Curricular integration of DNA analyzer promotes discovery-based learning at UCLA

Background/Question/Methods: Undergraduate science education should mirror the collaborative nature of discovery-based research and reflect how scientific hypotheses are evaluated and results are communicated in the 21^st century. Such an undertaking requires the development of teaching methods that actively engage students in the creative process of scientific inquiry, provide skills necessary for success in the modern research laboratory, as well as foster excitement about the discovery process central to scientific research. To this end, UCLA’s Department of Microbiology, Immunology, and Molecular Genetics launched a project-based laboratory course entitled ‘I, Microbiologist’ in which students explore microbial diversity within environmental samples. In a single 10-week quarter, students generate 16S ribosomal RNA gene data sets, which they use to build phylogenetic trees, characterizing the composition of bacterial communities inhabiting soil samples collected from interesting sites in the Los Angeles area. As participants in an interdepartmental curricular initiative, students in a genomic biology course, run by the Life Sciences Core Curriculum, use the Li-Cor Biosciences DNA analyzer to sequence the samples prepared in the ‘I, Microbiologist’ course. Together, these two groups of students collaborate in an exploration of microbial diversity.

Some students in the ‘I, Microbiologist’ course target the rhizosphere of plants hypothesized to respond to the activities of nitrogen-fixing bacteria. Cultivation of microbes on media lacking a nitrogen source produces isolates that are screened for the presence of nitrogenase genes or proteins. Students in a plant biology course offered by the Molecular, Cell and Developmental Biology department investigate the role microbes play in plant development wherein they cultivate plants inoculated with putative nitrogen-fixers isolated by ‘I, Microbiologist’ students and assess the effect on plant growth. Here, students learn not only about biological nitrogen fixation, plant-microbe interactions, and root biology, but also become active participants in microbial energy research, exploring ways by which these organisms could be commercially exploited as biofertilizers.

Results/Conclusions: Taken together, this collaborative research experience represents a model for undergraduates in the life sciences to learn the process of scientific inquiry, and for educators to engender student interest and enthusiasm about research in microbial ecology and evolution.