Laboratory Investigations in Microbiology

Course Home | Lab Manual Home

Chapter 37: Mystery Microbe

Microbes are encountered by us every day and every place you go! You rarely get to see these (obviously, they are microscopic), and most people would be amazed to find out just how abundant and wide-spread they are. Throughout this semester, you will have the opportunity to culture microbes from different sources (human body; food; soil; water; surfaces), and while we can take a good guess as to their identity, we often don't figure them out. This mystery microbe project will give you an opportunity to find, grow, and identify one microbe down to the species level (hopefully).


This project will begin on the first day of lab, where everyone will be invited to sample one source of microbes of their choice. You are virtually guaranteed to find many bacteria in each place! Once cultured (Chapter 1), you will then be allowed to make a long-term agar culture (slant - Chapter 7) and begin the process of identifying it alongside each lab's regularly scheduled protocols:

Stain and view the microbe (Chapter 5); culture the microbe (Chapter 7); characterize its metabolic abilities (Chapters 15-19)

This will give you a profile of the microbe. Complete the Mystery Microbe Report form and attach pictures to it.

What is my Mystery Microbe's identity?

Good question! Do you have enough information to positively identify this microbe? The shape, colony appearance, Gram stain, and biochemical traits will give you many clues, but is this enough? Possibly - at least to take a good guess as to the Genus. If you want to truly know what it is, however, you will need to get its DNA sequence! We will use a DNA sequencing service to send samples and get the 16S rRNA gene sequence identification.


© 2003 - 2022 Josť de Ondarza, Ph.D.