202 General Microbiology II

Microbial Ecology Lecture Outlines

Basic Concepts of Microbial Ecology

Ecosystem

• Habitat

• Niche

Symbiosis

• Parasitism
  • definition

  • example - infections

• Commensalism
  • definition

  • example - Clostridium

• Mutualism
  • definition

  • examples:
    • Escherichia coli

    • lichens

    • protozoan endosymbiosis

        

    • rumen ectosymbiosis

Microorganisms in Nature

Microenvironment

Surface Attachment

Nutrients

Growth Rates

Competition

Food Chain

Communication

Biogeochemical Cycles

Carbon redox cycle

• carbon reservoirs

• carbon reduction

• carbon oxidation
  • organic substrate utilization

  • competition

  • cooperation

Nitrogen redox cycle

• nitrogen reservoirs

• assimilative nitrogen metabolism
  • nitrogen fixation

  • nitrate reduction

• dissimilative nitrogen metabolism
  • nitrate reduction

  • nitrification

  • denitrification

Sulfur redox cycle

• sulfur reservoirs

• sulfur oxidation

• sulfur reduction
  • dissimilative sulfate reduction

  • assimilative sulfate reduction

Iron redox cycle

• iron oxidizing bacteria

• iron reducing bacteria

Resource Utilization and Succession

Terrestrial Habitats

Soil formation and characteristics

• soil formation

• soil characteristics

Plant-Microbe Interactions

• rhizosphere
  • bacterial associations
    • Rhizobium or Bradyrhizobium
      • symbiosis establishment

      • basis of symbiosis

    • Frankia

    • free-living nitrogen-fixing bacteria

  • fungal associations

  • tripartite associations

• phyllosphere
  • ice-nucleating activity

  • plant infections
    • plant disease resistance

    • crown gall disease

Aquatic Habitats

Typical organisms

• phototrophs

• chemotrophs

Productivity in various aquatic environments

• oceans

• lakes

• rivers

Disruption of aquatic environments

• eutrophication

• thermal stratification

• oxygen stratification

Environmental Applications

Wastewater (including sewage) treatment

• primary treatment

• secondary treatment
  • aerobic decomposition processes

  • anaerobic decomposition process

• tertiary treatment

Drinking Water

• derivation

• purification

• indicators of fecal contamination

Impact of Metals on Microorganisms

Biodegradation

• natural products
  • petroleum

  • biodegradable plastics

• xenobiotics
  • PCBs

  • PAHs

  • pesticides

Extreme Habitats

Variables

Yellowstone National Park

Deep-sea environment

• Deep-sea floor

• Hydrothermal vents

Antarctic Environments