Course Hero Logo

Microbial Ecology



Microbial ecology is the study of the relationships between microbes, other organisms, and their environment. Microbes are microorganisms—life-forms that are too small to be seen without magnification—and include bacteria, protozoa, viruses, fungi, and algae. The relationships between microbes and other organisms are complex and varied. Movement and cycling of nutrients in ecosystems around the world are controlled at key points by microbes. These microorganisms are studied extensively both in and out of the lab, and their myriad roles in ecosystems are better understood every day. Human health is affected not only by pathogenic microbes but also by the vectors that spread them and by the many nonpathogenic species that alter their transmission and colonization.

At A Glance

  • Microbes are everywhere, and microbial ecology is the study of relationships among microbes, their environment, and other organisms.
  • An ecosystem is a collection of organisms together with their surrounding physical and chemical environment that makes up their habitat and includes all of the interacting relationships among organisms.
  • Biogeochemical cycles describe the flow of essential chemical elements and energy through biological and geological pools.
  • Carbon is synonymous with life on Earth, and the biogeochemistry of this element is largely contingent upon its ubiquity in the molecules that make up the bulk of living organisms.
  • Water is essential for all life, and its constant movement and flow around Earth, as well as to and from the atmosphere, is described by the hydrologic cycle.
  • Nitrogen is a major component of biological systems, and its cycling through the biosphere is dependent on several microbial transformations.
  • Metagenomics allows for the direct genetic analysis of microbial genomes contained within an environmental sample.
  • Human diseases and their spread can be affected by environmental factors, and ecological epidemiology is the study of the relationships among infectious pathogens, their hosts, and environmental factors that influence the spread of the pathogens.