Taking Methane Readings

Author: Isabella Reimer | Major: Biology | Semester: Spring 2025

Isabella Reimer is an honors student in Fulbright College of Arts and Sciences studying biology.

Can life exist beyond Earth-even on small, rocky asteroids hurtling through space? My research, under the guidance of Dr. Timothy Kral, focuses on the question: Can methanogens grow on asteroids? Methanogens are of particular interest in astrobiology because they don’t require oxygen and produce methane, which is a potential biosignature for life on other planets. As a matter of fact, Dr. Kral’s lab has demonstrated the growth of methanogens on many Martian simulants. However, nothing has ever been done with asteroid simulants. Should methanogens prove capable of survival on asteroid simulants, the field of astrobiology will be sent in an entirely new direction.

How I Got Started

I discovered Dr. Kral’s work through the university’s website and was immediately intrigued by his decades-long research on methanogens and their ability to survive in Martian-like conditions. I reached out to him directly, and he invited me to join his lab during the spring of my sophomore year. As we talked about a thesis idea, he brought up the idea of branching away from Martian simulants and exploring the idea of methanogens growing on asteroids. We then started preliminary experiments with the primary goal of determining if asteroid simulant would be toxic to methanogens or not. Through these experiments, we determined that the two asteroid simulants we used did not inhibit the growth of three different species of methanogens.

Spring Grant Term Research

During this spring semester grant term of 2025, I started working on our goal of testing the ability of asteroid simulant to sustain methanogen growth. First, fresh cultures of methanogens were centrifuged and washed with a sterile buffer, containing only sodium hydroxide and carbon dioxide, supplemented with sodium sulfoxide. The washing procedure was done three times to ensure the removal of any residual media components from the cells. Cell suspensions were then added to tubes containing asteroid simulant and buffer. The tubes were then pressurized with hydrogen gas and incubated appropriately. I then used a gas chromatograph to take methane readings weekly. Growth was observed in 15 out of the 27 tubes. Aliquots of these 15 tubes were then transferred to fresh tubes containing the same simulants. I am currently taking methane readings of these tubes every two weeks and preparing for another tube transfer soon.

What I Learned

Through this experience, I have not only learned about methanogens, but also about how scientific research is conducted from the ground up. I have gained hands-on lab experience with anaerobic techniques, such as working in an anaerobic chamber, and learned how to use a gas chromatograph. More unexpectedly, I also learned a lot about myself: I became more resilient, independent, and confident in asking questions and troubleshooting problems, both in and out of the lab. Working with methanogens wasn’t easy for me at first. Methanogens are extremely sensitive to oxygen, and even a small mistake can ruin a culture, and in the beginning, it felt like I was making many mistakes. But with persistence, note taking, and a lot of help from Dr. Kral, I improved my lab techniques. Over time, I have developed a rhythm and become more meticulous in my technique, which has ultimately led to more reliable results.

Mentorship

Dr. Kral plays a central role in my research journey. He is always available to answer questions, offer feedback, and is always patient with me. His passion for this project has cultivated an excitement in me for research. Thanks to his guidance, I’ve come to appreciate the importance of thoughtful research design, and the value of contributing to a larger scientific conversation.

What’s Next?

Although I’m planning to pursue medical school, my research experience has deeply shaped the way I think as a scientist. It has taught me to ask meaningful questions, follow the evidence, and appreciate the complexity of life—whether at the microbial level or within the human body. I hope to carry these skills into my future medical career, where curiosity, precision, and resilience will remain just as essential.