Biogeochemical and historical drivers of microbial community composition and structure in sediments from Mercer Subglacial Lake, West Antarctica ...

• Main Authors: Davis, Christina B., Venturelli, Ryan R., Michaud, Alexander M., Hawkings, Jon J., Achberger, Amanda E., Vick-Majors, Trista E., Rosenheim, Brad, Dore, John L., Steigmeyer, August D., Benning, Liane G.
• Format: Text
• Language: unknown
• Published: Freie Universität Berlin 2023
• Subjects: microbial community composition; microbial structure; sediments; 500 Naturwissenschaften und Mathematik570 Biowissenschaften; Biologie570 Biowissenschaften; Biologie; Antarctic; Mercer; Mercer Ice Stream; Ross Ice Shelf; West Antarctic Ice Sheet; West Antarctica; Antarc*; Antarctica; Ice Sheet; Ice Shelf
• Online Access: https://dx.doi.org/10.17169/refubium-40917; https://refubium.fu-berlin.de/handle/fub188/41196

Ice streams that flow into Ross Ice Shelf are underlain by water-saturated sediments, a dynamic hydrological system, and subglacial lakes that intermittently discharge water downstream across grounding zones of West Antarctic Ice Sheet (WAIS). A 2.06 m composite sediment profile was recently recovered from Mercer Subglacial Lake, a 15 m deep water cavity beneath a 1087 m thick portion of the Mercer Ice Stream. We examined microbial abundances, used 16S rRNA gene amplicon sequencing to assess community structures, and characterized extracellular polymeric substances (EPS) associated with distinct lithologic units in the sediments. Bacterial and archaeal communities in the surficial sediments are more abundant and diverse, with significantly different compositions from those found deeper in the sediment column. The most abundant taxa are related to chemolithoautotrophs capable of oxidizing reduced nitrogen, sulfur, and iron compounds with oxygen, nitrate, or iron. Concentrations of dissolved methane and total ...