PS 22-81 - Using microbial ecology enrichment techniques to enhance ecological thinking by undergraduate students

Tuesday, August 8, 2017
Exhibit Hall, Oregon Convention Center
Debra L. Wohl, Biology, Elizabethtown College, Elizabethtown, PA

Ecosystems such as hot springs, thermals vents, salt lakes, and sewage treatment are often highlighted when teaching students about microbial diversity and ecology. This focus on more extreme ecosystems often limits students’ thinking about the role of microorganisms and the ecological principles that apply to them in more mundane everyday environments. This ecology education-based project was designed to increase students’ understanding of microbial diversity and ecology through the use of enrichment techniques. Students participating in this project were primarily undergraduate students enrolled in Microbial Ecology & Diversity (Bio335) having had a general microbiology course, but no previous ecology course. At the beginning of the semester, students were taught about enrichments (i.e., creating environmental conditions that optimize the growth of select organisms) and given a diversity workbook with a list of 20 diverse microorganisms they needed to isolate during the semester. Student worked together in pairs to apply their understanding of microorganisms, environmental conditions, and microbial interactions to enrich and isolate the organisms.


Over the course of the semester, students learned how to prepare simple media, collect samples for enrichments (e.g., pond sediment, rabbit feces, grass and soils, food), and apply their ecological understanding to create conditions that encouraged microbial growth. The majority of student pairs were able to collect 18 of the 20 assigned microorganisms. The project revealed that students gained confidence in their own ability to apply lecture material to field sampling and lab techniques. Student feedback also indicated they gained a stronger understanding of ecological concepts including concepts such as niche theory, microhabitats, richness, and evenness. By encouraging students to make a microbial collection using enrichment techniques, students applied ecological thinking to their understanding of microbial diversity and ecology. Future offerings of this project will require students to create a digital diary to include photo-documentation and critical analysis of their procedures used for successful enrichments.