Authors: Lindsey Kuchenbecker
Faculty Mentor: Brent Christner
College: College of Agricultural and Life Sciences
Methane is a potent greenhouse gas with 30-times the heat trapping capacity of CO2. Methanotrophs are microorganisms that use methane carbon for biomass and oxidize it to carbon dioxide as a metabolic byproduct. Mercer Subglacial Lake (SLM), West Antarctica is an aquatic environment that exists beneath ~1100 m of ice and contains a microbial community in which methane is cycled within in the aerobic water column and surficial sediments (0-30 cm). Enrichment cultures containing methane that were analyzed by gas chromatography identified samples in which methane oxidation had occurred. From these samples, methane oxidizing bacteria were isolated using minimal nitrate mineral salts media amended with methane as the sole carbon source. Amplification and sequencing of the particulate methane monooxygenase (pMOA) gene was used to identify various methanotrophic strains within the genera Methylomonas and isolate them in pure culture. Methanotrophs in environments beneath ice sheets are poorly understood, yet they have the potential to have an important impact on mitigating the release of methane in runoff and during deglaciation. Elucidating the characteristics of these bacteria can provide insight on how carbon is cycled beneath the West Antarctica Ice Sheet and their role as a biological sink for methane.