Deconstructing Microbiology

By Jennifer Stearns, Michael Surette

Microbiology involves studying microorganisms from many different angles. Each perspective uses a different set of tools, from an ever-improving and changing toolbox. These include the following:

  • Morphology: The study of the shape of cells. It is analyzed using stains and microscopy.

  • Metabolism: How an organism gets energy from its environment and the waste it produces as a result. Metabolism is studied using principles from biochemistry.

  • Growth: How an organism, well, grows. The growth of a microbe is used to see how quickly the population can divide and help to distinguish between one microbe and another. Growth is measured using principles of physics, as well as good old-fashioned counting. Qualitative measures of how growth looks are also important.

  • Genotype: The genetic makeup of a microbial strain. Genes are studied using genetics, which has recently begun to involve a lot of molecular biology.

  • Phenotype: The name of the observable traits of a microbe. A phenotype is due to the interaction between the constellation of genes and environmental factors. It’s used to describe a microorganism and to study the function of genes. To measure a phenotype, you have to use some microbiology know-how to see changes in growth and metabolism, as well as other biochemical processes for communication and defense.

  • Phylogeny: The history of the evolution of microorganisms. Phylogeny is important not only because it helps us identify newly discovered microbes but also because it allows us to see how closely related different microbes are to one another. The study of a group’s phylogeny involves genetics and molecular biology, as well as evolutionary biology.

When you put all the pieces back together again, you have the science of microbiology. Microbiologists are some of the most creative scientists out there — they have many tools at their disposal that they can use in a variety of ways. The trick is to think up sneaky ways to study microbes, which is why the field is always evolving.

The term microbiology is often used to mean the study of mainly bacteria and archaea because the study of other microbes are specialties of their own. For example, the study of viruses is virology, the study of fungi is mycology, and the study of algae is phycology.