Conducting Research
Author: Allyson Edwards | Major: Biochemistry | Semester: Spring 2024
Life on other planetary bodies has been a topic of great interest to scientists for years with Mars in particular being heavily discussed within the scientific community. Throughout the past few years, I’ve been studying the potential of life on Mars under my mentor, Dr. Timothy Kral. Dr. Kral’s lab investigates the possibility of microorganisms called methanogens living within the subsurface of Mars. Studying the growth of these organisms can allow us to draw some interesting conclusions regarding the possibility of life on Mars.
There are a few reasons why methanogens are well-suited for this type of project. Firstly, methane has been detected in the atmosphere of Mars, leading to a large pool of theories regarding possible origins of this methane. Methanogens are anaerobic and utilize inorganic chemical energy to grow, engaging in a process called methanogenesis. This results in the production of methane.
They are also extremophiles who thrive in harsh conditions. The surface conditions of Mars are too deadly for methanogens to exist, but the subsurface areas of Mars may contain important elements such as liquid water, molecular hydrogen, and carbon dioxide. Given that these nutrients are the simplest components required for methanogen growth, the subsurface may be hospitable for them to grow. This makes them likely candidates of life forms that could exist in Martian subsurface environments.
Dr. Kral’s laboratory has demonstrated that if provided with proper nutrients, select methanogens show growth in subsurface Martian conditions. The different organisms require slightly different growth media, but they all contain four base solutions. These solutions, labeled A, B, C, and D, are understood to be a requirement to grow these organisms. My project centers around attempting to grow the organisms without one of the solutions present. This solution is called “Solution D”. Methane is a product of methanogen metabolism; therefore, it was used to follow methanogen growth throughout the experiment.
The organisms studied include Methanothermobacter wolfeii, Methanosarcina barkeri, Methanobacterium formicicum, and Methanococcus maripaludis. All methanogens except for M. maripaludis showed growth in media lacking Solution D. This could be attributed to a few different things, but most likely reflects the fact that only a small amount of trace minerals are necessary for some of these methanogens’ growth.
The growth of these methanogens outside of their typical growth medium was also observed. Organisms were incubated in the simplest medium rather than their preferred/more complex media and observed (this time with Solution D present). When incubated in the simplest medium, all organisms showed limited growth. Some organisms showed far less growth than they did in their typical medium lacking Solution D.
These results indicate that subsurface areas of Mars lacking an abundance of the trace minerals that Solution D contains may be hospitable for methanogens for a limited period. They also indicate that these methanogens may be able to survive in Martian environments lacking an abundance of other usual growth requirements for limited periods as well.
This project was generously supported by the Honors College Research Grant, and I’m grateful for being given the opportunity to do such interesting research. Support from the Honors College as well as my mentor have made it possible to fully delve into my project.