2. Speed. The three bacteria grow quickly, and Koch’s postulates can be taught in a 2–3 week period—longer if lab classes meet once per week.
3. The three bacterial species are readily differentiated by light microscopy, colony morphologies, and differential growth on selective
4. There is a clear “disease phenotype” of peep pox: it is hydrolysis of gelatin-based candies such as marshmallow peeps and
5. This multilab protocol combines multiple techniques and can
be used to introduce or to strengthen the following core
microbiology skills: sterile technique, light microscopy, pasteurization, gelatinase test, and differential and selective
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(pp. 27–53). Washington, DC: ASM Press.
Fulton, M. M. (1981). A simple lab exercise demonstrating Koch’s
postulates. American Biology Teacher, 43, 394–396.
Hogue, R. S. (1971). Demonstration of Koch’s postulates. American Biology
Teacher, 33, 174–175.
Leboff, M. J., & Pierce, B. E. (2010). Microbiology Laboratory Theory &
Application. Englewood, CO: Morton Publishing Company.
Lennox, J. (1985). Those deceptively simple postulates of Professor Robert
Koch. American Biology Teacher, 47, 216–221.
Mitchell, J. K., Orsted, K. M. & Warnes, C. E. (1997). Fun Microbiology: Using
a plant pathogenic fungus to demonstrate Koch’s postulates. American
Biology Teacher, 59, 574–577.
Ringel, S. M. (1968). Demonstration of Koch’s postulates. American Biology
Teacher, 30, 527–528.
Sanders, E. R., & Miller, J. H. (2010). I, Microbiologist, a Discovery-Based
Course in Microbial Ecology and Molecular Evolution. Washington, DC:
JOHN L. DAHL ( firstname.lastname@example.org) is an Assistant Professor in the
Department of Biology, University of Minnesota Duluth. WAYNE GATLIN III
is an Adjunct Lecturer in the Department of Biology, Endicott College,