The snow was bright and clean this January day as six students skidded down a Wyman Park trail carrying bags of centrifuge tubes. They were gathering samples in search of bacteria for the intersession class Microbe Hunting: Environmental Microbiology. This meant scraping trees, scooping snow, and balancing on river rocks to bottle icy Stony Run water to examine in the lab.

The two-week class was run by Ann Deng and Lorna Mitchison-Field, doctoral students in the Program in Cell, Molecular, Developmental Biology, and Biophysics. “I love thinking about microbes in the environment—who is there, what they are doing, how they do what they’re doing,” Mitchison-Field said. “It is immensely rewarding to be able to share that with the students.”

Learning scientific thinking

The class was designed to help students further their scientific thinking, research, and lab skills through a self-driven project. Each group created their own research questions, ranging from whether the shape of bacteria changes how colonies grow, to whether bacteria from “human environments” like a pedestrian bridge are more antibiotic resistant than those in trees or dirt. Students had more freedom to follow their interests or change a plan than in some traditional classes. They learned how to develop scientific questions, conduct literature reviews, grow bacteria from samples in agar plates, get comfortable with an array of lab techniques, and troubleshoot issues. The small cohort and concentrated syllabus meant they mastered a lot in a short period.

This resulted in some fun discoveries. One group found a series of bacteria that somehow “caged” themselves into non-moving borders. Another found that a lot of their bacteria was really fungus and had to pivot and isolate new samples—which ended up growing vibrant, purple colonies. 

“I like how this class was exploratory—you could really just do anything,” said Halima Ibrahim, a sophomore molecular and cellular biology major. “Even though the main focus was the bacteria, being able to see myself in a different light through the project was really nice.”

Students are led through the snow-covered woods in search of samples.

A student scrapes the rust-covered bridge for a sample.

Student Ten Nazur scrapes the base of a fallen tree.

Students Sara Kaufman and Sophia Baleeiro gather samples from an area of frozen water.

Students gather samples from frozen Stony Run.

Multiple agar plates hold microbe samples.

Sophia Baleeiro writes notes on the findings from each sample.

Ann Deng and Lorna Mitchison-Field look over a microscope.

A student swipes samples onto an agar plate.

Ann Deng and Halima Ibrahim look at the samples in a microscope.

Ann Deng, Lorna Mitchison-Field, and students work together on their projects.

The importance of microbes

Sophia Baleeiro, a sophomore majoring in environmental science and political science, was happy to get wider microbiology lab experience. As an athlete, she doesn’t always have mental or physical time to take labs during the semester. She’s personally interested in Baltimore’s environment and its impact on health, and this class let her explore another side of that. Students also appreciated getting a new viewpoint of their surroundings. “I like to go to Wyman Park a lot just to hike and take a break,” said biomolecular engineering sophomore Sara Kaufman. “It’s neat to see what’s actually [living] there.”

“I hope this class helps students develop an inherent interest in the biology of microbes—not just in their utility as decomposers and their threat as pathogens, but in how the rules of life operate on these tiny organisms,” Deng said. “This is important for understanding the current strengths and shortcomings of the field of biology as a whole, and hopefully it will inspire students to connect biological questions to their daily lives.”