Day 1 of any microbiology course is a discussion of what is microbiology. The simple definition is "the study of microorganisms", but on further reflection, this definition really isn't all that simple. Two questions come from this definition: 1. what are microorganisms and how do we study them?
Microorganisms or microbes are organisms that can only be seen with a microscope. Thus, microbiology is the study of microscopic organisms. Well, sort of. Microbiologists study both cellular organisms like bacteria, algae, protozoa and fungi, but also acellular entities like viruses, prions and viroids. Since viruses are acellular and the cell is the basic unit of organisms, viruses are not organisms but they are microscopic.
The cellular organisms can be divided into two groups based on their structure: prokaryotes and eukaryotes. Bacteria are prokaryotes, while algae, protozoa and fungi are eukaryotes. Not all of the eukaryotes are microscopic. You have probably seen mushrooms growing in the woods or on your lawn for example. Microbiologists still claim fungi as part of their territory, however, since some fungal species are microscopic.
The Microbe World has a photo gallery of a few different types of microorganisms here, if you would like to put a picture to a name.
Since a microscope is necessary to see microorganisms, you are probably guessing that the microscope plays a big role in microbiology. For some microbiologists, yes, but for others no. In my graduate studies, the only time I saw I microscope was when I was teaching introductory microbiology courses. My research used molecular techniques to learn about how bacteria were resistant to antibiotics. There are numerous techniques used to study microbiology but the scientific method is the basis for all study. I will explain techniques as necessary in future blog posts.
An awesome introduction to microbiology is found in this video, "Initimate Strangers: The Unseen Life on Earth" Watch the first episode "The Microbial Universe" for more information on the scope of microbiology.
So as you can see, the definition of microbiology is just the beginning for a more complicated journey that I started 20 years ago and still feel like I have a lot to learn. I'm glad that you are sharing that journey with me.