Forward

• Microbial Ecology


  The study of the influence of environment on microbial growth and development
• Ecosystem


  • A biological community of interacting organisms and their physical environment
• Components of Ecosystem


  • Abiotic Components
  • Biotic Components
• Abiotic Components


  Non-living or physicochemical factors like air, soil, water, and the basic compounds and elements in the environment
• Biotic Components


  Living organisms in the environment
• Levels of Biological Organization

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• Identify Microbial Species


  1. Laboratory culture and culture-independent molecular approaches

  2. Evolutionary relationships

  3. Environmental variables that dictate abundance

  4. Distribution

  5. Specific Activity
• Persistent Questions about Microorganisms in the Environment

  • Which microbes are present?
  • What is the role of each species?
  • What interactions occur in the microbial environment?
  • How do microbes change the environment?
• Roots of Microbial Ecology

  • 1683 - Antonie Van Leeuwenhock published drawings of bacteria
  • 1786 - Otto Friedrich Muller reported characteristics of 379 species
  • 1823 - Bartholomeo Bizio described "blood" drops in "bleeding" bread
  • 1837 - Friedrich Traugott Kuzing, Charles Cagniard-Latour, and Theodor Schwann published papers on microorganisms and ethanol production
  • 1838 - Christian Gottfried Ehrenberg described Gallionella Ferruginea
  • 1843 - Friedrich Traugott Kutzing described Leptothrix Ochtscea
  • 1852 - Mazimilian Perty described Chromatium species
  • 1866 - Ernst Haeckel proposed concepts of mutualistic and antagonistic symbiosis
  • 1889 - Matrinus W. Beijerinck developed enrichment technique for pure bacterial cultures
  • 1889 - Sergus N. Wompgradsky established concept of chemolithotrophy and autotrophic growth
  • 1904 - L. Hiltner studied the biology of the root zone and proposed the term rhizosphere
  • 1909 - Sigurd Orla-Jensen presented a natural system for arrangement of bacteria
• Phylogenetic tree


  A diagram that depicts the lines of evolutionary descent of different species, organisms, or genes from a common ancestor
• Phylogenies are useful for organizing knowledge of biological diversity, for structuring classifications, and for providing insight into events that occurred during evolution
• The study of microbial ecology includes the influence of environment on microbial growth and development
• Not only do physical and chemical changes in the environment select for microorganisms, but biological adaptation enables bacteria and archaea to optimize the use of nutrients available to support growth