Date of Graduation
5-2025
Document Type
Thesis
Degree Name
Bachelor of Arts
Degree Level
Undergraduate
Department
Biological Sciences
Advisor/Mentor
Kral, Timothy
Committee Member
Lessner, Daniel
Second Committee Member
Diaz Gonzalez, Delmy J.
Third Committee Member
D'Eugenio, Daniela
Abstract
The possibility of extraterrestrial life, particularly on Mars, remains a compelling question in astrobiology. Mars' harsh atmospheric conditions, dominated by carbon dioxide and extreme cold, prevent the survival of aerobic species. However, it still leaves the possibility of methanogens, an anaerobic species that can survive in extreme conditions, to inhabit this planet. Due to the discovery of methane on Mars, it is possible that methanogens may live and grow in the subsurface of this planet.
For this experiment, basalt and montmorillonite clay were chosen as substrates because they are believed to be found in the composition of Mars's subsurface. Methane, a product of methanogen metabolism, was measured to indicate if Methanothermobacter wolfeii, Methanosarcina barkeri, Methanobacterium formicicum, or Methanococcus maripaludis, could live on the nutrients the substrates provided. This would help decipher if different strains of methanogens could possibly survive on Mars.
Results from initial experiments revealed that M. wolfeii, M. barkeri, and M. formicicum efficiently utilized nutrients from the basalt in a bicarbonate buffer. Subsequent transfer experiments showed sustained growth for M. wolfeii and M. barkeri, with final transfers indicating that basalt might supply sufficient nutrients to support M. barkeri alone. Additional experiments with montmorillonite clay demonstrated higher methane production with 0.5 grams of montmorillonite clay compared to 0.05 grams, suggesting that nutrient availability in clay-rich media could mimic Mars' subsurface conditions with limited liquid water.
The data from both experiments further suggest that life may be possible on Mars. It also suggests that the subsurface components of this planet can provide enough nutrients for certain methanogen strains to survive.
Keywords
methanogens; mars; methane; basalt; montmorillonite clay
Citation
Ezeldin, A. (2025). Justification for the Biological Foundation of Methane on Mars: Methanogens’ Capacity to Metabolize on Montmorillonite Clay and Basalt. Biological Sciences Undergraduate Honors Theses Retrieved from https://scholarworks.uark.edu/biscuht/116
